to my family · dicted and experimentally observed states of the nucleus. they do, however, give...

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MICROSCOPIC BASES OF COLLECTIVITY IN LIGHT NUCLEI Marvin I. Friedman 1970 A Dissertation Presented to the Faculty of the Graduate School of Yale University in Candidacy for the Degree of Doctor of Philosophy

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Page 1: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

MICROSCOPIC BASES OF COLLECTIVITY IN LIGHT NUCLEI

Marvin I. Friedman 1970

A Dissertation Presented to the Faculty of the Graduate School of Yale University

in Candidacy for the Degree of Doctor of Philosophy

Page 2: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T O M Y F A M I L Y

v

Page 3: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

ACKNOWLEDGMENTS

I t i s a g r e a t p le a s u re to acknow ledge my a p p r e c ia t io n

to th e p e o p le who have made t h is d is s e r t a t io n p o s s ib le .

The s t a f f o f th e A tom ic Energy Commission Computer

C e n te r a t th e New Y o rk U n iv e r s i t y C ouran t I n s t i t u t e o f

M ath e m a tics was v e ry h e lp f u l In th e ru n n in g o f com puter

codes .

I w ould l i k e to exp ress my g r a t i t u d e f o r th e h o s p i t a l i t y

shown to me a t T e l - A v iv U n iv e r s i t y , I s r a e l . The s t a f f th e r e

was o f g r e a t a s s is ta n c e in th e p e r fo rm in g o f a n a ly s is c a lc u ­

la t i o n s . My v i s i t was a most memorable e x p e r ie n c e .

My a s s o c ia t io n w ith th e W rig h t N u c le a r S t r u c tu r e L ab o ra ­

to r y is g r a t e f u l l y ackn ow led ged . I am in d e b te d to my f e l lo w

g ra d u a te s tu d e n ts and c o lle a g u e s th e r e f o r in t e r e s t in g d is ­

cu ss io n s d e a lin g w ith a l l a s p e c ts o f n u c le a r p h y s ic s . The

use o f th e com puting f a c i l i t i e s o f th e la b o r a to r y was o f g r e a t

im p o rta n c e to th e c o m p le tio n o f t h is w o rk .

My a s s o c ia t io n w ith P ro fe s s o r I t z h a k K e ls o n , b o th d u r in g

th e tim e he was a t Y a le U n iv e r s i t y , and a t T e l -A v iv U n iv e r s i t y ,

p ro v id e d s e v e r a l u n fo rg e ta b le e x p e r ie n c e s . H is g u id an ce

th ro u g h o u t my g ra d u a te c a re e r is d e e p ly a p p r e c ia te d .

I t i s w ith trem endous p le a s u re t h a t I e x p res s my g r a t i t u d e

to P ro fe s s o r D . A l la n B ro m ley , th e d i r e c t o r o f t h is d is s e r t a ­

t i o n , f o r h is p a t ie n t g u id an ce and a s s is ta n c e in th e a n a ly s is

p e rfo rm e d h e r e in . Numerous in v a lu a b le d is c u s s io n s c o n c e rn in g

t h is w ork w i l l be lo n g rem em bered.

Page 4: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

ABSTRACTIn an a tte m p t to e lu c id a te th e m ic ro s c o p ic bases o f

c o l l e c t i v i t y in l i g h t n u c le i , i n d i v i d u a l - p a r t i c l e model c a lc u la t io n s have been p e rfo rm ed u s in g b o th r e a l i s t i c and n o n - r e a l i s t i c n u c le a r models w ith th e a id o f a n g u la r momen­tum p r o je c t io n te c h n iq u e s . M a t r ix methods f o r p r o je c t io n fro m s e v e r a l " i n t r i n s i c " s ta te s o f th e n u c leu s a re d isc u s s e d and d e v e lo p e d . In a d d i t io n , a p o ly n o m ia l p r o je c t io n method w hich is e x tre m e ly u s e fu l in c o n s id e r in g system s o f n e u tro n s and p ro to n s is in tro d u c e d . I t a llo w s f o r t r e a tm e n t o f th e H i lb e r t spaces o f th e two n u c leo n s ta te s as s e p a ra te e n t i t i e s , w hich m ay, a t c o n c lu s io n , be combined in t o th e H i lb e r t space o f th e e n t i r e n u c le u s .

The p h en o m en o lo g ica l p a ir in g -p lu s -q u a d r u p o le n u c le o n - n u c le o n in t e r a c t io n is s tu d ie d in ( j ) n n e u tro n c o n f ig u r a ­t io n s , 7 /2 $ /« 1 5 /2 . The n-body H a m ilto n ia n o p e ra to r is p a ra m e te r iz e d in term s o f i t s tw o-body m a tr ix e le m e n ts , e n a b lin g f u r t h e r c a lc u la t io n s , f o r any g iv e n s c a la r o p e r a to r , to be p e rfo rm e d s im p ly w ith th e s p e c i f ic a t io n o f i t s m a tr ix e le m e n ts . C o m p le te , e x a c t s p e c tra a re o b ta in e d f o r th e ( j ) n c o n f ig u r a t io n s th ro u g h !th e a p p l ic a t io n o f th e m a tr ix p r o je c ­t io n te c h n iq u e s . E ig e n fu n c t io n s a re a n a ly z e d in s e n io r i t y space w ith p a r t i c u l a r re g a rd to w ard th e e x h ib i t io n o f c o l l e c ­t i v e p r o p e r t ie s . V a r io u s e x p e r im e n ta l ly ob served phenomena a re a t t r i b u t e d to th e n a tu re o f th e s im p le , b u t b a s ic , phe­n o m e n o lo g ic a l fo r c e s .

O ne- and t w o - p a r t ic le /h o le e x c i t a t io n s a re c o n s id ­e re d as a mechanism f o r " s c a t te r in g " n u cleo n s ac ro ss th e f i n i t e en erg y gap a p p e a r in g betw een o ccu p ie d and unoccup ied H a r tr e e -F o c k deform ed o r b i t a l s o f e v e n -e v e n , N=Z n u c le i in th e 24 -Id. s h e l l . A dm ix tu res o f th e s e c o n f ig u r a t io n s to th e H a r tre e -F o c k s t a te a re [found to be m in im a l and in a d e q u a te to acco u n t f o r th e d is c re p a n c ie s betw een t h e o r e t i c a l l y p r e ­d ic te d and e x p e r im e n ta l ly o b served s ta te s o f th e n u c le u s .They d o , h o w ever, g iv e q u a l i t a t i v e e x p la n a t io n to th e lo w - en erg y e x c i te d n u c le a r c o n f ig u r a t io n s found to l i e w i t h in o r above th e q u a s i - r o t a t io n a l H a r tre e -F o c k s p ec tru m . S hape- m ix in g c a lc u la t io n s a re d isc u s s e d as a means o f c o r r e c t ly p r e d ic t in g p r o p e r t ie s o f e ig e n s ta te s In th e lo w -e n e rg y re g io n o f e x c i t a t i o n . I t is sugg ested t h a t th e o b je c t io n a b le use o f a s in g le dt^oAmzd n u c le a r c o n f ig u r a t io n as in p u t to th e c a lc u la t io n s , r a t h e r th a n as o u tp u t , may be e l im in a te d by v a r i a t i o n o f th e wave fu n c t io n s a f t e r p r o je c t io n , r a th e r th a n b e fo r e .

Page 5: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

TABLE.OF CONTENTS

1 . G e n e ra l C o n s id e ra t io n s ................................................................... 1

2 . The D evelopm ent o f N u c le a r M odels

a . D i r e c t io n s ....................................................................................... 4

b . In d iv id u a l P a r t i c le M o d e ls ............................................ 4

c . C o l le c t iv e M o d e ls ....................................................................... 12

d . U n if ie d M o d e ls .............................................................................

3 . A n g u la r Momentum P r o je c t io n ........................................................ 15

4 . M o t iv a t io n f o r S tu d ie s .....................................................................16

5 . Scope o f P re s e n t I n v e s t i g a t i o n s . * ......................................... 18

C h a p te r I I - P r o je c t io n Techn iques

1 . P r e l im in a r y D is c u s s io n .................................................................... 22

2 . A n g u la r Momentum P r o je c t io n by F i n i t e R o ta t io n s . . 27

3 . I n f i n i t e s i m a l R o ta t io n O p e ra to r P r o je c t io n

P rocesses

a . N o r m a l iz a t io n s .............................................................................. 30

b . T e n s o r O p e r a to r s ......................................................................... 34

c . S c a la r O p e r a to rs ..........................................................................37

4 . A N e u tro n -P ro to n P o ly n o m ia l P r o je c t io n T ech n iq u e

a . In t r o d u c t io n ....................................................................................38

b . Is o to p ic S p in C o n s id e r a t io n s ............................................40

c . P r o je c t io n Method - N o r m a l iz a t io n s ............................. 41

d . P r o je c t io n Method - E n e r g ie s ...........................................43

Chapter I - Introduction

Page 6: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1 . In t r o d u c t io n ................................................ 47

2 . P a ir in g + Q uadrupo le M odel

a . In t r o d u c t io n ...................................................................................... 50

b . The Q u ad ru p o le -Q u a d ru p o le F o r c e ......................................... 53

c . The S e n io r i t y Quantum Number and th e P a ir in g

I n t e r a c t i o n ........................................................................................ 57

3 . The H a m ilto n ia n o f th e In d i v i d u a l - P a r t i c l e M o d e l . . . 63

4 . S e n io r i t y C o m p o s itio n o f Wave F u n c t io n s .............................. 65

5 . R e s u lts o f C a lc u la t io n s - Even Number o f P a r t ic le s

a . D is t o r t io n o f R o ta t io n a l Bands a t H igh A n g u la r

Momentum V a lu e s ................................ 66

b . S e n io r i t y A n a ly s is and V ib r a t io n s A r is in g from

th e Long Range I n t e r a c t i o n ................................................... 69

6 . R e s u lts o f C a lc u la t io n s - Odd Number o f P a r t i c l e s . . 73

7 . Summary.............................................................................................................. 77

C h a p te r IV - H a r tre e -F o c k S tu d ie s

1 . In t r o d u c t io n ................................................................................................. 79

2 . H a r tre e -F o c k E q u a tio n s ........................................................................ 85

3 . Sym m etries o f th e H a r tre e -F o c k S o lu t io n s ........................... 90

4 . H a r tre e -F o c k C a lc u la t io n s ................................................................ 93

5 . P a r t ic le - H o le A d m ix tu res to H a r tre e -F o c k

a . P r e l im in a r y D is c u s s io n .............................................................. 102

b . Is o to p ic S p in C o n s id e ra t io n s ...............................................104

c . The Use o f R e fe re n c e N u c le i and H o le S t a t e s . . . . 108

d . P r o je c t io n E q u a tio n s and Wave F u n c tio n

A n a ly s is ................................................................................................. 112

Chapter III - Studies in Single / Configurations

Page 7: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

6 . R e s u lts o f C a lc u la t io n s

a . G e n e ra l R em arks............................................................................ 115

b . Neon 2 0 .................................................................................................H g

c . Magnesium 2 4 ....................................................................................119

d . S i l ic o n 2 8 ......................................................................................... 122

e . S u l f u r 3 2 ........................................................................................... 126

f. Argon 36......................................... 1287 . Summary........................................................................................................... 129

C h a p te r V - Summary and C o n c lu s io n s ............................................................ 132

References..................................................... 135

A ppendices

A - I M a th e m a tic a l F o o tn o te s

1 . The Group U3 ....................................................................................141

2 . The M a t r ix E lem ents <jm\y^\jtn> .......................................142

A - I I C o l le c t iv e N ucleon M o tio n s

1 . The N u c le a r S u r fa c e ............................................................. . . 1 4 5

2 . C o u p lin g to th e N u c le a r S u r fa c e ....................................... 148

B - I ( / ) n Com puter Codes

1 . P r o je c t io n C ode.............................................................................153

2 . A n a ly s is C ode..................................................................................I 65

B - I I P a r t i c le H o le Com puter Code

1 . In p u t C ode......................................................................................... 169

2 . PHEXCIT .................................................................................................175

B - I I I G e n e ra l Purpose Computer C odes................................................ 200

Page 8: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1

The te rm " n u c le a r s t r u c tu r e " encompasses a l l m ic ro s c o p ic

a n d /o r m acroscop ic a s p e c ts o f th e m o tio n o f n u c leo n s bound

to g e th e r to fo rm a n u c le u s , e . g . , s p a t ia l p a th s , momentum

d i s t r ib u t io n s , a n g u la r momenta, n u c leo n c o r r e la t io n s , b in d in g

e n e r g ie s , n u c le a r sh ap es , e t c . T h e o r e t ic a l ly a l l o f t h is

In fo r m a t io n is em bodied w i t h in th e t r u e com ple te n u c le a r wave

f u n c t io n s , and may be o b ta in e d by a p p l ic a t io n o f th e a p p r o p r i­

a te quantum m e c h a n ic a l o p e r a to r s . Wave fu n c t io n s f o r th e

n u c le a r m any-body system may be w r i t t e n in a v a r ie t y o f w ays;

th e most u s e fu l o f th e s e em phasizes th e p h y s ic a l ly s ig n i f i c a n t

a s p e c ts o f th e p a r t i c u l a r n u c le a r system u n d e rg o in g in v e s t ig a ­

t i o n . F o r e xam p le , th e p resen ce o f c o r r e la te d m otio ns in

some n u c le i may make i t advantageous to choose a d e s c r ip t io n

w hich a c c e n tu a te s e i t h e r c o l l e c t i v e o r p a ir e d -n u c le o n degrees

o f free d o m ; in o th e r cases th e m o tio n o f c e r t a in in d iv id u a l

n u c leo n s may be em phasized because many o f th e o b s e rv a b le

phenomena a p p e a r to be a t t r i b u t a b l e to o n ly a few r e l a t i v e l y

a c t iv e p a r t i c l e s .

A t p re s e n t I t is im p o s s ib le to d e s c r ib e th e b e h a v io r

o f a l l o f th e degrees o f freedom o f th e in d iv id u a l nu c leo ns

c o m p ris in g a dynam ic n u c le u s . T h is is t r u e p a r t l y because

no c lo s e d t h e o r e t ic a l e x p re s s io n has y e t been found f o r th e

n u c le o n -n u c le o n fo r c e . Even I f such an e x p re s s io n w ere known

CHAPTER I

INTRODUCTION

1. General Considerations

Page 9: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

f o r e x t r a - n u c le a r p a r t i c l e s , h o w ever, i t w ould have to be

m o d if ie d in s id e th e n u c leu s where th e p resen ce o f o th e r

p a r t ic le s s e v e r e ly l i m i t s th e p o s s ib le f i n a l s ta te s to w h ich

a n u c leo n may s c a t t e r as a r e s u l t o f i t s in t e r a c t io n s .

T h is p ro b lem has been bypassed somewhat by th e em ploy­

ment c f e f f e c t i v e in t e r a c t io n s . We assume t h a t we a re g iv e n

a H a m ilto n ia n H = H + V , w itho

h0 ■ i h0(i> - 1 [T(1) + v i ) ]° 1=1 ° i = l °

V = I U ( i , j ) - I V ( i ) . i < j i = l 0

T ( J ) i s th e k in e t i c en erg y o f th e p a r t i c l e ; U ( i , j ) th e

tw o -b ody in t e r a c t io n betw een th e i th and p a r t i c l e s ; V Q( j )

some c o n v e n ie n t one-body o p e ra to r w h ich s im p l i f ie s th e p ro b lem .

The H a m ilto n ia n H is e x a c t and c o n s is ts o f two p a r ts : Hq , a

one-body o p e r a to r , and V , th e " e f f e c t iv e in t e r a c t io n " . I t i s

hoped t h a t by p ro p er, c h o ic e o f VQ( J ) , th e e f f e c t i v e in t e r a c ­

t io n may be t r e a t e d by p e r t u r b a t iv e te c h n iq u e s , i . e . , i t s

e f f e c t i s s m a ll com pared to t h a t o f Hq . The e f f e c t i v e i n t e r ­

a c t io n may have l i t t l e to do w ith th e a c tu a l in t e r a c t io n

betw een n u c leo n s w i t h in th e n u c le u s . P a s t e f f o r t s have been

a lo n g fo u r d i s t i n c t l i n e s : ( i ) The e f f e c t i v e in t e r a c t io n is

assumed to ta k e some s im p le and re a s o n a b le fo rm . S tr e n g th s ,

ran g es and m ix tu re c o n s ta n ts a re c o n s id e re d p a ra m e te rs w h ich

a re o b ta in e d by f i t s to e x p e r im e n ta l d a t a . 1 ( i i ) The i n t e r ­

a c t io n m a tr ix e le m en ts th em selves a re c o n s id e re d d i r e c t l y as

Page 10: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

3

a d ju s ta b le p a ra m e te rs w ith o u t s p e c ify in g t h e i r a lg e b r a ic

fo rm s . 2 ( i i i ) M a t r ix e lem en ts a re d e te rm in e d d i r e c t l y from

th e e x p e r im e n ta l s p e c tra o f p a r t i c u l a r l y s im p le n u c le i .

( i v ) The e f f e c t i v e in t e r a c t io n is d e r iv e d from f r e e n u c le o n -

n u c le o n s c a t t e r in g p o te n t ia ls a d ju s te d to f i t d e u te ro n

p r o p e r t ie s and s c a t t e r in g d a ta up to a p p ro x im a te ly 350 MeV.

E f f e c t iv e m a tr ix e lem en ts a re c a lc u la te d u s in g re a s o n a b le

assum ptions a p p l ic a b le to th e n u c le a r m any-body p ro b le m . 3""6

I n a c t u a l i t y , th e fo rm a l s o lu t io n o f th e p rob lem w ould

n o t c o n t r ib u te much to w ard th e u n d e rs ta n d in g o f n u c le a r

s t r u c t u r e ; th e com ple te n u c le a r wave fu n c t io n s a re to o com­

p l ic a t e d to p ro v id e any s im p le p h y s ic a l p ic t u r e o f th e n u c le u s .

A d e s c r ip t io n in term s o f fe w e r p a ra m e te rs must be found so

t h a t , h o p e f u l ly , n u c le i can be u n d ers to o d by th e human m ind

as w e l l as by e le c t r o n ic co m p u ters . T h is le a d s to th e concept

o f th e n u c le a r m o d e l, w h e re in c e r t a in a s p e c ts o f th e a c tu a l

pro b lem a re em phasized to th e e x c lu s io n o f o th e r s . T h is is

done to p ro v id e a m a th e m a tic a lly t r a c t a b le re p ro d u c t io n o f

c e r t a in o b s e rv a b le phenom ena, n o t s i g n i f i c a n t l y dependent

upon th e ig n o re d p a ra m e te rs o r n u c le a r degrees o f freed o m .

In e s s e n c e , th e n u c le a r m odel re p re s e n ts a c h a r ic a tu r e o f th e

com ple te n u c le a r p ro b le m . On th e b a s is o f an a c c e p ta b le

n u c le a r m odel i t sh o u ld be p o s s ib le to p r e d ic t most o f th e

im p o rta n t p r o p e r t ie s o f s p e c i f ic n u c le i u n d er s tu d y . In d e e d ,

th e u l t im a t e v a l i d i t y o f th e m odel is m easured by th e e x te n t

to w h ich i t s p r e d ic t io n s a g re e w ith subsequent o b s e rv a b le s

found by e x p e r im e n t.

Page 11: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

2 . The D evelopm ent o f N u c le a r M odels

a . D ir e c t io n s

The deve lopm ent o f n u c le a r m odels has been in two

seem in g ly opposing d i r e c t io n s , w ith a p p a re n t ly c o n t r a d ic to r y

a ssu m p tio n s . C o l le c t iv e m odels ( e . g . , th e l i q u i d drop m odel

f i r s t sug g ested by Bohr and W L e e le r7 ) p ic t u r e th e n u c leu s as

a c o n tin u o u s drop o f in c o m p re s s ib le n u c le a r m a t te r , th e shape8

o f w h ich may d e p a r t a p p r e c ia b ly from s p h e r i c i t y . . F o r a

s p h e r ic a l n u c le u s c o l l e c t i v e m otions co rresp o n d to s u r fa c e

v ib r a t io n s abou t th e e q u i l ib r iu m shape; th e m o tio n o f a

s p h e r o id a l n u c le u s , on th e o th e r h an d , can be c o n s id e re d as

a c o m b in a tio n o f r o t a t io n s o f a s t a t i c a l l y deform ed n u c le a r

co re and s u r fa c e v ib r a t io n s abou t an e q u i l ib r iu m d e fo rm a tio n .

A t th e o th e r ex trem e a re th e in d iv id u a l p a r t i c l e m o d e ls ,

a c c o rd in g to w h ich th e m o tio n o f any one g iv e n n u c leo n is

in f lu e n c e d d i r e c t l y by a l l o th e r n u c leo n s c o m p ris in g th e

n u c le u s . These m odels a re n o t e n t i r e l y In d e p e n d e n t; th e y

com plem ent each o th e r . In d iv id u a l p a r t i c l e m odels may be

co u p led to m odels o f c o l l e c t i v e m o tio n to produce th e s o -

c a l le d u n -t^ e d m o d e ls , 1 w h ich have le d to an e x p la n a t io n o f

a v a s t amount o f n u c le a r d a ta . In th e f i n a l a n a ly s is , a l l

o f th e s e re p re s e n t d i f f e r e n t a p p ro x im a tio n s to a th e o ry w hich

does n o t y e t e x i s t . The s tu d y o f th e r e l a t i o n betw een th e

m odels is t h e r e fo r e e s p e c ia l ly im p o r ta n t .

b . In d iv id u a l P a r t i c le M odels

In th e 1930s I t was d is c o v e re d t h a t n u c le i w ith c e r t a in

4

Page 12: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

p ro to n numbers Z , o r n e u tro n numbers N , known as "m agic

nu m b ers", e x h ib i t enhanced s t a b i l i t y , w h ich may be in t e r p r e t e d

as a r is in g fro m th e c lo s in g o f n u c le a r s h e l l s . In p a r t i c u l a r ,

th e f i r s t p ro to n o r n e u tro n beyond such a m agic number is le s s

bound th a n th e p re c e d in g nu cleo ns by 1 -2 MeV; th e c r o s s -s e c t io n

f o r c o rre s p o n d in g n u c leo n c a p tu re is r a th e r low f o r th e m agic

n u c le i , in d ic a t in g an anomalous d eg ree o f s t a b i l i t y ; th e e le c ­

t r i c q u ad ru p o le moment is v e ry s m a ll and in c re a s e s in m agni­

tu d e w ith th e a d d i t io n o f a n o th e r n u c le o n , in d ic a t in g th e •

em ergence o f s p h e r ic a l symmetry f o r th e m agic n u c le i . C le a r ly ,

s in c e c o l l e c t i v e m odels c o n ta in v e ry l i t t l e re fe r e n c e to th e

number o f n u c leo n s p r e s e n t , th e e x p la n a t io n o f th e s e phenomena

must be sought w i t h in th e fram ew ork o f in d iv id u a l p a r t i c l e

m o d e ls .

The e x p e r im e n ta l ly o b served d is c o n t in u i t ie s n o te d above

le d to th e in t r o d u c t io n o f th e s h e l l m odel o f n u c le a r s t r u c ­

t u r e , In d e p e n d e n t ly , by M ayer9 and by H a x e l t t a l . xo The

assu m p tio n o f an u n d e r ly in g n u c le a r s h e l l s t r u c tu r e makes i t

o f i n t e r e s t to exam ine th e o r ie s o f n u c le a r p h y s ic s w h ich a re

p a r a l l e l to th o s e o f a to m ic p h y s ic s . I t w ould be te m p tin g

to d e s c r ib e th e e f f e c t i v e fo rc e a c t in g on each n u c leo n by

means o f a c e n t r a l p o t e n t i a l V ( / l ) , an a lag o u s to th e in t e r a c ­

t io n o f a to m ic e le c t r o n s w ith th e c e n t r a l e l e c t r i c f i e l d

g e n e ra te d by th e n u c leu s and in n e r e le c t r o n s . H ow ever, a p a r t

fro m th e above m e n tio n ed f a c t t h a t th e n u c le a r fo rc e is un­

known, a f u r t h e r p ro b lem im m e d ia te ly a r is e s — th e re is no

n a t u r a l c e n t e r - o f - f o r c e f o r th e n u c le o n s . In l i e u o f t h is

5

Page 13: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

6

c o n c e p t, i t i s assumed t h a t th e n u c le a r p o t e n t i a l re p re s e n ts

an a v era g e o v e r n u c leo n m o tio n s . A c c o rd in g ly , th e c e n t e r - o f -

fo r c e does n o t have any s p e c ia l p h y s ic a l s ig n i f ic a n c e , b u t

m e re ly c o in c id e s w ith th e c e n te r -o f-m a s s o f th e n u c le u s .

T h u s , as a f i r s t a p p ro x im a tio n , th e fo rc e b in d in g each

n u c leo n to th e c e n te r -o f-m a s s o f th e n u c leu s is assumed cen­

t r a l . I t seems p la u s ib le to assume t h a t th e a v e ra g e fo r c e

a c t in g on a n u c leo n lo c a te d a t th e c e n te r o f th e n u c leu s must

v a n is h . T h is im p lie s t h a t th e p o t e n t ia l I s f l a t in t h is

r e g io n . A p o t e n t i a l w h ich s a t i s f i e s th e s e re q u ire m e n ts and

i s m a th e m a t ic a lly s im p le to w ork w ith is t h a t o f th e is o ­

t r o p ic harm on ic o s c i l l a t o r

V (; t ) = -V + A Mw2* 2 ,O 2

where VQ is th e p o t e n t i a l d e p th , M th e mass o f th e o s c i l l a t i n g

p a r t i c l e , w th e c la s s ic a l a n g u la r fre q u e n c y o f o s c i l l a t i o n ,

and A th e d is ta n c e o f th e p a r t i c l e from th e c e n te r o f o s c i l l a - +

t i o n . I f th e harm onic o s c i l l a t o r p o t e n t i a l is to be o f u s e ,

i t must in some way be a b le to rep ro d u ce th e m agic num bers.

U n fo r tu n a te ly , h o w ever, I t g e n e ra te s a s i n g l e - p a r t i c l e spectru m

w ith en erg y gaps a t p a r t i c l e numbers w hich a g ree w ith o n ly th e

f i r s t th r e e m agic num bers.

^ I t must be borne in m in d , h o w ever, t h a t th e harm onic o s c i l ­l a t o r p o t e n t i a l cannot be r e a l i s t i c f o r o th e r th a n r a th e r s t r o n g ly bound s ta te s inasm uch as i t cannot rep ro d u ce e i t h e r an unbound s ta te o r th e b e h a v io r o f n u c le a r wave fu n c t io n s o f s l i g h t l y bound s t a t e s , p a r t i c u l a r l y in th e re g io n o f th e n u c le a r s u r fa c e .

Page 14: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

7

The o b s e rv a t io n o f s p in - o r b i t d o u b le ts , p a r t i c u l a r l y5 5 17 17th o s e in He and L i , and l a t e r in 0 and F , sugg ested

th e s tro n g c o u p lin g o f th e i n t r i n s i c s p in a n g u la r momentum

s o f th e n u c leo n to th e o th e rw is e f ix e d o r b i t a l a n g u la r

momentum Z o f th e n u c leo n v ia th e s p in - o r b i t p o t e n t ia l

V = -V U ) L s , w here Is a c e n t r a l s c a la r p o t e n t ia lo U S O S O

d epend ing on th e d is ta n c e fi o f th e n u c leo n from th e c e n t e r -

o f-m ass o f th e n u c le u s . T h is in tro d u c e s an a d d i t io n a l quantum

number 7 > th e t o t a l a n g u la r momentum o f th e n u c le o n , g iv e n by

7 “ Z + s , w h ich has th e c o n s ta n t m agnitude / / ( / + ) ) . The

s p in - o r b i t p o t e n t i a l does n o t m ix s ta te s o f d i f f e r e n t I s in c e

Z2 commutes w ith Z ' S ; th e p r o je c t io n o f Z o n to th e a x is o f

q u a n t iz a t io n , h o w ever, is no lo n g e r a c o n s ta n t o f th e m o tio n ,

and o n ly 7 has a f ix e d component on th e q u a n t iz a t io n a x is .

S in ce th e i n t r i n s i c s p in o f a n u c leo n is 1 /2 , th e r e a re

o n ly two p o s s ib le v a lu e s o f th e t o t a l a n g u la r momentum / f o r

a g iv e n l - - j s I *—. The en erg y o f a n u c leo n h a v in g a n g u la r2momentum j w i l l depend on w hich o f th e s e two o r ie n t a t io n s o f

/ th e n u c le o n assum es. S in ce th e e ig e n v a lu e s o f 2 *s in s ta te s

o f / » l + — and j - L - — a re £ / 2 and - ( £ + / ) / 2 , r e s p e c t iv e ly , i t 2 2

may im m e d ia te ly be seen t h a t th e en erg y d i f fe r e n c e betw een

th e s e s ta te s is p r o p o r t io n a l to 2 Z + I; w ith V ( * ) p o s i t i v e ,s o

th e s ta te w ith h ig h e r / l i e s lo w e r In e n e rg y .

I f th e c e n t r a l s c a la r p o t e n t ia l b in d in g n u cleo n s to th e

c e n te r -o f-m a s s is chosen to be t h a t o f a harm onic o s c i l l a t o r ,

w h ic h , as n o te d ab o ve , is f r e q u e n t ly th e case , th e quantum

* The shape o f th e a c t u a l p o t e n t i a l w e l l l i e s somewhere betw een

Page 15: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

8

numbers f o r a s in g le p a r t i c l e o r b i t a re th e s e t ( n , £ , / ) , n

b e in g th e o s c i l l a t o r quantum num ber. The group o f s ta te s

c o rre s p o n d in g to th e quantum number N + l (N = 2n+1) i s b ro ken

up by th e s p in - o r b i t i n t e r a c t io n , and th e s t a te w ith th e

h ig h e s t s in g le p a r t i c l e a n g u la r momentum is lo w e re d to w ard

th e group o f o s c i l l a t o r s ta te s w ith quantum number N . Some

s in g l e - p a r t i c l e o r b i t s fro m t h is group a re r a is e d as a con­

sequence o f th e s p in - o r b i t in t e r a c t io n , r e s u l t in g In a re g io n

c o n ta in in g s ta te s from th e groups w ith quantum numbers N and

N + l. S in g le - p a r t i c le o r b i t s w h ich l i e c lo s e in en erg y com prise

a s in g le m a jo r s h e l l ; when a l l s in g l e - p a r t i c l e o r b i t s in a

m a jo r s h e l l a re f i l l e d , we speak o f a c lo s e d s h e l l . The s p in -

o r b i t fo rc e produces en erg y gaps betw een c lo s e d s h e l ls w h ich

c o in c id e w ith th e o b served m agic num bers.

S in ce th e r e is o n ly one t o t a l l y a n tis y m m e tr ic quantum

m e c h a n ic a l s t a te f o r a c lo s e d s h e l l , m agic n u c le i a re n eces ­

s a r i l y e x c i te d by m oving p a r t ic le s in t o h ig h e r s h e l l s . How­

e v e r , c o n s id e ra b le amounts o f energy a re needed to s c a t t e r

ac ro s s th e s in g le p a r t i c l e en erg y g a p s , whence th e e x t r a

s t a b i l i t y a s s o c ia te d w ith m agic num bers. The mean f r e e p a th ,

i . e . , th e d is ta n c e a n u c leo n can t r a v e l in s id e th e n u c leu s

w ith o u t u n d erg o in g c o l l is io n s w ith o th e r n u c le o n s , i s p r e d ic te d

to be h ig h because o f th e P a u l i p r in c ip le w h ich in h i b i t s c o l -

an o s c i l l a t o r p o t e n t ia l and a square w e l l w ith a t a i l . Harm onic o s c i l l a t o r s ta te s a re used m e re ly as a m a tte r o f m a th e m a tic a l c o n v e n ie n c e . C o n s id e ra b le work has been acco m p lish ed u s in g o th e r form s f o r th e c e n t r a l p o t e n t i a l , e . g . , th e Woods-Saxon p o t e n t i a l , e s p e c ia l ly in th e a n a ly s is o f th e m u lt ip o le and t r a n s i t i o n p r o p e r t ie s o f e x c ite d s t a t e s , w h ich a re more sen­s i t i v e to th e d e t a i l s o f th e p o t e n t ia l th a n th e en erg y spectrum i s .

Page 16: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

9

l i s io n s i f th e quantum s ta te s to w h ich th e c o l l id i n g fe rm io n s

can s c a t t e r a re a lr e a d y f i l l e d . T h is is o n ly t r u e because

n u c le a r e n e rg ie s a re e x tre m e ly lo w . T y p ic a l n u c leo n e n e rg ie s

i n bound s ta te s a re to o low to p e rm it c o l l is io n s w h e re in th e

p ro d u c ts a re prom oted to p r e v io u s ly open o r b i t s .

One o f th e e a r l i e s t a tte m p ts to em ploy th e s h e l l m odel

to u n d e rs ta n d th e s y s te m a tic b e h a v io r o f n u c le i in v o lv e d th e

E xtrem e S in g le P a r t i c le M odel (ESPM ), a c c o rd in g to w hich

in d iv id u a l n u c leo n s a re c o n s id e re d to move in s ta t io n a r y s h e l l

m odel o r b i t s w ith f ix e d a n g u la r momentum / . I t I s assumed

t h a t n e u tro n and p ro to n s ta te s f i l l in o r d e r , in d e p e n d e n t ly ,

i . e . , th e s t a te to be f i l l e d by an a d d i t io n a l n e u tro n Is

in d e p e n d e n t o f th e number o f p ro to n s , and v ic e v e rs a . The

n u c leo n s a re th e n p a ir e d o f f in such a way t h a t th e v a lu e s

o f many n u c le a r p a ra m e te rs a re d e te rm in e d s o le ly by any

rem nant s in g le u n p a ire d n u c le o n . T h u s , a c c o rd in g to t h is

m o d e l, a l l e v e n -e v e n n u c le i have z e ro ground s ta te s p in ,

w hich a g re es w ith e x p e r im e n t; odd-A n u c le i have th e s p in o f

th e l a s t u n p a ire d p a r t i c l e , w h ich is g e n e r a l ly t r u e ; odd-odd

s p in s can n o t be p r e d ic te d d i r e c t l y s in c e th e re is n o th in g to

in d ic a t e w h ich r e s u l t a n t c o u p lin g o f th e u n p a ire d n e u tro n and

p ro to n a n g u la r momenta w i l l have th e lo w e s t e n e rg y .^ C o l le c ­

t i v e m otio ns o f many n u cleo n s a r e , o f c o u rs e , n o t p o s s ib le

w it h in th e m odel fram ew o rk .

*f* The "N ordheim r u le s " a re g e n e r a l ly s u c c e s s fu l In p r e d ic ­t io n s o f s p in s o f odd-odd n u c le i . The Nordheim number is d e f in e d as N = j - I + j - I , where p and n r e f e r to th e odd p ro to n and n e u t r 8n , pr e § p e c t iv e ly . A cco rd in g to th e r u l e , i f N =0, J = l / n -J p l> and i f N = ± l, J i s e i t h e r T / n- J p l o r Jn+ Jp *

Page 17: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

10

The m ag n e tic moment o f odd-A n u c le i is a t t r i b u t e d to b o th

th e o r b i t a l and s p in a n g u la r momenta o f th e la s t u n p a ire d

n u c le o n . T h is g iv e s r i s e to two v a lu e s f o r th e m ag n e tic moment

o f th e n u c le u s , one c o rre s p o n d in g to s ta te s in w h ich th e s p in

and o r b i t a l a n g u la r momenta a re p a r a l l e l (/= •£+—) , and th e2

o th e r to s ta te s in w h ich th e y a re a n t i p a r a l l e l ( / = £ - —) . P lo ts2

g iv in g th e m ag n e tic moment as a fu n c t io n o f / a re known as

Schm idt l i n e s 1 1 . E x p e r im e n ta l ly , I t is o b served t h a t a lth o u g h

th e m easured m ag n e tic moments do n o t show such s im p le s y s te ­

m a t ic s , th o s e f o r odd mass n u c le i f a l l ro u g h ly in t o two

g ro u p s , one n e a r each o f th e Schm idt l i n e s ; e s s e n t ia l ly a l l

odd mass n u c le i have m ag n e tic moments betw een th e two Schm idt

l i m i t s .

The m odel p r e d ic ts e x c i te d s ta te s w h ich d u p l ic a te th e

s i n g l e - p a r t i c l e s p e c tru m , i . e . , th e u n p a ire d n u c le o n , in s te a d

o f o ccu p y in g th e lo w e s t s in g l e - p a r t i c l e s t a te a v a i l a b le , may

be e x c i te d to a h ig h e r o r b i t w i t h in th e m a jo r s h e l l . T h is

i s o b served e x p e r im e n ta l ly in th e lo w - ly in g s p e c tra o f n e a r ­

c lo s e d s h e l l n u c le i . The s p in s and p a r i t i e s o f th e s e e x p e r i ­

m e n ta lly o b served le v e ls a g re e v e ry w e l l w ith th e s h e l l m odel

a s s ig n m e n ts .

A c c o rd in g to th e P a u l i p r i n c i p l e , th e wave fu n c t io n o f

i d e n t i c a l n u c leo n s o u ts id e o f a c lo s e d s h e l l must be t o t a l l y

a n t is y m m e tr ic . O b v io u s ly , any more q u a n t i t a t iv e n u c le a r

m odel must ta k e in t o acco u n t n o t o n ly th e u n p a ire d n u c le o n s ,

as does th e ESPM, b u t r a th e r th e s e v e r a l n u c leo n s o u ts id e o f

th e c lo s e d s h e l l . T h u s , th e S in g le P a r t i c le M odel (SPM)

Page 18: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

11

a t t r i b u t e s th e lo w -e n e rg y p r o p e r t ie s o f n u c le i to a few

" a c t iv e " p a r t ic le s o u ts id e o f th e c lo s e d , t i g h t l y bound,

" in e r t " co re o f th e s h e l l m o d e l. I t is th e SPM w hich is

commonly r e f e r r e d to in th e l i t e r a t u r e as th e s h e l l m ode l.

T h a t th e n u c leu s cannot be a c c u ra te ly d e s c r ib e d s o le ly

in te_-ms o f In d e p e n d e n t p a r t ic le s m oving in s h e l l m odel

e ig e n - o r b i t s seems r a t h e r c le a r . As d is c u s s e d e a r l i e r , th e

a c tu a l n u c le o n -n u c le o n in t e r a c t io n w i t h in th e n u c leu s is

c o n s id e re d to c o n s is t o f two p a r t s . The f i r s t g iv e s r i s e to

th e s h e l l m odel and re p re s e n ts th e a v erag e e f f e c t on a s in g le

n u c leo n produced by a l l o th e r p a r t ic le s in th e n u c le u s . The

seco n d , known as th e " e f f e c t iv e in t e r a c t io n " is re s p o n s ib le

f o r th e rem o va l o f th e h ig h o r ie n t a t io n a l degeneracy o f

nu cleo n s w ith th e same s e t o f quantum numbers ( n ,< £ , / ) . I t

i s a p p l ie d o n ly betw een p a ir s o f a c t iv e p a r t i c l e s ; i t must

be s tro n g enough to l i f t th e degeneracy and y e t n o t so s tro n g

t h a t j ceases to be a good quantum num ber.

V a r io u s a lg e b r a ic form s have been used f o r th e c e n t r a l

p a r t o f th e e f f e c t i v e in t e r a c t io n in m odel c a lc u la t io n s .

Some o f th e s e in c lu d e :

V - { - Vo K < K n (s q u a re w e l l )0 K>fin

V = -V c e x p ( - * 2A 2 ) (G a u s s ia n )

V = _ V 0 e x p ( - * A n )

* A „(Y u k a w a ).

Page 19: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The 6- i n t e r a c t i o n , s u r fa c e d e l t a i n t e r a c t io n , p a i r in g and

q u ad ru p o le fo rc e s have a ls o been e x te n s iv e ly em ployed in more

s o p h is t ic a te d s tu d ie s . These re p re s e n t a v a r ie t y o f shapes

and ra n g e s , and y e t g iv e q u ite s im i la r r e s u l t s . T h is len d s

s u p p o rt to th e b e l i e f t h a t a t r u e u n d e rs ta n d in g o f n u c le a r

s t r u c tu r e does n o t depend on th e know ledge o f th e e x a c t

f u n c t io n a l fo rm o f th e In t e r a c t io n , b u t r a th e r on i t s g e n e ra l

p r o p e r t ie s o n ly .

c . C o l le c t iv e Models

The fo r m u la t io n o f th e s h e l l m odel d isc u s s e d up to t h is

p o in t assumes a s p a t i a l l y is o t r o p ic p o t e n t i a l . H ow ever, i t

has been found t h a t n u c le i in th e mass re g io n s A^25> 150<A <190,

and A<222 have la r g e s t a t i c d e fo rm a tio n s — th e y e x h ib i t la r g e

e l e c t r i c q u ad ru p o le moments and n o n -s p h e r ic a l shapes . I f th e

s im p le s h e l l m odel wave fu n c t io n s a re used to c a lc u la te m a tr ix

e le m en ts o f th e q u ad ru p o le moment, m ag n e tic moment, t r a n s i t io n

p r o b a b i l i t i e s , e t c . in th e s e r e g io n s , th e r e s u l t s d is a g re e

w ith e x p e r im e n t, o f te n by a f a c t o r o f as much as te n o r m o re . 12

A n a ly s is o f th e s p e c tra o f th e s e n u c le i in d ic a te s t h a t

th e shape o f th e n u c leu s may g e n e r a l ly be assumed to be n o n -

s p h e r ic a l , b u t a x i a l l y s y m m e tric . These n o n -s p h e r ic a l shapes

may be e n v is io n e d as a r is in g as a r e s u l t o f th e opposing te n ­

d e n c ie s o f th e e x t r a -c o r e nu cleo ns to p o la r iz e th e n u c le a r

co re ( t h is is due to th e lo n g range p a r t o f th e n u c le o n -n u c le o n

i n t e r a c t i o n ) , and o f th e co re i t s e l f to r e s i s t th e s e fo rc e s

and to m a in ta in s p h e r ic i t y (due to th e s h o r t range p a r t ) . 8

12

Page 20: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The q u ad ru p o le moment and t r a n s i t io n a m p litu d e s a r e , th e r e ­

f o r e , th e r e s u l t o f c o n t r ib u t io n s n o t o n ly from a few p a r t i c l e s ,

b u t r a th e r fro m th e e n t i r e n u c le u s . The d e t a i ls o f t h is m odel

w ere f i r s t d eve lo p ed by Bohr and M o tte ls o n 13 in th e 19 50 s .

The n u c leu s in t h is m odel is c o n s id e re d as a co re and e x t r a ­

co re n u c le o n s . The c o r e , f o r n u c le i f a r from m agic num bers,

i s n o t t h a t o f th e s h e l l m odel— i t c o n ta in s many more n u c le o n s .

The co re is t r e a t e d m a c ro s c o p ic a lly as a deform ed drop o f

n u c le a r m a tte r w h ich in t e r a c t s w ith th e e x t r a -c o r e n u cleo n s

on a m ic ro s c o p ic b a s is ( v . A ppend ix A - I I ) .

d . U n i f ie d Models

T h ere is no a pn.i.onL reaso n why th e e f f e c t i v e i n t e r ­

a c t io n sh o u ld n o t m ix s ta te s w ith d i f f e r e n t v a lu e s ( n , £ , / ) .

In d e e d , much p ro g re s s has been made to w ard u n d e rs ta n d in g

n u c le a r s t r u c tu r e by r e la x in g t h is assu m p tio n . The n u c le a r

p o t e n t i a l i s no lo n g e r assumed s p h e r ic a l , and th e d is t o r t io n

w h ich y ie ld s minimum en erg y is ta k e n as th e e q u i l ib r iu m de­

fo r m a t io n . Two s p e c i f ic m odels f a l l i n g in t o t h is c a te g o ry

a re th e N ils s o n and H a r tre e -F o c k m odels .

S .G . N i ls s o n 14 c a lc u la te d s in g le p a r t i c l e s ta te s o f an

a x i a l l y sym m etric s p h e ro id a l harm onic o s c i l l a t o r p o t e n t i a l ,

c o n s id e r in g a d i s t o r t i o n o f th e p o t e n t ia l up to th e q u ad ru ­

p o le te rm o n ly , and in c lu d e d a f l a t t e n i n g e f f e c t f o r h ig h

v a lu e s o f o r b i t a l a n g u la r momentum. The wave fu n c t io n s w ere\expanded on th e s e t o f Is o t r o p ic o s c i l l a t o r fu n c t io n s . T h is

le d to th e s u c c e s s fu l c o r r e la t io n o f a la r g e f r a c t i o n o f th e

13

Page 21: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

n u c le a r d a ta known a t t h a t t im e . 15 N ew ton16 ex ten d ed t h is

w ork to a c o n s id e ra t io n o f n o n - a x ia l ly sym m etric n u c le i , and

more r e c e n t ly B. N i ls s o n 17 in c lu d e d h exad ecu p o le d is t o r t io n s

w hich a re in d ic a te d e m p ir ic a l ly fro m a n a ly s is o f in e l a s t i c

a s c a t t e r in g d a t a 1 8 * 1 9 .

In th e H a r tre e -F o c k m o d e l, f i r s t a p p l ie d to n u c le a r

c a lc u la t io n s by K e ls o n 2 0 , each n u c le o n is assumed to move in

a deform ed p o t e n t i a l w e l l a r is in g s e l f - c o n s is t e n t ly fro m i t s

tw o -b ody in t e r a c t io n s w ith a l l o th e r n u c le o n s , w ith th e

r e s t r i c t i o n t h a t th e r e e x is t some " m a th e m a tic a l" s t a te ( th e

H a r tre e -F o c k s t a t e ) f o r w h ich th e H a m ilto n ia n o f th e system

i s a minimum. A deform ed s i n g le - p a r t i c le b a s is , w h ich may

be expanded on th e u s u a l s h e l l m odel b a s is , is g e n e ra te d .

The m ain d i f f e r e n c e betw een th e s e two m odels Is th e em ploy­

ment o f n o n - lo c a l p o t e n t ia ls in th e H a r tre e -F o c k m o d e l. T h is

a llo w s f o r th e tre a tm e n t o f th e n u c leu s as a system o f non­

in t e r a c t in g p a r t i c le s in th e deform ed b a s is , w ith th e a t te n d ­

a n t s im p le S la t e r d e te rm in a n ta l wave fu n c t io n s .

N u c le i in th e f i r s t h a l f o f th e 2 6 - 1 d s h e l l ap p e a r to

d is p la y r o t a t i o n a l p r o p e r t ie s c lo s e ly r e la t e d to deform ed

shapes o f th e n u c le u s . H a r tre e -F o c k c a lc u la t io n s f o r th e

ev en -e v e n N=Z n u c le i in t h is s h e l l g e n e ra te q u a s i - r o t a t io n a l

band s t r u c tu r e s whose sp ac in g s a re s y s te m a t ic a l ly s m a lle r

th a n th o se o f th e e x p e r im e n ta l s p e c t r a . As a consequence o f

u s in g n o n - lo c a l p o t e n t i a ls , an energy gap a r is e s in th e

deform ed H a r tre e -F o c k p a r t i c l e s p ec tru m . I f t h is gap is

la r g e H a r tre e -F o c k th e o ry sh o u ld re p re s e n t a good ap p ro x im a­

t io n to th e t r u e s i t u a t io n . I f , on th e o th e r h an d , t h is gap

14

Page 22: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

i s s m a l l , i t is e x p e c te d t h a t p a r t ic le s w ould be a b le to

s c a t t e r ac ro ss i t , and th e r e fo r e t h a t n - p a r t ic le / n - h o l e s ta te s

w ould m ix a p p re c ia b ly w ith th e q u a s i - r o t a t io n a l band p r o je c te d

fro m th e H a r tre e -F o c k s t a t e . T y p ic a l en erg y gaps f o r th e

26 - 1 d s h e l l n u c le i a re c a lc u la te d to be o f th e o rd e r 6 - 8 MeV,

as compared to gaps o f th e o rd e r 18 MeV in th e 1p s h e l l .

P a r t ic le - h o l e s ta te s sh o u ld th e r e fo r e re p re s e n t v a l id adm ix­

tu r e s to th e H a r tre e -F o c k s ta te in th e 2 6 - 1 d s h e l l .

3 . A n g u la r Momentum P r o je c t io n

The o r ig in a l p rob lem fa c in g n u c le a r s t r u c tu r e th e o r is t s

was to e x p la in th e p r o p e r t ie s o f n u c le i as a consequence o f

th e p resen ce o f A n u c le o n s . T h is fo rm id a b le p rob lem le d to

th e developm ent o f th e m odels d isc u s s e d a b o v e , w ith th e r e s u l t

t h a t i t i s no lo n g e r n e c e ss a ry to work in th e space o f A

n u c le o n s , b u t r a t h e r o n ly in th e space o f th e a c t iv e n u cleo n s

o u ts id e o f an i n e r t c o r e .+ But even t h is becomes to o p r o d i­

g io u s a p ro b lem f o r more th a n a few a c t iv e nu cleo ns s in c e th e

number o f m u l t i - p a r t i c l e s ta te s in c re a s e s v e ry r a p id ly w ith

e i t h e r th e number o f p a r t ic le s o r o s c i l l a t o r quantum num ber.

C o n v e n t io n a lly , th e a n g u la r momentum s t r u c tu r e o f a

com posite system is s tu d ie d by v e c to r c o u p lin g th e a n g u la r

momenta o f th e in d iv id u a l members. F o r m u l t i - p a r t i c l e system s

th e c o n s tr u c t io n o f e ig e n fu n c t io n s o f th e a n g u la r momentum

o p e ra to r is r a t h e r d i f f i c u l t . In d e e d , th e method becomes

+I t som etim es becomes n e cessary to c o n s id e r v a r io u s e x c i ­

t a t io n modes o f th e co re a n d /o r in t e r a c t io n s o f th e core w ith th e e x t r a -c o r e p a r t i c l e s .

15

Page 23: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

16

c o m p lic a te d even f o r th re e p a r t i c l e s , s in c e th e r e is no un ique

way o f c a r r y in g o u t th e c o u p lin g . T h is p rob lem has been in v e s ­

t ig a t e d by s e v e r a l a u th o rs ; p a r t i c u l a r l y e x te n s iv e work has

been c a r r ie d o u t by W ig n e r21 u s in g group t h e o r e t ic a l te c h n iq u e s .

Lo w din 22 d eve lo p ed an a n a ly t ic method f o r a to m ic p h y s ic s

"w hich c o n s id e rs th e com posite system as an e n t i t y to w n ich

th e v a r io u s components c o n tr ib u te in an e q u iv a le n t ly and n o t

n e c e s s a r i ly in an o rd e re d w ay"2 3 . The e s s e n t ia l p rem ise is

t h a t an a r b i t r a r y fu n c t io n f o r th e t o t a l system must be r e ­

s o lv a b le in a u n ique way in t o o rth o g o n a l components o f sharp

a n g u la r momentum. Each o f th e s e may be fo u n d , in p r i n c i p l e ,

by means o f a p r o je c t io n o p e ra to r w h ich a n n ih i la t e s a l l b u t

th e s e le c te d com ponent, w h ich rem ain s unchanged. The em­

p loym ent o f p r o je c t io n o p e ra to rs c o m p le te ly o b v ia te s th e

need to c o n s tru c t s ta te s o f good a n g u la r momentum, w h ich is

e x a c t ly th e s im p l i f i c a t io n n e c ess ary in d e a lin g w ith m u l t i ­

p a r t i c l e system s.

4 . M o t iv a t io n f o r S tu d ie s

M ic ro s c o p ic and m acroscop ic m odels re p re s e n t o p p o s ite

avenues o f approach to th e problem s o f n u c le a r s t r u c t u r e .

Each g iv e s r e fe r e n c e to e s s e n t ia l c h a r a c t e r is t ic s ob served

e x p e r im e n ta l ly . L o g ic a l ly , any good m odel must In c lu d e

a s p e c ts o f b o th s im u lta n e o u s ly . C o l le c t iv e m odels t y p i c a l l y

d isp en se w ith th e m ic ro s c o p ic p ic t u r e o f th e n u c le u s . The

d eg rees o f freed om o f th e in d iv id u a l nu c leo ns a re re p la c e d

by a few c o l l e c t i v e c o o rd in a te s w h ich a r e , in th e o r y , d e r iv a b le

Page 24: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

from th e p a r t i c l e c o o r d in a te s . A b a s ic assu m p tion is t h a t

o n ly a few p a r t ic le - c o n f ig u r a t io n s a re im p o rta n t in th e m ic ro ­

s c o p ic t r e a tm e n t .

The m o t iv a t io n f o r th e work re p o r te d h e r e in is th e d e s ir e

to u n d e rs ta n d th e r e l a t i o n betw een th e two c o n c e p tu a l m o d e ls ,

i . e . , th e deve lopm ent o f c o l l e c t i v i t y , in p a r t i c u l a r r o t a ­

t io n a l m o tio n s , w i t h in th e fram ew ork o f an i n d i v i d u a l - p a r t i c l e

m o d el, and i n d i v i d u a l - p a r t i c l e a s p e c ts w i t h in th e fram ew ork o f

th e c o l l e c t i v e m ode l. In p a r t i c u l a r , we w ould l i k e to answ er

th e fo l lo w in g q u e s tio n s : ( i ) In w hat way a re c o l l e c t i v e

m otio ns d e s c r ib a b le in term s o f th e s im p le g ross fe a tu re s o f

th e e f f e c t i v e n u c le o n -n u c le o n in t e r a c t io n ? ( i i . ) How a re we

to r ig o r o u s ly u n d e rs ta n d th e shape t r a n s i t io n s w i t h in a s h e l l

as a consequence o f th e c o m p e tit io n betw een th e s h o r t and

lo n g ran g e components o f th e e f f e c t i v e in t e r a c t io n ? ( i i i ) Does

th e lo n g ran g e p a r t o f th e e f f e c t i v e In t e r a c t io n b r in g ab o u t

tem p o ra ry s p h e r ic i t y a s s o c ia te d w ith th e change in s ig n o f

th e q u ad ru p o le moment in th e m id d le o f th e s h e l l , o r is t h is

caused by th e s h o r t range in t e r a c t io n ? ( i v ) Can c o l l e c t i v e

m odels make any p r e d ic t io n s abou t in d iv id u a l p a r t i c l e m otions?

(v ) Can we g iv e an e x p la n a t io n w i t h in th e fram ew ork o f an

i n d i v i d u a l - p a r t i c l e m odel f o r th e ob served d is t o r t io n s o f

r o t a t io n a l bands a t t h e i r h ig h e r a n g u la r momentum s ta te s ?

( v i ) What is th e e x te n t o f th e p a r t i c le - h o l e a d m ix tu re s to

th e H a r tre e -F o c k q u a s i - r o t a t io n a l bands in th e 2 4 - Id. s h e l l

n u c le i? ( v i i ) A re th e a d m ix tu re s s u f f i c i e n t to e x p la in th e

d is c re p a n c ie s betw een c a lc u la te d and e x p e r im e n ta l s p e c tra ?

17

Page 25: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

18

( v i i i ) Are p a r t i c le - h o l e s ta te s c a p a b le o f ,e x p la in in g th e

e x c i te d s ta te s above th e q u a s i - r o t a t io n a l band p r o je c te d

fro m th e H a r tre e -F o c k s ta te ? ( i x ) I s H a r tre e -F o c k a good

a p p ro x im a tio n in t h is mass re g io n ? A l l o f th e s e q u e s tio n s

c o n c e rn in g th e in t e r r e la t io n s h ip betw een m acroscop ic and

m ic ro s c o p ic m odels o f n u c le a r s t r u c tu r e may be answ ered

u s in g th e p r o je c t io n fo rm a lis m d is c u s s e d e a r l i e r to d e r iv e

th e p r o p e r t ie s o f e ig e n s ta te s o f th e n u c le a r sys tem , and

th u s to exam ine th e em ergence o f c o l l e c t i v e b e h a v io r from

an i n d i v i d u a l - p a r t i c l e d e s c r ip t io n o f th e n u c le u s .

5. Scope of Present InvestigationsThe purpose o f p r o je c t io n c a lc u la t io n s is to o b ta in

p r o p e r t ie s o f e ig e n s ta te s o f p a r t i c u l a r symmetry o p e ra to rs

w ith o u t e x p l i c i t know ledge o f th e s t r u c tu r e o f th o s e s t a t e s .

K e ls o n 21* has o u t l in e d t h is ty p e o f p r o je c t io n fo rm a lis m as

i t may be a p p l ie d to n u c le a r s t r u c tu r e c a lc u la t io n s and has

su g g ested v a r io u s ty p e s o f prob lem s to w h ich i t may be a p p l ie d .

The fo rm a lis m o f p r o je c t io n te c h n iq u e s w i l l be d e ve lo p ed in

C h a p te r I I . I t w i l l be shown how p r o je c t io n may be accom­

p l is h e d u s in g e i t h e r f i n i t e r o t a t io n o r i n f i n i t e s i m a l r o t a t io n

o p e r a to r m ethods. F i n i t e r o ta t io n s w i l l be d isc u s s e d b r i e f l y

i n th e f i r s t c h a p te r , and from th e r e on o n ly I n f i n i t e s i m a l

r o t a t io n o p e ra to r p r o je c t io n s w i l l be t r e a t e d . Methods w i l l

be d e v e lo p ed f o r h a n d lin g p r o je c t io n s from any number o f s t a t e s ,

r a t h e r th a n from a s in g le s t a te as is u s u a lly th e c a se . I t

th e n becomes most c o n v e n ie n t to p e rfo rm th e c a lc u la t io n s In

Page 26: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

19

bases h a v in g n o n -u n it m e t r ic s . R e fe re n c e is f i n a l l y g iv e n

to o rth o n o rm a l bases by th e in t r o d u c t io n o f th e Schm idt

o r th o n o r m a liz a t io n p ro c e d u re .

I n C h a p te r I I I th e p r o je c t io n te c h n iq u e s d isc u s s e d

and d e v e lo p ed in th e p re v io u s c h a p te r a re a p p lie d to system s

o f n e u tro n s r e s t r i c t e d to a s in g le a n g u la r momentum s h e l l .

The p a r t i c l e a n g u la r momentum spans th e range 5 /2 < /< 1 5 /2 ,

and c o n s id e ra t io n is g iv e n to n u c leo n numbers fro m two to

m id - s h e l l , th e f i l l i n g o f th e l a t t e r h a l f o f th e s h e l l b e in g

sym m etric w ith t h a t o f th e f i r s t h a l f f o r a s i n g l e - / s h e l l . ^

V a ry in g p a r t i c l e a n g u la r momentum and n u c leo n num ber, a s tu d y

i s made o f th e developm ent o f c o l l e c t i v i t y a r is in g from a

s im p le p h en o m en o lo g ic a l H a m ilto n ia n c o n ta in in g s h o r t and lo n g

range com ponents. A p u re p a i r in g in t e r a c t io n is f i r s t

em ployed in o rd e r to o b ta in th e s e n io r i t y co m p o s itio n s o f

th e e ig e n s ta te s o f th e above H a m ilto n ia n .

I f th e n u c le a r system is c o n s tru c te d such t h a t M=£ m .,i 1

where th e a re p r o je c t io n s o f in d iv id u a l n u c leo n a n g u la r

momenta o n to th e a x is o f sym m etry, and M is th e p r o je c t io n

o f th e t o t a l a n g u la r momentum, th e n th e p r o je c t io n m ethod f o r

th e system ta k e s on a p a r t i c u l a r l y e le g a n t form w h ich u t i l i z e s

th e e x p a n s io n o f c e r t a in o p e ra to rs in a p o ly n o m ia l e x p re s s io n .

In p a r t i c u l a r , f o r th e s p e c ia l case o f M = ^n+^p* where is

th e p r o je c t io n f o r th e n e u tro n s and Mp t h a t f o r th e p ro to n s ,

u t i l i z i n g th e b in o m ia l theorem o b ta in s a p r o je c t io n o p e ra to r

ex p an s io n w h ich is e q u iv a le n t in th e two c o n s t i tu e n ts . T h is

^ We n o te t h a t th e s p in - o r b i t fo rc e in tro d u c e s an assym etry w ith re s p e c t to th e m id d le o f th e s h e l l ( c f . s e c t io n I V . 4) .

Page 27: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

20

te c h n iq u e p ro ves to be e x tre m e ly u s e fu l .

In C h a p te r IV th e s e p o ly n o m ia l p r o je c t io n te c h n iq u e s

a re a p p l ie d to th e c a lc u la t io n o f p a r t i c le - h o l e e x c i t a t io n s

o f th e H a r tre e -F o c k s ta te s in e v en -e v e n N=Z n u c le i c a lc u ­

la t e d e a r l i e r by R ip k a 2 5 , in an a tte m p t to e x p la in th e sys­

te m a t ic d is c re p a n c ie s d isc u s s e d e a r l i e r betw een th e m odel

c a lc u la t io n s and th e e x p e r im e n ta l e x c i t a t io n s p e c tr a . I t

i s a ls o e x p e c te d t h a t some o f th e h ig h e r e x c i t a t io n s ta te s

w i l l be found to be p re d o m in a n tly based on p a r t ic le - h o l e

c o n f ig u r a t io n s . The need to p r o je c t sharp is o s p in s ta te s

s im u lta n e o u s ly w ith a n g u la r momentum s ta te s w i l l be o b v ia te d

by th e em ploym ent o f s im p le c o m b in a tio n s o f S la t e r d e t e r -

m in a n ta l s ta te s w hich a lr e a d y have sharp is o s p in .

As d is c u s s e d a b o ve , th e aim o f t h is w ork is to c l a r i f y

th e com plem entary r e la t io n s h ip betw een m acroscop ic and m ic ro ­

s c o p ic m odels o f n u c le a r s t r u c t u r e . By th e p erfo rm an ce o f

d e t a i le d m ic ro s c o p ic c a lc u la t io n s , we w i l l d em o n stra te and

e lu c id a t e how a system o f nu c leo ns may undergo b e h a v io r w h ich

i s t y p i c a l l y d e s c r ib e d by c o l l e c t i v e p a ra m e te rs . We w i l l

th u s show t h a t th e o r ig in s o f c o l l e c t i v e m otio ns in n u c le i

may be u n d e rs to o d from fu n d a m e n ta l m ic ro s c o p ic many-body

th e o r y .

The bases f o r p r o je c t io n c a lc u la t io n s from th e p a r t i c l e -

h o le e x c i t a t io n s o f H a r tre e -F o c k s ta te s a re r a th e r s m a ll ,

c o n s is t in g o f o n ly a few s t a t e s , in c o n tr a s t to th e ( / ) w

c a lc u la t io n s o f C h a p te r I I I in w h ich th e f u l l H i lb e r t s p a c e ,

d e r iv e d from th e c o u p lin g o f n p a r t i c l e s , i s u sed . The te c h -

Page 28: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

21

n iq u e s f o r h a n d lin g th e s e v a r ia b le s iz e bases a re d e ve lo p ed

in th e fo l lo w in g c h a p te r .

Page 29: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

22

CHAPTER I I

PROJECTION TECHNIQUES

1 . P r e l im in a r y D is c u s s io n

A n u c le a r i n t r i n s i c s ta te <f>, w i t h in th e c o n te x t o f t h is

p r e s e n ta t io n , i s an i n d i v i d u a l - p a r t i c l e m odel s ta te w h ich is

s im p le and easy to w ork w i t h , and y e t c o n ta in s a la r g e amount

o f in fo r m a t io n ab o u t p r o p e r t ie s o f th e n u c leu s in th e lo w -

en erg y re g io n o f e x c i t a t i o n . I t i s n o t an e ig e n s ta te o f th e

H a m ilto n ia n , b u t r a th e r a m a th e m a tic a l c o n s tr u c t , o u t o f

w hich th e p h y s ic a l s ta te s o f th e system may be e x t r a c te d .

I t may e i t h e r be guessed a t , i . e . , th e b a s ic assu m p tion o f a

m o d e l, o r be a d e r iv e d f u n c t io n , e . g . , th e H a r tre e -F o c k

s t a te ( v . C h a p te r I V ) . P r o je c t io n o p e ra to r te c h n iq u e s a re

used to e x t r a c t th e d e s ir e d in fo r m a t io n from th e s e i n t r i n s i c

s t a t e s .

A b r i e f re v ie w o f th e b a s ic p r o p e r t ie s o f a n g u la r

momentum o f im p o rt to th e developm ent o f p r o je c t io n o p e ra to rs +

f o l lo w s .

A g e n e ra l a n g u la r momentum if = m easured inx y z

u n its o f H may be d e f in e d by th e com m utation r e l a t i o n ifxif = i i f ,

o r c y c l ic p e rm u ta tio n s o f The assu m p tion o fx y y x »

th e is o t r o p y o f space r e q u ir e s t h a t any H a m ilto n ia n v a l id in

n u c le a r p h y s ic s be in v a r ia n t under s p a t ia l r o t a t io n s . I f

deno tes th e g e n e ra to r o f r o t a t io n s abou t th e x ^ - a x is , t h is

^ A l l a n g u la r o p e ra to rs d isc u s s e d fo l lo w th e d e f in i t io n s and phase c o n v e n tio n s o f Rose2 6 .

Page 30: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

23

- i j , e i j . e i j . e i j . ee He = H o r e H - He = 0 .

E xpand ing th e e x p o n e n tia ls in power s e r ie s and s e t t in g each

power o f 0 I d e n t i c a l l y e q u a l to ze ro shows t h a t H commutes

w ith any power o f A s im p le c a lc u la t io n d em o n s tra tes t h a t

J 2 a ls o commutes w ith any o f th e components o f J . From th e

d e f i n i t i o n o f a n g u la r momentum a b o v e , i t is c le a r t h a t no two

components commute. Hence ? 2 and any component o f ? may be

chosen as commuting o b s e rv a b le s . J is u s u a lly s e le c te d asz

t h is second o p e r a to r . The o th e r two com ponents, J and J ,x y

may be r e p la c e d by t h e i r h e r m it ia n c o m b in a tio n s , g e n e r a l ly

r e f e r r e d to as r a is in g (+ ) and lo w e r in g ( - ) o p e ra to rs :

J . = J ± iJ . I t i s e a s i ly v e r i f i e d t h a t J „ J + = J . ( J ± 1 ) , z x y z - - z

whence t h e i r names. D i l i g e n t a p p l ic a t io n o f th e s e o p e ra to rs

to e ig e n fu n c t io n s o f a n g u la r momentum j and z - p r o je c t io n m,

w i l l v e r i f y th e e ig e n v a lu e r e la t io n s

- mv *

where j may have in t e g e r o r h a l f in t e g e r v a lu e s g r e a t e r th a n

o r e q u a l to z e r o ; m is in t e g e r o r h a l f in t e g e r as is / , and

ranges

The p r o je c t io n approach may be u n d ers to o d by c o n s id e r in g

a m any-body H a m ilto n ia n H w h ich commutes w ith a l l o f th e

g e n e ra to rs o f a group G .21* The e ig e n s ta te s o f H may be c la s ­

s i f i e d by th e r e p r e s e n ta t io n s o f G; th e y may be grouped in t o

invariance may be written mathematically as

Page 31: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

r e p r e s e n ta t io n s c h a r a c te r iz e d by th e e ig e n v a lu e s o f th e

C a s im ir o p e ra to rs o f G. W ith in each r e p r e s e n ta t io n , a com­

p le t e s e t o f o p e ra to rs is d ia g o n a liz e d and th e e ig e n v a lu e s

a re used to c h a r a c te r iz e th e c o rre s p o n d in g s t a t e s . F o r

ex am p le , when th e group is S I^ , th e C a s im ir o p e ra to r is J 2 ,

and th e o p e r a to r w h ich is d ia g o n a liz e d w i t h in each re p re s e n ­

t a t io n is J z .

The i n t r i n s i c s ta te s c o n s id e re d h e re a re assumed to be

sym m etric ab o u t th e q u a n t iz a t io n a x is , i . e . , e ig e n s ta te s o f

J _ . They a r e , h o w ever, g e n e r a l ly n o t e ig e n s ta te s o f. th e

a n g u la r momentum o p e ra to r J 2 b u t r a th e r a l i n e a r s u p e r p o s it io n

o f s ta te s w ith d i f f e r e n t a n g u la r momenta. A p r o je c t io n o p e ra ­

t o r P7 , w h ich e x t r a c ts th e component P7 <J> h a v in g a n g u la r

momentum J , i s fo r m a l ly in tro d u c e d . The e x p l i c i t fo rm o f

PJ<J> i s , in g e n e r a l , v e ry c o m p lic a te d in com parison to th e

i n t r i n s i c s t a te i t s e l f . The u s e fu ln e s s o f th e p r o je c t io n

o p e ra to r te c h n iq u e l i e s in th e f a c t t h a t th e e x p l i c i t form

i s n e v e r n eed ed , s in c e a l l m a tr ix e lem en ts o f p h y s ic a l ob­

s e rv a b le s may be c a lc u la te d u s in g th e i m p l i c i t fo rm P <f».

T h e r e fo r e , i t i s n o t a t a l l n e c e s s a ry to a c t u a l ly c o n s tru c t

wave fu n c t io n s o f good J .

A p a r t i c u l a r l y s im p le form f o r th e p r o je c t io n o p e ra to r

may be o b ta in e d by o b s e rv in g t h a t th e e ig e n v a lu e r e l a t i o n fo r

th e o p e r a to r J 2 may be w r i t t e n in th e form

[ J 2 - J ( J + 7 ) ] | J , M , a > = 0 ,

where | J , M , a > is a n o rm a liz e d m u l t i - p a r t i c l e e ig e n s ta te o f

24

Page 32: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

b o th ? 2 and J , w ith e ig e n v a lu e s J ( J + 7 ) and M, r e s p e c t iv e ly . z

T h is e q u a t io n im p lie s t h a t th e s im u lta n e o u s e ig e n s ta te | J , M , a >

p o s s ib le to e x t r a c t a s p e c i f ic a n g u la r momentum component from

an i n t r i n s i c s ta te by a n n ih i l a t in g a l l o th e r com ponents. T h is

may be acco m p lish ed u s in g th e p ro d u c t o p e ra to r

The n u m e ra to r is a p ro d u c t o f th e a n n ih i la t io n o p e ra to rs

d e f in e d a b o v e , o v e r a l l v a lu e s o f a n g u la r momentum e x c e p t

t h a t o f th e d e s ire d com ponent. The d en o m in a to r i s s im p ly

a n o r m a liz a t io n te rm w h ich g iv e s th e v a lu e u n ity when

a p p l ie d to th e d e s ire d com ponent.

U t i l i z i n g an e x p l i c i t fo rm o f th e p r o je c t io n o p e ra to r

f o r b o th th e t o t a l a n g u la r momentum and i t s p r o je c t io n on to

th e a x is o f q u a n t iz a t io n :

where | J , M , a > is a co m p le te o rth o n o rm a l s e t o f e ig e n s ta te s

Is a n n ih i la t e d by th e o p e ra to r [ J 2 - J ( J + 7 ) ] . I t I s th e r e fo r e

pJ = n ? 2 - J * ( J ' + l ). J ’ t J J {J+ 7 ) - J ' ( J ' + 7)

( I I - l )

a

o f J 2 and J , a d e n o tin g a l l o th e r quantum num bers, th e w e l l z

known p r o p e r t ie s o f p r o je c t io n o p e ra to rs a re e a s i ly demon­

s t r a t e d :

Page 33: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

26

In g e n e r a l , i t may be n e c e ss a ry to c o n s id e r s e v e r a l

d i f f e r e n t i n t r i n s i c s t a t e s . These w i l l be la b e le d by s u p e r­

s c r i p t s . The i n t r i n s i c s ta te s used in th e fo l lo w in g c a lc u ­

la t io n s a re S la t e r d e te rm in a n ts o f s in g l e - p a r t i c l e s h e l l

m odel s ta te s in th e / - / c o u p lin g schem e, i . e . , | n , £ , / , m > ,

o r l i n e a r c o m b in a tio n s o f them . The l i n e a r c o m b in a tio n s ta te s

a re n o t n e c e s s a r i ly e ig e n fu n c t io n s o f th e s i n g le - p a r t i c le

a n g u la r momentum o p e ra to r J 2 , and may, f o r exam p le , be

H a r tre e -F o c k o r N ils s o n s in g l e - p a r t i c l e wave fu n c t io n s .

The i n t r i n s i c b a s is {<}>} is a com plete s e t o f e ig e n ­

v e c to r s , a l l h a v in g th e same e ig e n v a lu e o f J . F o r an evenz

number o f p a r t i c l e s , s ta te s o f a re chosen; f o r

an odd number o f p a r t ic le s s ta te s o f M^n^ = l / 2 . W ith t h is

c h o ic e one is c e r t a in th a t a l l a n g u la r momentum components

p re s e n t can be o b ta in e d v ia th e p r o je c t io n p r o c e s s .

F o r m a lly , th e b a s is s ta te s may be decomposed in t o com­

po nents w hich a re s im u lta n e o u s e ig e n s ta te s o f J 2 and J byz

th e p r o je c t io n o p e ra to r P-7:

* ( i ) ’ j X f * ( 1 ) = 5 * a ) = I aJ i ) | J ’ M* « * ’ ( 1 ) > ( I I " 2>

w here J is some maximum v a lu e o f th e t o t a l a n g u la r t n d x

+momentum a llo w e d by th e P a u l i p r in c i p le . The a m p litu d e o f

th e n o rm a liz e d s ta te | ( i ) > in th e o r ig in a l s t a t e

is g iv e n by • I f th e s t a te is n o rm a liz e d , th e s e

+In p r i n c i p l e , th e r e need n o t be an upper l i m i t to th e angu­

l a r momentum o f th e system . T h is w i l l depend on th e p a r t i c u la r m odel b e in g em ployed . I f a s h e l l m odel is used th e r e is an up­p e r l i m i t , w h ile a hydrodynam ic m odel g e n e r a l ly does n o t have one

Page 34: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

27

a m p litu d e s a re d e f in e d to w i t h in a p h a s e , and th e sum o f

th e squares o f t h e i r a b s o lu te v a lu e s is u n i t y . I t is

im p o r ta n t to n o te t h a t th e s ta te | ( i ) > Is g e n e r a l ly

n o t o r th o g o n a l to th e s ta te | 3 ( J ) > .

P r o je c t io n may be acco m p lish ed fro m any number o f

i n t r i n s i c s t a t e s . F o r exam p le , C h a p te r I I I d e a ls w ith

p r o je c t io n s fro m a com ple te b a s is , r e s u l t in g in e x a c t ( / ) w

s p e c t r a ; C h a p te r IV d e a ls w ith p r o je c t io n s from th e H a r t r e e -

Fock s ta te and I t s p a r t i c le - h o l e e x c i t a t io n s . H ow ever, even

i f th e e x a c t p ro b lem is n o t s o lv e d , th e com plete b a s is m u st,

i n g e n e r a l , be c o n s id e re d .

2 . A n g u la r Momentum P r o je c t io n by F i n i t e R o ta t io n s

The f i r s t c a lc u la t io n a l method o f p r o je c t in g a n g u la r

momentum makes use o f th e H i l l - W h e e le r 2 7 i n t e g r a l . The

m ain co n cern is w ith s ta te s w hich fo rm a r e p r e s e n ta t io n o f

a group w h ich is th e d i r e c t p ro d u c t o f a number o f SU2

g ro u p s . H e re , th e most im p o rta n t o f th e s e a re th e SU2

a s s o c ia te d w ith a n g u la r momentum ? and th e one a s s o c ia te d

w ith is o s p in The d is c u s s io n w h ich fo l lo w s may be g e n e r­

a l i z e d e a s i ly to a s im u lta n e o u s c o n s id e ra t io n o f th e s e two

g ro u p s , o r in d e e d to m ore.

A fu n c t io n o f r o t a t io n a n g le s is o b ta in e d f o r th e

o p e r a to r un der c o n s id e r a t io n . T h is fu n c t io n must be a n a ly z e d

as a sum o f Legendre p o ly n o m ia ls ( o r , more g e n e r a l ly , o f

r o t a t io n m a tr ix e le m e n ts ) ; th e c o e f f ic ie n t s o f th e p o ly ­

n o m ia ls a re th e m a tr ix e lem en ts o f th e o p e r a to r . T h is

Page 35: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

a n a ly s is is u s u a lly p e rfo rm e d by in t e g r a t io n . The o p e ra to r

f o r f i n i t e r o ta t io n s is g iv e n b y 28

-iocJ -1 8 J - i y j R (ft) = e e y e

The r o t a t io n R is c a r r ie d o u t by th r e e s u c c e s s iv e E u le r

r o t a t io n s . The f i r s t is a r o t a t io n a a lo n g th e z - a x i s , th e

second a r o t a t io n 8 ab o u t th e y ' - a x i s , and th e t h i r d a r o t a ­

t io n y ab o u t th e z " - a x is . We n o te t h a t th e axes o f r o t a t io n

a re c o o rd in a te axes in d i f f e r e n t c o o rd in a te system s, nam ely

th e c o o rd in a te system o b ta in e d by th e p re v io u s r o t a t io n .

The r o t a t io n s may a c t u a l ly be c a r r ie d o u t in th e same c o o r­

d in a te system i f th e o rd e r o f r o t a t io n s is in v e r t e d .

The r o t a t io n m a tr ix is d e f in e d as th e m a tr ix

e le m en t o f R (ft) in th e |JMA> b a s is o f th e p re v io u s s e c t io n :

< J M A | R ( f t ) | J ' M * X * > = 5 j j » 6xA’ PMM'

o r , in v e r s e ly ,

R (ft) = 7 | , ( f t ) <JM1A| .JMM'A

S in ce th e r o t a t io n m a tr ic e s obey th e o r th o n o rm a lity

r e l a t i o n

/ dnPM1M l ( f i ) PM22M i ( n ) = ^ 7 j " 6J 1J 25MiM26M{Mi ,

7 1m u lt ip ly in g by V £ ^ (ft) and in t e g r a t in g o v e r th e E u le rJLnt Z n t

a n g le s ft o b ta in s an e x p l i c i t r e p r e s e n ta t io n o f th e p r o je c t io n

o p e r a to r :

JLYlt JLYlt 2J ' + l A

28

Page 36: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

29

? J =2J+J

Sir2

The q u a n t i t ie s o f in t e r e s t a re th e m a tr ix e lem en ts

«J>( i ) |PJ |4>( J ) > = aJ ( i ) aJ ( J ) < J , ( i ) | J , ( j ) >

and (II-4)Si j = < ^ ( 1 ) |SPJ U ( J ) > «* a J ( 1 ) a J ( J ) < J , ( i ) | s | J , ( j ) >

w here S is a s c a la r o p e r a to r . I f , f o r exam p le , S is th ei 7

H a m ilto n ia n , th e n S J is d ia g o n a liz e d a f t e r t ra n s fo rm in g to

an o rth o n o rm a l b a s is to y ie ld en erg y e ig e n v a lu e s and e ig e n ­

s ta te s o f th e system .

U s in g th e e x p l i c i t form o f th e p r o je c t io n o p e ra to r ( I I - 3 )

o b ta in s th e d e s ire d r e s u l t s :

<<j) i ) |PJ |<J> > = f d n V t u <<j>(1 ) |R(fi) |<|)( ^ >* tt2

( I I - H a )

|SPJ |<|)( J ) > = fdnV*.J u <<|>( i ) |SR(f l ) |<t>( ; } ) >Sir2 i.n t A.nt

The i n t e g r a l s , known as H i l l - W h e e le r i n t e g r a l s , a re c a lc u la te d

n u m e r ic a l ly . The n o rm a liz e d wave fu n c t io n is e a s i ly seen to

be .,, (n)R(f l ) |<l>( i ) >, ( H - 5 a )

" i n t 8tt2Nj ( i )

w here N j ( i ) is a n o r m a liz a t io n c o n s ta n t g iv e n by th e d ia g o n a l

fo rm o f th e f i r s t o f e q u a tio n s ( I I - * J a ) :

Ma ( 1 ) - tJ+1 M . «l>( i ) | R ( f i ) k ( 1 ) > • ( I I - 5 b )

A s i m i l a r , a l t e r n a t iv e approach is p o s s ib le i f th e r e is

Page 37: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

30

a n a t u r a l l i m i t to th e a n g u la r momentum to be p r o j e c t e d ,

i ‘ e *» “ * T h en » f o r each Pa i r ( i » J ) o f i n t r i n s i c

s t a t e s , th e o v e r la p o f th e i bb i n t r i n s i c s t a t e w ith a r o ta te d

i n t r i n s i c s t a t e may be c a lc u la te d f o r as many d i f f e r e n t

r o t a t io n s ftk as th e r e a re p o s s ib le d i f f e r e n t v a lu e s o f

a n g u la r momentum. These th e n fo rm th e inhomogeneous p a r t

o f th e s e t o f - l i n e a r e q u a tio n s

«J>( i ) | R( f lk ) U ( J ) > = [ p j » (f ik )<d>( i ) | PJ |4>( J ) > ( I I - 6a )J I n t i n t

w ith V m a tr ix e lem en ts as c o e f f i c ie n t s . S im i l a r l y , one

o b ta in s

«|>(i) |SR(ftk )|<J>(J)> = I PjJ M (ftk )«|.(i)|SPJ |<|>(J)>. (II-6b)

E q u a tio n s ( I I - 6a , b ) a re b o th o f th e fo rm X ® V%. The column

v e c to rs b e in g e i t h e r < < j> ^ |P "7 1 <j> o r <<|>^^ | SP"7 | <J>

f o r a l l p o s s ib le v a lu e s o f a n g u la r momentum, a re e a s i ly

o b ta in e d by in v e r t in g th e m a tr ix V:

t = P " 7Jt . (II-6c)

3 . A n g u la r Momentum P r o je c t io n w ith I n f i n i t e s i m a l

R o ta t io n O p e ra to rs

a . O r th o n o r m a liz a t io n o f M u l t i - P a r t i c l e Wave F u n c tio n s

A second p r o je c t io n p ro c e d u re was f i r s t in tro d u c e d by

Lo w din 22 f o r th e s tu d y o f a to m ic s p in o r b i t a l s . I t le a d s to

a s e t o f l i n e a r e q u a t io n s , n o t u n l ik e e q u a tio n s ( I I - 6 ) , th e

s o lu t io n s o f w h ich have been found f o r b o th s c a la r and te n s o r

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31

operators 2 3The a p p l ic a t io n o f th e r a is in g o p e r a to r J + to a s im u l­

taneous e ig e n s ta te o f J 2 and J has th e e f f e c t1 /2

J + |J ,M> = [ J (J + / ) - M ( M + I ) ] |J ,M+ 7> ,

i . e . , th e m a g n e tic quantum number is in c re a s e d by one u n i t ,

and th e s ta te is m u l t ip l i e d by th e c o e f f i c ie n t [ J (J + 1 ) - M ( M + I ) ]

S u c c e s s ive a p p l ic a t io n o f th e r a is in g o p e r a to r y tim e s y ie ld s

J +y |J ,M> = Bl / 2 ( J , M , y ) | J ,M+y> ,

where th e c o e f f ic ie n t s B ( J , M , y ) a re d e f in e d by:

B ( J , M , 0) = 1

M+y- 7B ( J , M , y ) = n [ J ( J + I ) - v ( v + 7 ) ] y+0 ( I I - 7 )

v=M /

o rb ( j , m , i i ) = U t W . U J - J H J .

I J - M - u l ! 1J+M) I

The r e s u l t o f a p p ly in g th e r a is in g o p e ra to r y tim e s to th e

s t a te <|>^^ is

i/

a T1 ) j + y |J,M-cw*C,( i )>

J.max- i

1 /2

w hich is an e ig e n s ta te o f J z w ith e ig e n v a lu e T h is

s e t o f e q u a t io n s , f o r a l l p o s s ib le v a lu e s o f y ^ , may be w r i t t e n

(1 )f o r each o f th e i n t r i n s i c s t a t e s <f> I f th e m a tr ix o f o v e r -

^ S in ce th e sum o v e r J must have a l i m i t Jmax f o r t h is m ethod to be a p p l ic a b le , y can range 0 4Vl4-7max”^ n^*

Page 39: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

laps of these states (II-8) is formed, it Is immediately seen that the raising operator must operate the same number of times y in the bra as in the ket because of orthogonality of states of different angular momentum projection:

states, the coefficients B being given by equation (II-7). The metric of the subspace of states of total angular momen turn J in the space spanned by the intrinsic basis vectors

the inhomogeneous parts of equation (II-9), labeled by in­creasing values of y, beginning with y=0. B is the coefficient matrix whose columns and rows are labeled by J and y, respec­tively; is a column vector whose components are the angular momentum components of the (i,j) metric element.

< J + y | J +y <j>( J ) >

( I I - 9 )

The result is a set of linear equations for the unknown products |P^<|> for each pair (i,j) of intrinsic

{4*} is denoted byMIj = <PJ^ (i)|PJ«l>(j)> = aji)ajJ)<J,(i)|J,(j)> . (11-10)

Equation (II-9) may now be rewritten:

J- B& for each (i,j)

where J+<j> represents a column vector whose components are

( I I - l l )

Page 40: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The inhomogeneous parts of equations (11-11) must be calculated by actually performing the J+y operations on the intrinsic determinantal states and computing the scalar pro­ducts, after which the metric is obtained using matrix algebra. The coefficients B form a triangular matrix in the upper triangle (the number of terms in the summation decreases when y increases), so that the (i,j) element of the metric may be obtained for successively smaller values of angular momentum, beginning with J=Jmax> by successive elimi­nation. For M^n^=0, V~JmCLX» there is only

<J+JBa ^ ( l ) | J+JmaS (j)> . B (Jmax,0,JmaJC) M ^ ax ,

which gives directly the value M . ^ a x . Then the equationsJ 13-Jfor V=Jmax~1 give the values MjJax » etc. This is the essential part of the projection process, in which the pro­perties of eigenstates of total angular momentum are retrieved from eigenstates of angular momentum projection onto the axis of quantization.

Having obtained the metric of the subspace of a partic­ular eigenvalue of the total angular momentum, it remains only to apply an orthonormalization procedure to obtain trans­formation matrices U"7 which, when applied to the Intrinsic basis, will yield an orthonormal basis for each eigenvalueof J? For example, a Schmidt orthonormalization process may

(k)be used, in which case the orthonormal function ¥j are given (for a real metric) by

33

Page 41: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

(k) _

34

(II-12)

( < * J ( k ) i # J ( k ) > - Y < ^ { i ) \ ^ M > z ) l / 21=1

Expanding the above,k

t

•>< (k) _ J ^ *J W)

- *j(k>S t i DW ) J i ° ^ * J« )

(11-13){ < * / * > i * _ / * > > I ( i y l m „ ^ j ) i

2, l / 2k-1 i• 1 ( 1 1=1 m=l

The transformation matrix elements are recursively obtained be equating the coefficients of the intrinsic basis. They are:

U

U

U

k,k+n

Jk,k

Jk,k-n

= 0

{ V k ) i * J ( k ) > - T ( i < M ] 2 ) }1=1 m=l

- 1 / 2)(II-14)

n k-m . T , 7

The solution is unique up to a unitary transformation.

b. Tensor OperatorsThe tensor operator is denoted by T , k being the rank

of the tensor, and q the magnetic component. The quantities of interest are the reduced matrix elements

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35

Applying the operator Tq to the states (IIr-8) obtains

Forming scalar products again with the states (II-8) yieldsi i r ,, m i J m a x J m a x i / 2

<J+% (1)|T^|J+I,4.(j)> = 6x>y+q ^ ^ B

Mi n t + V ** U i n t lv

1

The dependence on orientation can be removed by Invoking the Wigner-Eckhart Theorem21,

<J1,M1|Tk |J2,M2> = C(J2,k,J1;M2,q,Mi)<Jl||Tk ||J2> , (11-16)

where <Ji||Tk ||J2> is the reduced matrix element of Tk and is independent of orientation. All of the geometrical depen­dence Is included in the Clebsch-Gordan (CG) coefficient C.Thus,

y r*\ , /,\ ^max ^max i/2<J+ * J > = { X ,y + q I I B

V J 2 =U i n t * X U M * V

<J,,(l)||Tk ||J2,(j)> .

This set of linear equations, for » andis solved to obtain the products a l ^ a l ^ c J x ,i| |Tk | | J2,j>

1 2

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36

The inhomogeneous part poses some technical difficulty, as it is easier to solve for products of the form <J+p+q<}>^ | J+pT^<f>^ . This is accomplished by successively invoking the commutation rules of irreducible tensor operators with angular momentum operators26,

CJ+,Tq] = [k(k+l)-q(q+l)]l/2 T*+1 .

One easily obtains

<J+X*(i)|Tq|J+M4>(3)> - «x>u+qJ o <-l>m (t;) B ,/2(k>q,m)

<J+X<f>(1) |J+y-m Tq+m<J)(J)>, (11-18)

where (p) is the binomial coefficient defined by

© = HJ— . (11-19)m!(y-m)!

We note that m has a further restriction m+q<k, arising from the tensor operator in equation (11-18). Thus, to

Ifobtain these scalar products for T , it is also necessaryto work with the higher magnetic components.

Equation (II-18) is used to find the inhomogeneous partsof equations (11-17), which are then solved for the productsal^a l ^ c J , ,i | |Tk | | J,, j>. The transformation matrices (11-14)

J l J 2 2

are applied to these to obtain the reduced tensor matrix elements between orthonormal states. If, for example, T^ is the quadrupole operator, the diagonal matrix elements in the orthonormal basis are the quadrupole moments of the states, and the non-diagonal elements are related to the BE(2)s.

Page 44: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Tensors of rank k=0— scalars— are treated as a special case of the previous section. The scalar operator is denoted by S. The matrices of interest, S ’ ^ were defined by equation (II-4). The elements of these matrices may be obtained as follcws:

37

c. Scalar Operators

S * (J> ■ I S3 k * (k) ' £ Sj k j ■

where Sjk is the matrix element of S in the intrinsic basis. The raising operator applied successively to yields

II M l _ ' > /2 ( HJ + s * ■ I s J k B '

Mint*vForming scalar products with the states (II-8), as in the previous section, utilizing the fact that the scalar operator S commutes with the raising operator J+ , obtains

t (a \ / * \ ' RKIX<J+P ♦(1)|s|j»;JJ)> " t w , l SJk I

If M • y.+ U ‘tnt (11-20)

a j ^ a j ^ J ^ ^ + y , (i) | J,M^nJt+y, (k)>

or, using equation (II-4),<J+y,4,(1)|s|J+y<|»U)> = 6yp, I B(J,M^,p)SiJ

J (11-21)J , £ = B$' for each (i,J)T •

These equations have the identical structure as equations (11-11). Here represents a column vector whose components are the inhomogeneous parts of equations (11-20), labeled by

Page 45: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

increasing values of y beginning with y=0, and is a column vector whose components are the angular momentum components of the (i,J) matrix elements of the operator S in the intrinsic basis. The solutions of equations (11-21) are obtained In a manner similar to those of euqtions (11-11).

We note that instead of calculating the expectation values of S between the many pairs of states of a complicated form, generated by the Hamiltonian, operation is required only on those states which are intrinsic and of simpleform. The raising operator is, of course, a one-body operator. The only place in which a two-body operator (the Hamiltonian) may enter is the initial set of simple intrinsic states.

Applying the transformation matrix U"7, (equation (11-1*1)) to the matrix

SJ = S ’J UJgives the matrix in the orthonormal basis {U^$}. This matrix is usually diagonalized to yield eigenvalues and eigenvectors. The eigenvectors are expressed as linear combinations of the wave functions projected from the intrinsic states. The explicit form of the projected wave functions is unknown.

M. A Neutron-Proton Polynomial Projection Techniquea. IntroductionThe projection techniques discussed In the previous

sections are certainly applicable to systems of neutrons and protons if a suitable isotopic spin formalism is intro­duced. Present-day calculations are still limited to near­

38

Page 46: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

closed shell nuclei because the number of possible multi­particle states increases extremely rapidly with increasing number of neutrons and/or protons outside of a closed core.^For this reason, following a suggestion by Lowdin23, a method has been developed which greatly decreases both the number and complexity of the intrinsic states necessary for the calculation.

The part of the projection calculation which involves the determinantal multi-particle states is the calculation of the inhomogeneous parts of equations (11-11) and (11-21), i.e., scalar products of states having various angular momentum projections onto the axis of quantization, which have been generated by successive application of the raising operator to the intrinsic states. Once this has been accom­plished, It is necessary only to solve the sets (11-11) and (11-21) of linear equations by successive elimination to arrive at the desired projection results. In order to make the task practical, the basis {<(>} of the Hamiltonian operator is written as the outer product of the neutron space {a} and the proton space {&), coupled to total angular momentum pro­jection M=0,

W = [ ( « } 8 { 8 > ] m=0- ( H - 2 2 )

Since the separate neutron and proton spaces have zero over­lap, the antisymmetrization between them need not be considered, as would be necessary if t_ were not a good quantum number for the calculations. Therefore, the intrinsic states need not be

For Neon 20 there are 2498 possible determinantal states with M^O.

39

Page 47: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

totally antisymmetrized, rather the neutron and proton parts may be antisymmetrized separately.

The need to utilize a large number of states if the polynomial technique is not employed may be understood by realizing that for each neutron state it would be necessary to consider a large portion of the proton space, and vice versa. With the technique developed below, projection results may be calculated in the separate spaces and then

4*combined to yield the results for the total system.

b. Isotopic Spin ConsiderationsThe procedure is demonstrated for nuclei in which protons

and neutrons move in the same single-particle eigen-orbits.They need not, however, have the same one-body energy eigen­values. This becomes important in nuclei above mass 40, where the Coulomb potential raises the proton single particle levels significantly above the neutron levels. If this type of cal­culation is to be performed for nuclei in which the protons and neutrons do not move in the same single-particle eigen- orbits, eigenstates of isotopic spin may be obtained by successive application of the raising operator T+ in isospin space, the mathematics of which is analagous to equations (II-8) through (11-11), but which is practically very difficult to perform.

* These separate bases contain a total of only 40 possible neutron states and 40 proton states for Neon 20.

*10

Page 48: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

It is assumed that projection is to be accomplishedfrom a single determinantal state iji, such as results froma Hartree-Fock calculation.- Since this state is generallya pure T = |T | state, (where T(T+1) and Tw are the eigen- z z

values of the isotopic spin operator 'f2 and the projection operator in isospin space T ) isospin projections need not be of concern at this time. The method may be extended to projection from many states, such as partlcle-hole excita­tions of the Hartree-Fock state. This will be done in a later chapter. It is further assumed that the nucleus is even-even, although this is not necessary for the concepts which follow.

It is more convenient to write the Hamiltonian basis (11-22) as

■ {<*>} = (v> 8 {*) ® I { v B-m'} » (H-23)m'+O

where the neutron states {v} having Mn=0, and the proton states {tt} having Mp=0, are the bases for the separate problems of projection from neutron states and projection from proton states. The intrinsic state considered here contains only combinations of states from these separate bases.

c. Projection Method - NormalizationsThe intrinsic state ip may be written as a product of an

intrinsic neutron and intrinsic proton wave function. These are denoted by |v> and |ir>, respectively:

41

Page 49: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

| iJ/> = | v> | ir> .The raising operator is now applied successively to this combined intrinsic state as in section II.3a:

J+ | 9> = | «J + V> | TT> + |v>|j+7T>

J+2 |<|»> = |J+ 2v >|tt> + 2 1 J+v> | J+ir> + |v >|J+2tt>

and p . .J / I * > = 1 ( X) I J + V > I J + R> > (1 1 -2 4 )

X=0 *

where (y) is the binomial coefficient defined by equation(11-19). Forming the scalar product of the states (11-24)with themselves obtains

<J+% I J+V = I (5J)2<J+Xv|J+Xv><J+y_XTr|j+y"XTr>. (11-25) X—0

Each of the overlap expressions appearing on the right hand side may be decomposed into its separate angular momentumcomponents, analagous to equation (11-11):

Jn wax

42

<J+ V IJ+ v> = I B ( J j , 0 , X ) M 1

where

Jj-XJp

<J+y_XTr|j+y"XTT> = j B( J2 ,0 ,p-X)MP 2J 2 = li-X

Mn J * = a j aV <PJ i v | P J iv>J i J i

MpJz = a* a l <PJ 2t t |PJ 2tt> .J 2 J 2The usefulness of the polynomial technique now becomes

apparent. Rather than actually performing the J+ operations on the left hand sides of equations (11-25), these operations are carried out on the separate simpler neutron and proton

Page 50: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

states |v> and |ir>. The metrics Mn" 1 and Mp"L are calculated using equations (11-11), and are then substituted into the equations for the combined system:

< J + P < H j + y 'J» = ^ (V) 2 I B ( J 1 ,0 , X ) B ( J , , 0 , y - X ) M n J iMp J *. (11-26)A= 0 J j =A

J 2=y-X

Thus, the numberous complicated neutron-proton states are no longer required to obtain the system metrics.

d. Projection Method - EnergiesBecause electric charge is a conserved quantity, the

nuclear Hamiltonian can be divided into three parts— one involving only neutrons, one only protons, and one both neutrons and protons:

H = H + H + Hnn pp np

H|*> - I Hnn(i)|v(1)>|lt> + Hpp(i)|v>|ir(i)>

+ I + H ’ (ij)|a(1)> | 6 (3)>(II-27)i j

where, for example,

H„ n (1 ) " < v ( 1 ) lHn n lv>

Hnp(iJ) “ <»(1>’'(3)|Hnp|vi.> .

The bases (v)and {it} must contain all states of angular momen­tum projection Mn=0 and Mp=0. The states (a) (neutrons) and (B) (protons) do not have this property, but the combinationsincluded in H' have total angular momentum M=M +M =0. We np n p

43

Page 51: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

note that the states | a ^ > and | 3 ^ > differ from |v> and |ir>, respectively, by only one particle each.

Applying the raising operator successively to the states (11-27) is easily seen to be a generalization of equations (11-24):

44

- ! (> ) { Hn n I J+ X v > I J+ u_Xtt> + Hp p |J + xv > | j + » - \ >a=o

+ Hn D I V v > | j +'1- V + H- I j / v > ! ! / - % > ) .y-A,np np

Defining

HpJ2 = a 7 a 7 <PJ2ir|H |PJ2tt> J2 J2 pp,(i)

= ay a® <PJ iv|PJ ia(i)>

NpJ2 = * a ^ < P J 2ir|PJ 2 3 ^ ) >J J 2 J 2

? ( 1 1 - 2 8 )

the expectation value of the Hamiltonian in the state |J+y^> becomes

<J yi H H | J . V = I {(J)2 jBCJj.O.AWJj.O.y-A)A J , J 2

[MnJiHpJ2 + HnJlMpJ2 + I Hnp(ij)MjJlMpj2]

+(5) l (^ li j

Bi/2(J2,0,y-A)B1/2(J2,-mi ,y-A+mi)NjJ »WpJ2}

(11-29)

Page 52: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

where m^ is the magnetic quantum number of the state |c/^>.The metrics M-7 have already been calculated in separate neutron and proton spaces for equations (11-26); the Hamil­tonian matrices defined for separate bases by equation (II-4), are calculated as solutions to equations (11-21).The matrices N"7 are similar to the metrics M-7, except that the kets are not the bases {v} or {tt} but rather {a} or(3); they are obtained as solutions of the equations

Jmax<J+Xv|j+X”mka (k)> = ^ XBi/2(J,0,X)BV2(J,mk ,X-mk )NjJJ

1 1 m ( o \ J L v ( 1 1 - 3 0 )✓ t A | t A—mo n \ J v widx w+ ' + B = l B1/ 2(J ,0 ,X )B 1/ 2(J,m X-m,)wPJ

J=X

Part of the coupling of the two spaces is achieved merely by calculating two-body matrix elements Hnp and between the bases. The only part for which further calcu­lations must be performed is the solutions for the matrices N-7. These again, involve only separate basis calculations.The inhomogeneous parts of equations (11-21) for the total system are calculated using equation (11-29), and the solution by successive elimination follows immediately.

The utility of the above polynomial approach cannot be20overemphasized. The Hilbert space for Ne , for example, is

reduced from a required consideration of 2498 neutron-protonM=0 states, to one of 40 M =0 and 40 M =0 states. For the * n peven-even, N=Z nuclei, as will be treated later, consideration need not even be given to the proton states, since the matrices

45

Page 53: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

developed in that space are identical to those developed in the neutron space. These factors cut typical computational times by a factor of the order ten or more. This allows calculations to be performed in the middle of the 2 i - 1 d shell which were not possible with previous techniques.

Having developed the theory and formalism of angular momentum projection techniques, we turn now to an application of these techniques to the study of the connection between microscopic and macroscopic models of nuclear structure. In particular, in the following chapter consideration is given to simple microscopic configurations interacting through phenomenological forces which have the main characteristics of the nucleon-nucleon force within the nucleus. A study is made of the development of collective phenomena within the framework of this microscopic model.

46

Page 54: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

CHAPTER III STUDIES IN SINGLE j CONFIGURATIONS

1. IntroductionThe number of different states of a multi-particle

system increases with an increase in the possible angular momentum values of the individual particles comprising that system. Eigenstates of the Hamiltonian will, in general, be linear combinations of these states. As the number of particles, and therefore the number of degrees of freedom, is also increased, it is expected that some of the particle coordinates will find a natural grouping in collective coor­dinates, resulting in the possibility of exhibition of collec­tivity in the energy spectrum, transition, and multipole properties of the nucleus. For example, a two particle system interacting via a central potential has a wave function which may be considered as the product of a rotation function and an intrinsic function. The spectrum of such a system does not, in general, appear collective because these two modes of excitation are strongly coupled, and the energies associ­ated with them are of the same order of magnitude.

Throughout the nuclear mass table, many phenomena are observed— ground state spins, magnetic moments, excited states, magic numbers, etc.— which have natural explanation in an individual-particle model. At the same time, among the particle-like spectra are found phenomena of an undeniably collective nature, such as rotational and vibrational excita­

47

Page 55: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

tion spectra, which find natural explanation in a collective model.

As has been previously mentioned, exact shell model calculations become prohibitive in both time and required computer memory storage demands, even when considering only a few nucleons outside of a closed, inert core. For this reason, a suitable truncation of the very large shell model Hilbert space— a model space— must be chosen. It is desir­able to have a relatively simple means of control of both the particle angular momentum and the number of nucleons in the system, while maintaining the proper quantum mechanical properties of the nucleons. A model space which satisfies these requirements is that of ( j ) n- - n particles, degenerate in their single particle energies, restricted to one value of the single-particle total angular momentum /. For simplicity only neutrons will be treated.

Utilizing the projection techniques developed in the previous chapter, the emergence of collective behavior from an individual particle description of the nucleus will be examined. Studies along these lines have been carried out mainly for spinless particles.29 This represents an un­justified oversimplification of the situation. For example, the inclusion of spin and the spin-orbit force splits the

and *d3/2 -'-eve -s by approximately 5 MeV, which would otherwise be treated as degenerate. Bargmann30 introduced spin in the form of a spin-orbit force, which however, tends to destroy the L-S coupling scheme used in his calculations.

48

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49

It is desirable to consider the intrinsic spin of the nucleon explicitly. This is accomplished in the calculations reported here by the employment of the j - j coupling scheme.The deformations produced in this particular model have been investigated by Baranger31, but eigenstates of the system were not found.

The complete (/)n space is considered. Projection tech­niques are applied to generate all of the exact eigenstates of the ( j ) n system interacting through a phenomenological Hamiltonian containing varying mixtures of short and long range components. These will be shown to be in agreement with the general predictions of a collective model in which individual particles are coupled to a nuclear core having a quadrupole distortion (v. Appendix A-II). Nomura32 has used the seniority scheme to obtain approximations to the low-lying excitation spectra in this model space. This pro­cedure will be shown to be invalid by generating an exact seniority analysis of the eigenstates of the Hamiltonian.This analysis can also be used to determine the degree of pairing and therefore of sphericity of the wave functions.This point will be discussed in detail later in the chapter.

Considering the shell model, (/)n configurations may exist in the regions of very low excitation of nuclei with one closed shell and a few nucleons in or 1g9^configurations. However, past calculations have shown that such a configuration represents a poor approximation to the true situation. Therefore, no attempt will be made to match

Page 57: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

the results of the calculations reported here to experimental

data in these regions. Rather we shall concentrate, as sug­

gested above, on an attempt to elucidate the emergence of

general collectivity from this microscopic basis.

2. Pairing + Quadrupole Model

a. Introduction

Elliot33 has shown that collective static deformations

and attendant rotational excitation spectra are obtained for

nuclei far from a closed shell if the nucleons, moving in a

mixed configuration space produced by an harmonic oscillator

potential, Interact via a two-body force of angular dependence

?2 (cos 0). This force also gives rise to quadrupole vibrational

excitation spectra for nuclei with or near closed shells.

Dayman31* showed that this exhibition of collective properties

is a general characteristic of the /-/ coupling scheme arising

from interactions having slow angular dependence, such as

P2 (cos 0); it is independent of the use of harmonic oscillator

states and of the particular radial dependence of the interac­

tion; it is dependent upon the adiabatic condition that intrin­

sic excitations are much greater than rotational ones. The

low multipoles of the force, which are associated with a long

range, represent that part of the interaction where the

effects of many nucleons upon a single given nucleon are ex­

pected to contribute coherently, those contributions from

higher multipoles having a tendency to cancel because of their

dependence on the rapidly varying spherical harmonics.

50

Page 58: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

There are, however, additional interaction effects which

cannot be included in a nuclear deformed field. They may be

inferred from the following observations: (IL) Surface deforma­

tions submerge with an approach to closed shell regions.

(ILL) Even-even nuclei invariably display J=0 ground state

spins. (-ii-L) The low-energy excitation spectrum for e/en-

even nuclei is particularly simple. There is an energy gap,

corresponding to the energy required to break a J=0 pair,

below which only collective states appear. (-tv) The last

nucleon is less strongly bound in an odd-mass nucleus than

in the neighboring even-even nucleus, where it can form a

pair. These effects arise from the relatively short range

part of the two-body interaction.

In view of the fact that many nuclear phenomena can be

explained by considering the nucleon-nucleon interaction to

consist of a combination of these two simple forces— a short

rang pairing force and a long range field producing force—

a particularly simple model has evolved. Since the nucleon-

nucleon interaction is a complicated entity, a model in

which the interaction is represented by these two phenomeno­

logical components cannot be expected to yield quantitative

properties of nuclei in precise agreement with experimental

data. The model does, however, predict the main qualitative

features of the observed spectra35. In particular, it accounts

for the generally observed, gradual transitions from closed

shell spherical region to regions of static deformation, and

51

Page 59: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

it seems to work well in the Samarium region, where abrupt

shape transformations are observed.

Three types of nuclei are distinguishable by their

resistance to deformations of the quadrupole type. Starting

with a doubly closed nucleus exhibiting spherical symmetry,

the addition of extra nucleons causes the onset of deformations,

first of the (-c-c) dynamic type, and then finally of the (xXt)

static type. The rate of this transition from spherical sym­

metry to permanent distortion depends on the region of the

nuclear periodic table being considered, but the three steps

are broadly characterized by: (Z) The near-closed shell

nuclei exhibit low-lying nuclear structure (i.e., energy

levels, transition rates, moments, stripping and pickup

cross sections, etc.,) due primarily to the valence nucleon(s).

(iJ.) Adding more nucleons produces a stronger net force on

the core, resulting in a dynamic deformation and shape oscil­

lations interpretable through a vibrational excitation spectrum.

(ill) The addition of still more particles produces a perma­

nent static deformation of the core, which may exhibit rota­

tional motion. A further increase in the number of nucleons,

as the shell becomes filled, causes the situation to revert

back to (-Ac) and to {<.) above, and finally to sphericity for

the next closed shell.

Near ciosed shells the short range pairing interaction

dominates over the long range, field producing forces, resul­

ting in spherically symmetric systems. While each pair of

52

Page 60: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

53

particles is on the average spherically symmetric, the pair

will, at all times, be undergoing fluctuations in which it

is in a non-spherical configuration. If the long range

force is not too important, these fluctuations occur inco­

herently and independently, resulting in a spherical overall

system. Adding more particles to the system increases the

importance of the long range forces^, so that the fluctua­

tions of one pair will result in a time dependent non-

spherical field, inducing fluctuations in other pairs which

will be coherent with those of the first. The system thus

undergoes shape oscillations.36 With the addition of still

more particles, until the middle of the shell, the long

range force becomes still more important and its effeict

overrides that of the pairing interaction, giving rise to

statically deformed nuclear shapes.

b. The Quadrupole-Quadrupole Interaction

The central part of any two-body interaction potential

between nucleons may take the form

v l Vk (r1>rj)Pk (coS

where Pk is the Legendre polynomial and is the angle be­

tween the vectors r^ and r ^ . Expanding V k as a power series

in gives

^ The number of long range correlations in an N particle system is N(W-71/2, while the number of pairs is W/2.

Page 61: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

v = I i I vmn r i +m I y * y ( 01 »<<>1 ) r j +n ^ <e. ,4 * . ) ( I I I - l )i< J k mn y y i i j y J j

k lrwhere are expansion coefficients, y* are spherical har­

monics, and (r^,0£,$^) are the polar coordinates of the 1th

particle. At first glance such an expression appears objec­

tionable because it diverges as the radial distances grow

large. This is certainly so. However the wave functions go

to zero much more rapidly at distances large compared to a

nuclear diameter, so the divergence of the expansion is of

little consequence. It is also to be noted that negative

powers of r^ and/or r^ are not permissible because the poten­

tial would then represent an infinitely hard core, which is

not generally accepted as an effective interaction.

The low multipoles of the force are associated with the

relatively long range part of the interaction. Kugler37 has

shown that in the long-range limit any reasonable potential

contains a considerable amount of the above quadrupole-quad-

rupole interaction. If only initial and final states of the

same parity are considered, the dipole-dipole interaction

k=l term vanishes. This leaves the quadrupole-quadrupole

Interaction term k=2 as the dominant component having long

range characteristics. Elliot33 has obtained the exact solu­

tion for this term, as well as a classification scheme. It

is, however, limited to spinless particles, the coupling

scheme being associated with the group of three dimensional

unitary transformations (v. Appendix A-I ). The coupling

scheme groups together states whose L-values are just those

Page 62: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

of rotational bands cut off at some upper value of L.

That these states do, in fact, belong to a rotational band

was shown by exhibiting them as Hill-Wheeler integrals (v.

section II.2) over a single intrinsic function having a good

quantum number K, the component of angular momentum along

the intrinsic z-axis. With the above considerations, the

quadrupole-quadrupole force was chosen to represent the long

range part of the Interaction:

V a d = VQ r2 C y2( ° x ) ^ 2 ( ° 2) 30°

= VQ *i r 2 I ( - D y *J(nx) ( n i - 2 )

where V q is a strength parameter; y2(ft1) operates on particle

number 1 and y2(ft2) operates on particle number 2, these

coupled to zero angular momentum. The matrix elements of

interest are

<(n/)SJ,M.«|Vquad|(n/)2,J,M»(l> -

V Q I X ( - l ) u m m 1 y

<ym , |y2 | /m></-m»|/2y |y-m > . (III-3)

The radial integral of r2 between the shell model wave func-+

tions, being constant for a single shell , has been absorbed

into the strength parameter V q . The dependence on orientation

may be removed from equation (III-3) with the help of the

tA shell is defined here as having only one value of the

single-particle angular momentum j.

55

Page 63: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Wigner-Eckhart theorem (11-16). Since the CG coefficient

C (J,0,J;0,0) is equal to unity, writing V^uad for the re­

duced matrix element < (n/)2,J| |VqUaciI I

J i 2Vquad = VQ ^ C(/f/,J;m,-m)C(/,/,J;m',-m')

m=-/y=-2

C(/,2,/;m,y)C(/,2,/;-m,-y)</|\ y z \ | / > 2 where m'=m+y. Invoking symmetry relations of the CG coeffi

cients2 6

Vquad= VQ c (/»2,J>,P)C(j,j>J;m,,-ffl')

C(2,/,/;-y,-m*)C(/f/,J;m,-m)</||V2 ||/

The summations over the (artificial) indices m and y of the

CG coefficients may be replaced by a Racah coefficient

W (a,b,c,d; e., by means of the identity26

[ ( 2 e + n ( 2 r f + m l/2W(a,b,c,d;e,*) =

C(a,b,e;a,3)C(e,d,c;a+6,6)C(b,d,j(;8,6)C(a,)J,c;a,B+6) .

Thus TV a d - J ) V q w c y , z , j , / ; y , / ) < y 1 | y 2 j | y > 2 . . .

Noting that for identical particles, only even values of J

are allowed by the Pauli principle,

V a d - ( * / ♦ > ivQ w ( y , i , y , / ; 2 , j ) < y | | y 2 lii> 2 .

With the reduced matrix element (A-I-5)

V quad = - W r . W J + U W * ) . VQ W(/,/ ,/ ,/; 2,J)

j l j + ’ l

56

(III

Page 64: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

where again the constants have been absorbed into the strength

parameter V q , and explicit use has been made of the fact that

the single-particle states all have the same parity, given by £

(-1) , where the value of Z would depend on the oscillator

quantum number n.

57

c . The Seniority Quantum Number and the Pairing Inter­

action

Shell model wave functions | m a y be used to

characterize the states of a nucleon in a central field. The

states of a system of two non-interacting nucleons in a cen­

tral field may be characterized by the product wave functions

\nl , l l , j1, m l> \ n2, l z ,j2,m 2>. If the particles are allowed to

interact through a Hamiltonian which mixes configurations,

the individual angular momenta 7i and 7 2 are no longer con­

stants of the motion, and their projections m x and m 2 onto

the axis of quantization are, of course, no longer good

quantum numbers. Instead, the constant total angular momen­

tum of the system 7 = 7i+7z and its projection M remain as

the only good quantum numbers. If the interaction is not

too strong, the individual orbital (Z) and total (/) angular

momenta may still be approximate quantum numbers. The con­

figuration-mixing interaction will have no matrix elements

between states of different parity, i.e., (Zl+Z2 ). =

(£i+£2)i n i t i a l .

Carrying the development of the system one step further,

for a system of three interacting nucleons, the quantum num­

Page 65: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

58

bers j ly iiy S 3> J and M (suppressing now the quantum numbers

n and I) are no longer, in general, sufficient to fully de­

scribe the states. The angular momentum of, say, the first

two particles J 12 = 7 i+?2 may also be used to describe the

system. If, however, the particles are equivalent, i.e.,

/ = j V j V / 3, there is no longer meaning to choosing a particu­

lar pair of particles, and thus ? 12i°ses its physical signi­

ficance. There are then not enough quantum numbers to describe

the interacting system completely.

One possible solution to this problem was given by

Racah38. He introduced the operator Q which measures the

number of particles coupled to zero angular momentum, and

classified the states of the system such that this operator

is diagonal. Jahn39 demonstrated that for short range

forces, the energy eigenstates are nearly eigenstates of Q,

and in the limiting case of 6-forces the states of the

system are simultaneous eigenstates of the Hamiltonian,

angular momentum, and the operator Q. This is understandable

since, for a short range attractive interaction, contribu­

tions to the matrix element of the force will be greatest

when the particles are correlated in pairs with maximum

spatial symmetry and consequently antiparallel spins.

For spheroidal nuclei exhibiting the phenomenon of

"dynamic pairing" these "saturated" pairs coupled to zero

angular momentum contribute very simply to many character­

istic properties of a state; a number of such pairs may be

added to a given system of particles without changing its

Page 66: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

properties very much. It is, therefore, advantageous to

consider the number u of non-saturated particles, which

determine most of the properties of the state, plus a number

of saturated pairs. This number of non-saturated particles

u is called the "seniority number" because it gives the

smallest number of particles required for forming a state

with given properties, and thus specifies the simplest con­

figuration which contains such a state in cases where dynamic

pairing is applicable. There are, however, regions where

dynamic pairing is not applicable. For example, in the region

O s ^ ^ - 0 s ^ Z the addition of a "static" pair of nucleons

alters the properties of the nucleus considerably, so that

while Os*®^ is highly deformed, 0 s ^ Z is spherical.1*0

The concept of dynamic pairing is employed in these

calculations, not so much because consideration is being

given to nuclei where this type of interaction predominates,

but rather because it gives rise to the concept of seniority,

which will be used to determine the degree of sphericity in

the wave functions arising from the deformed field part of

the interaction. The association of pairing with sphericity

may be understood from a consideration of two particles

moving in the time-reversed orbits |/,m> and 1,1 In

such cases the particles are (classically) in close proximity

to each other two times during each period of revolution

about the nuclear core (which gives rise to the shell model

states). If these particles Interact through a strong short

range force, they are frequently scattered into different,

but still time-reversed orbits. In this way the particles,

59

Page 67: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

6o

The notation of second quantization is used here to

obtain the matrix elements of a particular short range

pairing interaction in the seniority scheme.'*2 The closed-

shell or vacuum state is denoted by |0>. The creation

operator a* is defined as that operator which produces a

particle of spin / with z-projection m when operating on the

vacuum state:

a* |0 > - |j,m>.

The corresponding annihilation operator am , of course, gives

zero when applied to the vacuum state. These fermion creation

and annihilation operators obey the anticommutation rules

{a* a.,) = <S , { A V . ) * - 0. (III-5)m m mm m m m m

The operators which create a pair of particles with spin J

and z-projection M are defined by

a jm * • (III=6a)

Since the particles being considered are identical, only

even values of angular momentum J are allowed. The associated

annihilation operator is defined as

The commutation rules for these operators may be calculated

by invoking the definitions of the operators, with the result

within only a few cycles, cover the entire angular range,and the average mass density distribution is spherical.

Page 68: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

61

+ C(/,/,J;M-y,y)y

C C / ^ J ' j y . M ' - y J a

We note that because the second term ends with an annihila­

tion operator, when the commutator is applied to the vacuum

state- this term gives no contribution. Using equation (III-7)

obtains

which gives the number of particles in the state, denoted by

N. Defining the quantity ft = /+!/2, the above commutator

becomes

Experimental data from spheroidal nuclei typically show a

depressed J=0 ground state. Other observations indicating

the presence in the true nucleon-nucleon interaction of a

pairing contribution are discussed in the introduction to

this section. We therefore chose a Hamiltonian which will

depress two particle states of zero angular momentum but

leave other states unaffected. Such an interaction is given

by

where G is a strength parameter.

In order to find the two particle spectrum, the pairing

Hamiltonian is applied to a state of spin J and projection M:

The operator well known fermion number operator

(III-8)

Page 69: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

62

Vpair4JMI0> = - G( ^ ~ ~ ) A00A00AJmI0>‘4

Since A^^|0> = 0, the term 10> may be added with no

effect. Thus,

VpairAJM10> * .

For J£0 the commutator applied to the vacuum state vanishes,

leaving two-particle levels of J*0 unaffected. For J=0

VpairA00|o> " -0!MSol°> (111-10)

since the number operator W applied to the vacuum state gives

zero. Thus A ^ | 0 > is an eigenfunction of Vpalr with eigen­

value -Gft. The spectrum of vpair is degenerate for all

values of J*0, and the J=0 level is depressed for G>0, by

E=-Gft.

The generalization of the above results has been carried

out1*3 with the result that the energy for an N particle sys­

tem of seniority o is given by

E(N,u) = -|(N-u)(2fl-N-u+2) . (III-ll)

Inspection of this equation yields the following conclusions:

(.t) For N<<ft the levels of lowest seniority lie lowest, with

energy increasing with u and level spacings M5. For every

pair which couples to zero, we gain Gft in energy. The ex­

clusion principle, however, prevents the process from continu­

ing indefinitely. (-cc) The level density is predicted to be

very low near the ground state, although the total number of

levels increases with N. (jLIa,) The energy gain for the ground

state (u=0) is, for N<<ft proportional to N, in contrast to

Page 70: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

the energy of a quadrupole interaction, which Is proportional

to N 2.

Casting equation (III-ll) in a slightly different form:

E(N,u) = - | [N(2ft+2-N) -i) (2ft+2-u)] (III-lla)

shows the very similar dependence on the number of particles

and on the seniority more explicitly. Clearly, this expression

for constant N is minimized for u=0, which can only occur for

the J=0 ground state, since all pairs will then be coupled

to ■Jpaij,''0 * Figure 1 shows the parabolic dependence of the

energy E(N,u) on both the number of particles N and the senior­

ity u. The graphs for both N and u are symmetric and peaked,

not about the middle of the shell (ft=/+7/2), but rather about

ft+1. The seniority (upper) curve, however, does not pass

beyond ft or ft-1, depending on whether ft is even or odd, re+

spectively. The number (lower) curve, of course, does not

pass beyond 2ft=2/+J, which is the maximum number of particles

allowed in the shell. Keeping seniority fixed, the energy

(III-lla) decreases with increasing number of particles until

N=ft+1, after which it increases, but does not return to its

original value for N=2ft. Instead, there is a residual pairing

energy given by -Gft, which, coincidently, is the same as the

lowering of the J=0 level in the two-particle spectrum.

63

3. The Hamiltonian of the Individual-Particle Model

The Hamiltonian used in these calculations is a linear

combination of the pairing (III-9) and quadrupole-quadrupole

(III-2) interactions discussed in the previous section. We

Page 71: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 1. Variation of pairing force energy in a (j)n configuration with the seniority and the number of particles N. The seniority curve terminates at ft-1 for /+I/2 odd, and at ft for y+7/2 even. The number curve terminates at 2ft, leaving a residual pairing energy associated with a closed shell of -Gft.

Page 72: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

PAIRING

FORCE

ENERGY

-G £2

o o*

a = - ^ r ( 2 i l + 2 - N ) + - f - U U 1 ) 2 4 4

b = --r-(2G + 2 - N )

Page 73: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

64

h(x) = LilLZlL(i_x)vpalr + (x) vquad. ox<x<i (111-1 2)Fnorm

The normalization factor (/+//2)/E , yields, for G=1 MeV,J norm' J * *a separation energy of 1 MeV between the highest and lowest

seniority states. E is E(N,0) or E(N,1) for even or oddnorm ’

N, respectively.

The single-particle states used are shell model

states. Since the particles are restricted to a single j

shell, the only quantum number needed to describe the individual

particle states is the magnetic quantum number. As discussed

in section II.1, the intrinsic states all have M. .=0 or* -cn t

h n t * 1 / 2 -

The projection techniques discussed in section II.3

have been applied to the above problem for 5/2</<15/2, to

yield the complete exact spectra of the Hamiltonian (111-12).

The energy matrices were calculated parametrically in the

strengths of the two-body angular momentum components of the

matrix elements of the Hamiltonian, so that the N-body

matrices of any other two-body force may, at this point, be

easily obtained from its two-body matrix elements. The com­

puter codes used in these calculations are presented in

Appendix B-I.

define a mixing parameter X by the following:

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65

4. Seniority Composition of Wave Functions

For X=0— for the pairing interaction (III-9)— seniority

is a good quantum number. If the overlap of the eigenvectors

of the Hamiltonian (111-12) for X#0 with those for X=0 is

calculated, the exact seniority composition of the eigenstates

may be obtained for the entire range of the mixing parameter

X. This may be seen as follows.

The time independent Schrodinger equation may be written

for the system for any value of the mixing parameter X:

H(X)^(X) = E^(X)^(X) (111-13)

where H(X) is the Hamiltonian (111-12). The wave functions

of total angular momentum J are further labeled by the sub-

script k, and are continuous functions of X . In particular,

for X-0, the Hamiltonian is a pure pairing interaction, so

that the eigenfunctions may also be labeled by the seniority

u:

H ( 0 ) ^ » U (0) = E^(0)i|^’u (0) . (III-14)

The wave functions of (111-13) may be expanded in terms of

the seniority eigenfunctions of (111-14) at X=0:

^ ( X ) = I ( i n - 1 5)^ p \)

The amplitudes may be easily obtained by taking the over­

lap of (111-15) with the seniority functions:

< ^ ' U (0)|i^(X)> = I fa ^ ( X ) < ^ ,U(0)|^'°'(0)>.& p V)

^ The continuity of the eigenfunctions is guaranteed if the operator H is holomorphic in the parameter X.1*5

Page 75: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Since the seniority functions form an orthonormal basis,

this reduces to

< ^ ' U( 0 ) | ^ ( X ) > = a ^ i ( X ) *

The desired numbers are the intensities of the seniority mix­

tures for the wave functions of (111-12):

Xk ’V (X) = £ (ak ; i ( X ) ) 2 = I C < ^ f V (0 ) l ^ ( X ) > J 2 . (1 1 1 - 1 6 )

In this manner, the exact seniority mixtures have been

obtained for all states throughout the range of the mixing

parameter X.

5. Results of Calculations - Even Number of Particles

a. Distortion of Rotational Bands at High Angular

Momentum Values

The calculated spectra of the Hamiltonian (111-12)

(Figures 2-8) may be analyzed with respect to a variation of

the two parameters / and n. Since the main concern is with

a comparison of these projection calculation results- with the

predictions of a collective model (v. Appendix A-II), consid­

eration is given only to the quadrupole-quadrupole Interaction,

which Is known to give rise to collectivity because of its

relatively long range.

The association of a long range interaction with non-

spherical equilibrium shapes of the nucleus leads to the

expectation that the spectrum of the quadrupole-quadrupole

interaction in (/)n configurations would be highly rotational,

i.e., it would follow the J(J+I) rule for rigid rotators. If

66

Page 76: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

67

we consider comparing the calculated energy levels to a

J(J+7) spectrum, with the moment of inertia parameter obtained

from the excitation energy of the first J=2 state relative

to the ground state, we find that the calculated excited

states are all depressed relative to those of the rigid rota­

tor. Figure 9 shows the ratios = (E^-Eq )/(E2-Eq ) and

R62 = ^E6_E0^‘ E2'‘Eo L where Eq , E2 etc. are the energies

of the first J=0, 2, etc. levels, respectively. Also shown

are the pure rotational limits R ll2=10/3 and Rg2=7* We see

that increasing the particle angular momentum / has a pro­

nounced effect on the deviation of the calculated spectra

from the rotational limits. We can make the observation that

the nuclear configuration becomes more rigidly deformed with

n 4an increase in /. However, even for (/) = (15/2) (which

might occur in the low-energy regions of excitation only of

heavy mass nuclei such as are found in the lead region), the

deviation from the rotational J(J+J) energy dependence is

significant at and above J=8. This type of distortion of

high angular momentum states of rotational bands is a rather

common experimental observation. It has also been interpreted

as a cut-off rather than distortion at high angular momentum.

In order to find the reason for the deviations - from a

pure rotational spectrum noted above, the exact form of the

quadrupole-quadrupole force should be examined. The only

angular momentum dependent factor in the two-body energy

expression (III-4) is the Racah coefficient W(y///;2J). The

closed expression for this coefficient is1*1*

Page 77: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

W(///j;2J) = - 6 flliilLi] {A(A+1) - ik/(/*I)3*L (III-17)M 2 / + 3 ) " 3

whereA = = | </!.J|?-?l/2.J>.

It is easily seen that the coefficient has the form

W = a(/)[J(J+n]2 + 7 (J+7) C 7-4/(/+ 7) ] + b(/) (III-1 8)

where a (/) and b (/) tend to constants with increasing j. Thus

the pure rotational J {J+ 7)energy dependence is not even

indicated in the two-particle spectrum except for j » J . We

can therefore expect the energy spectrum to follow the J(J+/)

rule only for the first few values of J. The dependence for

higher J-values is given by

W 'v, J(J+H - c (/)J2 (J+ 7) 2

which is reminiscent of a nonrigid rotator for which the

equatorial diameters increase while the polar diameter shortens,

thus causing a slight decrease in the energy. This is just

the expression describing the rotational states of an axially

symmetric nucleus including rotation-vibration interaction.

Of course, for j becoming very large, equation (111-18)

effectively predicts the rotational J(J+I) energy dependence

exactly.

The Racah coefficients, for various values of the par­

ticle angular momentum j are presented in Figure 10. Except

for multiplicative factors, which change the scales for dif­

ferent values of j, these are the two-particle spectra. Here

the deviations from pure rotational spectra for higher J-values

is very evident. Indeed, the rotation-like bands may be con-

68

Page 78: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

sidered to be cut off, not at the maximum value of angular

momentum permitted by vector coupling, but rather at some

lower value. For example, the highest rotational state for

(7/2) is the J=4 level, rather than the maximum J=6 .

Figure 11 is a convenient way of presenting results in

the form of a comparison with those of a pure rotator. In

this diagram Rg2 versus R^2 is plotted (cf. Figure 9) for the

2-, 4-, and 6-particle systems for the range of j considered.

We note that Rg2 for (7/2 )** is not shown because it is believed

the rotational band in this problem should be cut off at J=4,

as discussed above. A perfect rotor would lie at the point

(7,10/3).

We have thus shown that the experimentally observed

distortions of rotational band structures, which have previously

found explanation in rotation-vibration competitions, may be

considered to arise solely as a result of the long range

part of the effective interaction. The vibrational modes of

excitation, which are generally associated with pairing, and

consequently with the short range interactions, will be shown

below to arise from the long range part of the effective

interaction.

b. Seniority Analysis and Vibrations Arising from the

Long Range Interaction

Beginning with an empty shell in regions of static pairing,

adding a few particles generally polarizes the core, thus intro­

ducing an effective deformation, and adding still more parti-

69

Page 79: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

cles (up to the middle of the shell) generally increases

this deformation and makes the nucleus more rigid. From

Figures 4, 7 and 5, 8 , it may be seen that for configurations

of particles described by a single angular momentum, inter­

acting through a pure quadrupole force, increasing the number

of particles from four to six (closely approaching the middle

of the shell) increases the distortion of the rotational

spectrum until it appears quite vibrational. We are forced

to conclude that the long range part of the nuclear force

causes nuclei approaching the middle of a shell to have

vibrational modes of excitation in competition with rotational

modes as they undergo transition from prolate to oblate defor­

mations. An explanation of this phenomenon follows from a

seniority analysis of the eigenfunctions of these configura­

tions. 1

The low-lying levels are not good seniority states (v.

Tables I-VII), but seniority does give a fair classification

of the low-energy region of excitation. The states do have

a major component of seniority u=J. The intensities of these

components may be as low as 0 .6 , so that producing, say, the

first J=4 level by a quadrupole excitation of the first J=2

level considered as a pure seniority 2 state is not at all

valid. It is seen that the seniority of this J=4 level is

usually very pure (>95%), while the seniority mixtures of

the J=0 and 2 levels increase with single particle angular

momentum /. For />ll/2, although the low-lying states de­

velop continuously from pure pairing u=2 states, they are

Page 80: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The number of pure seniority states increases suddenly

for n=(2/+7)/2, the middle of the shell (v. Tables I and VI).

This is not a characteristic of the quadrupole-quadrupole

force alone, but rather, as shown below, of any two-pa.’t i d e

scalar operator which may be given as a sum of scalar products

of tensor operators:

no longer u=2 states at X=l, I.e., for a pure quadrupole-quadrupole interaction.

The particular Interaction discussed here, of course, has only

k=2. A simple expression may be obtained for matrix elements

It may be observed that these vanish for n=(2/+7)/2, for which

u<(2/+7)/2; they also vanish for n=u={2/+J)/2. As a conse­

quence, many matrix elements which are non-diagonal in senior­

ity are identically zero, resulting in pure seniority states

in the middle of the shell. This may be considered to re­

present an increase in the amplitude of the J=0 part of the

long range quadrupole force, and an increasing tendency toward

sphericity in the middle of the shell (cf. section III.2c).

This trend toward sphericity is accompanied by a decrease in

V 1 2 = E fK ( D - r K (2).

of (/)W in the seniority scheme in terms of the (/)u matrix

elements;4 6

i<h Tih

2j +1 - 2n i n - v + Z ) (2y+3-n-u) < -u

2/+J-2u ^ 2(2y+3-2u)<y u ,u,a,J|Ei<hV i h |yu , u - 2 ,a'

(111-18)

J

Page 81: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

the frequency of shape oscillations, and consequently a

lowering of vibrational modes of excitation. This may be

understood from a consideration of equation (A-II-la),

which shows that the effective equilibrium radius R q of the

nuclear surface is increased with the approach, in the middle

of the shell, toward sphericity. Equation (A-II-4) then

shows that an increase in the equilibrium radius is accompa­

nied by a lowering in the frequency of shape oscillations,

and therefore a lowering of the energy associated with vibra­

tions of the nuclear surface about some equilibrium distortion.

Experimentally, no such trend toward sphericity is

observed. For example, nuclei in the first half of the 26-1dp Q

shell have prolate equilibrium shapes. At Si there is an

abrupt change to oblate shapes, which continue throughout

the latter half of the shell. The fact that the associated

vibrational spectra are not observed In mid-shell regions

reinforces the hypothesis that nuclei do not contain low-

energy (/)n configurations (cf. section III.l).

72

Page 82: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 2. Pairing + Quadrupole spectrum of (7/2)4 configuration for complete range of mixing parameter X. Pure pairing states are labeled by.seniority u. All states are labeled by spin J.

Page 83: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

MIXING

PARAMETER

ENERGY (MeV)

Page 84: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 3. Pairing + Quadrupole spectrum of (9/2) configuration for complete range of mixing parameter X. Pure pairing states are labeled by seniority u. All states are labeled by spin J.

ij

Page 85: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

ENER

GY

(MeV

)

XMIXING PARAMETER

Page 86: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 4. Pairing + Quadrupole spectrum of (11/2)^ configuration for complete range of mixing parameter X. Pure pairing states are labeled by seniority u. All states are labeled by spin J.

Page 87: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

XMIXING PARAMETER

Page 88: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 5. Pairing + Quadrupole spectrum of (13/2)1* configuration for complete range of mixing parameter X. Pure pairing states are labeled by seniority u. All states are labeled by spin J.

Page 89: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

XMIXING PARAMETER

Page 90: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 6. Pairing + Quadrupole spectrum of (15/2)** configuration for complete range of mixing parameter X. Pure pairing states are labeled by seniority u. All states are labeled by spin J.

Page 91: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

XMIXING PARAMETER

Page 92: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 7. Pairing + Quadrupole spectrum of (ll/2)b configuration for complete range of mixing parameter X. Pure pairing states are labeled by seniority u. All states are labeled by spin J.

Page 93: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

XMIXING PARAMETER

Page 94: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 8. Pairing + Quadrupole spectrum of (13/2)^ configuration for complete range of mixing parameter X. Pure pairing states are labeled by seniority u. All states are labeled by spin J.

Page 95: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

° V# G V r -

Page 96: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 9. Comparison of Projection Calculations to Rigid

Rotator Data. The curves are the ratios R^^ = E 4“E2 ^ (E 2—E0 and Rb2=(Eg-E2 )/(E2-E0 ), where EQ , E2 , etc., are the excita­

tion energies of the first J=0, 2, etc. levels.

Page 97: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

PARTICLE

NUMBER

8

<0it 4 c

0 L

8

•• 4C

0 L-

8

CJii 4c

I

R 62

R 4 2

R 6 2

R 4 2

R 6 2

1 1 J5 / 2 7/2 9/2 11/2 13/2 15/2

]S I N G L E - P A R T I C L E A N G U L A R M O M E N T U M

Page 98: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 10. Two-particle Quadrupole-Quadrupole Spectra for 5/2</<J5/2. The energy spectrum is simply proportional to the Racah coefficient W(////;2J) (v. equation (III-4)).

Page 99: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

0.08 -

0 . 0 6

0 . 0 4

0 . 0 2

0 . 0 0

4,6

8

8

10

108

612

•1012

8

6,14

_ - 0 . 0 2

OJ • ^

- 0 . 0 4

- 0 . 0 6

2

0

- 0 . 0 8

-0. I 0

■0. I 2

-0. 14

-0. 16

J i i i I I I I I I 1-----15 / 2 7/2 9/2 11/2 13/2 15/2

J S I N G L E - P A R T I C L E A N G U L A R M O M E N T U M

Page 100: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 11. Comparison of Projection Calculations to Rigid Rotator Data. EQ , E2 , etc., are the excitation energies of the first J=0, 2, etc. levels. 2P, 4P, and 6P represent 2-, 4-, and 6-particle configurations'.

Page 101: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

0UJ1CM

UI\0

UJ1<0

UJ

E 4 - E q / E 2 - E o

Page 102: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Quadrupole-Quadrup ole Int e ra c t ion

4Table I - Seniority Analysis of (7/2) Configuration

J i)-0 u=2 u=4

0 1 - -

2 - 1 -

4 - - 1

4 - 1

6 - 1 -

2 - - 1

8 - - 1

Page 103: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

4Table II - Seniority Analysis of (9/2) ConfigurationQuadrupole-Quadrupole Interaction

u S0

0

2

46

6

48

2

10

8

46

0

1 2

,9390

, 0 6 1 0

u® 2

.9313

. 9 1 6 6

.8462

. 9 2 0 0

.0687

. 0 8 0 0

.1538

.0834

. 0 6 1 0

.06871

1

.0834

.1538

.0800

.93131

. 9 2 0 0

.8462

. 9 1 6 6

.93901

Page 104: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Table III - Seniority Analysis of (11/2)** ConfigurationQuadrupole-Quadrupole Interaction

J u -0 ua40 .8368 - .1632

2 - .8437 .1563

4 - .0149 .9851

6 - .1696 .8304

8 - .2140 .7860

8 - .5742 .4258

2 - .1291 .8709

4 - .8372 .1628

10 - .9101 .0899

6 - .6832 .3168

12 - - 1

10 - .0433 .9567

4 - .1080 .8920

8 - .0025 .9975

6 - .0083 .9917

0 - .1632 .8368

14 — - 1

6 - .1390 .8610

16 ' - - 1

8 — .2092 .7908

4 - .0399 .9601

2 - .0273 .9727

10 - .0466 .9534

12 — — 1

v

Page 105: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Table IV - Seniority Analysis of (13/2)^ ConfigurationQuadrupole-Quadrupole Interaction

J u®0 u = 2 v=4

0 .6698 .3302

2 - .7486 .2514

4 - .0445 .9555

6 - .0850 .9150

10 - .1874 .8126

8 - .2517 .7483

2 - .1452 .8548

10 - .4400 .5600

4 - .7489 .2511

12 - .8478 .1522

8 - .4461 .5539

6 - .7246 .2754

12 - .0008 .9992

14 - - 1

4 — .0380 .9620

0 — .3302 .6698

6 - .1431 .8569

16 — - 1

18 ■ - - 1

14 - - 1

8 - .2399 .7601

20 - - 1

16 — — 1

Page 106: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Table V

J u=0 u*2 u*4

4- Seniority Analysis of (15/2) ConfigurationQuadrupole-Quadrupole Interaction

0 .5683 - .43172 - .6902 .3098

4 - .0795 .92056 - .0392 .9608

12 - .1720 .8280

8 - .2077 .7923

10 - .2511 .74892 - .1036 .89644 - .5986 .4014

14 - .6781 .3219

10 - .3097 .69030 .4284 - .5716

16 1

12 - .0251 .974924 - 1

22 1

1 8 1

14 .0066 .9934

20 1

Page 107: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Table VI - Seniority Analysis of (11/2)^ ConfigurationQuadrupole-Quadrupole Interaction

0

2l«

6

2

6

48

1 0

6

8

0

12

410

6

8

41410

6

12

1 2

16

46

140

8

10

418

u®0

.8755

u g 2

.9663

. 0 0 3 6

.4512

.6639

.6853

.6748

. 2 8 3 6

.3672

.0411

.1245

.0416

.0931

. 1 8 1 6

u - 4

,1245

1

1

1

1

1

1

1

1

1

1

1

1

1

,8755

u g 6

.0337

.9964

.5488

.3361

.3147

.3252

1

.7164

. 6 3 2 8

1

.9589

.9584

.9069

.8184

1

Page 108: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Table VII - Seniority Analysis of (13/2)b ConfigurationQuadrupole-Quadrupole Interaction

J u 30 u =2 o=4 u -60 . 6 8 3 6 - . 2 6 2 2 .0542

2 - .7236 .1741 . 1 0 2 2l\ - .0086 . 8 0 8 0 .1834

6 - .0347 .0459 .9194

8 - • .0227 .1596 .8177

2 - . 1 6 6 1 .6103 . 0 2 3 6

8 - .0249 . 7 8 1 0 .1941

4 - .3338 .1695 .4967

10 - . 0 1 7 8 .7420 .2402

10 - .4686 .0367 .4947

12 - .4880 .0644 .4476

6 - .4386 .1291 .4323

0 . 1 0 3 2 - .0123 .8845

4 - .0369 .5440 .4190

14 - - .8404 .1596

8 - .0354 .1667 .7979

1 2 - .0487 .6511 . 3 0 0 2

1 0 - .0517 .4039 .5444

6 - .0004 . 6 3 6 6 .3630

4 — . 2 7 1 6 . 1 1 2 0 .6164

2 - .0223 .1736 .8041

16 — - .1299 .8701

1 8 - - .1349 .8651

20 - - .7929 .2071

0 .1679 - .4617 .3704

22 - - - 1

20 — - .2071 .7929

24 _ — 1

Page 109: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

6. Results of Calculations- Odd Number of Particles

The complete quadrupole-quadrupole spectra for /*9/2

and /*M/2, and the low-lying spectra for /*/3/2 and /* 7 5/2

are shown for w=3 and 5 particles in Figures 12 and 13.

Of special Interest is the approach, with increasing particle

angular momentum /, to an evenly spaced band of J*K, K+l,

K+2,.... In the shell model these bands would begin at K=/

because of pairing effects of the short range part of the

nuclear interaction. However, here the absence of this

short range part of the force is conspicuous by the bandsC

beginning with K=/-2 for (/) configurations, and with K=/-/O

for (/) configurations. This is true in the cases shown

except for /=9/2, which reflects the fact that n=5 marks

the middle of the 9/2 shell. It appears that the farther

from the middle of the shell the cleaner this band will be.

A spectrum beginning with K=/ can certainly be obtained by

choosing values other than unity for the mixing parameter X,

i.e., by including short range interactions. It is to be

noted that these results are in agreement with a collective

model (cf. Appendix A-II) for oblate deformations.113

At first glance, it might appear that the surface-

coupled model cannot be applied to the (j)n calculations

since the system contains too few particles, and thus the

core is conspicuously absent. There are two ways out of

this predicament. First, the "core" may be replaced by the

average field it produces which, in Its turn, produces the

good quantum numbers j of the individual particles. Particle

73

Page 110: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 12. Complete quadrupole spectra of (9/2)3, (11/2)

(13/2)3, and (15/2)3 configurations.

Page 111: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

ENERGY

(MeV)

27/2

1.0

0.5

-0.5

-1.0

1.5

15/2 21/215/2

■ 2 7 / 2

•15/2

•21/2

21/29 / 2

•17/2

3 / 2

5 / 2

13/2,11/2

• 9 / 2 • 2 3/2

• 2 7/2

•3/2

•17/2• 11/2• 19/2

5 / 2■7/2

•9/2,23/2- 2 9 / 2" 1 7 / 2

.,3/2" 2 5 / 2

■5/2' 3 3 / 2

11/2

• 13/2

■ 21/2

19/2■ 9 / 2• 7 / 2

15/2

13/2

9 / 2

■17/2

15/2

7 / 211/2

9 / 21 3 / 2

11/2

I___L

•21/2

• 3 3 / 2

•15/2

■ 2 3 / 2 , 2 9 / 2

9 / 2.17/2-31/2^ 3 5 / 2 , 3 / 2

11/2-5/2,19/2 :2 7 / 2 , 2 5 / 2 7 / 2

• 3 9 / 2 rl 3 / 2 15/2

2 3 / 2

• 11/2 r 9 / 2

21 /2

19/2

17/2

15/2

1 3 / 2

9 / 2 11/2 J 13/2 15/2

S I N G L E - P A R T I C L E A N G U L A R M O M E N T U M

Page 112: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 13. Quadrupole spectra of (9/2)^, (11/2)^, (13/2)^ (15/2)^ configurations.

Page 113: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

ENERGY

(MeV)

2 .0

1.5

.0

0.5

-0.5

- 1.0

-1.5

-2 . 0

-2.5 L

■ 25/2

• 9/2 ,13/2 19/2

■ 3/2 "7/2

17/2

•21/2,9/215/2

11/2"15/2

1/2

17/2

11/2

13/25/2

9/25/27/2

I__ L9/2

23/2y^f-17/2,15/2"25/2,9/2,7/2

'11/2 N5/2.I7/2

21/2'23/2,13/2

✓17/2-11/2-3/2"l9/2

13/2

11/2

■9/2■7/2

-15/2

,25/2-11/2

5/213/221/25/2,9/2,19/27/2

■ 17/2

■15/2

■ 13/2

- 11/2

-9/2

21/2,29/2

27/2

25/2

.11/2 ✓9/2 "23/2 7/2 -21/2

19/2

17/2

15/2

13/2

11/2J___I

11/2 13/2 15/2J

S I N G L E - P A R T I C L E A N G U L A R M O M E N T U M

Page 114: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

74

excitations of this core are negligible compared to valence

nucleon excitations since the low energy excitations of

nucleons below the Fermi level are primarily collective,

neighboring particle states being fully occupied (cf. sec­

tion 1.2b).

A different viewpoint may be assumed; the "core" may

be considered-made up, self-consistently, of the "extra-

core" particles (cf. Chapter IV). To appreciate this model,

we consider a system of two nucleons interacting via a

central force. The Hamiltonian for this system is given by

= - ^ ( V2 + V| ) + V(A), (111-19)H2M

where M is the mass of the nucleon. Separating the Hamil­

tonian into relative and center-of-mass coordinates:

Hrel = - — V 2 + V U )M

H ' = - — V2cm ijjvj R

The time-independent Schrodinger equation for the relative

motion of the nucleons Is

V 2i|> + -2 [E-V(*)]iJ/ = 0. (III-20)

As is well known, this equation is separable in spherical

coordinates, and has the solution

Page 115: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

75\

£The spherical harmonic may be regarded as a rotational

function and the radial function as intrinsic. then

has the same form as the eigenfunctions (A-II-15). We consider,

for example, two nucleons Interacting via the harmonic oscil­

lator potential. The energy levels of this system may be

arranged in bands, each characterized by an Intrinsic, or

radial quantum number (n = number of oscillator quanta). The

rotational motion undeniably exists, although the spectrum

does not follow the 1(1+7) energy rule of a rotor. This is

because the rotational energy Is of the same order as the

intrinsic excitations and the centrifugal force distorts the

intrinsic structure. The two degrees of freedom are strongly

coupled, as evidenced by the dependence of the radial function

on the quantum number Z.

The example above demonstrates how a collective inter­

pretation may be given to a system comprised of only two

particles, but does hot clearly indicate the applicability

of the surface-coupled model discussed in Appendix A-II.

To determine the extent of its validity for the calculations

reported in this chapter, consider a system of particles

interacting via the quadrupole-quadrupole force (III- 2)

The average field experience by particle i, expressed as a

function of the coordinates of the intrinsic frame is

with(1 1 1 - 2 2 )

Page 116: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

where an averaging over the coordinates of the particle

has been performed. This clearly demonstrates that each

individual particle undergoing quadrupole interactions with

all of its neighbors behaves as if, on the average, it were

interacting with a quadrupole deformed surface.

Equation (A-II-16) indicates that for oblate deformations

the ground state of a system of odd n would be I=K=ft=/. Since

this is not borne out by the calculations performed, (as seen

above, the ground state is given by K=/-J for n=3, and by

K=j-2 for n=5) it can only be inferred that the nucleon

averaging discussed above is not applicable since there are

too few particles present. Consideration must therefore be

given to a surface-coupled model involving several external

particles.

The competition between particle forces and surface

interactions will determine the nuclear coupling scheme most

appropriate. If the forces are weak compared to the coupling

of the individual particles to the nuclear surface, the

particle angular momenta remain good quantum numbers and the

coupling scheme may be depicted as in Figure 14a. The effect

of the particle forces is then to contribute a small energy

shift, which depends on the ft quantum numbers. Such effects

may be significant if there are near-lying states of different

ft, such as in odd-odd nuclei.

With increasing strength the particle forces introduce

non-diagonal terms in the ft^ For very strong forces, the

particle structure is coupled to a resultant angular momentum

76

Page 117: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 14. Coupling schemes for many-particle configurations.

In many-particle configurations, the coupling scheme results from a competition between surface coupling and particle forces. Two extreme cases are shown: (a) Surface coupling dominates over particle forces. The particles move indepen­

dently of each other in the deformed nucleus, each having a constant component ft of angular momentum along the symmetry axis. The total ft equals ^ ft^ and the nuclear ground state has I=K=ft. The figure illustrates the coupling scheme for a (j) configuration. The three lowest particle states have

and leading to I=ft=y~7. (b) Particle forces

dominate over surface coupling. The particles are coupled to a resultant 5, which is then coupled to the surface as a single particle. The figure refers to a (y)^ configuration, where the particle forces, in general, favor the state J=y. The resultant ground state has I=ft=J=y.13

Page 118: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

z1

(b)

Page 119: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

J . T h is i s th e n coup led to th e s u r fa c e in th e same manner

as a s in g le p a r t i c l e . The ground s ta te s p in I= J is d e te rm ine d

by th e p a r t ic le fo rc e s (v . F ig u re 1 4 b ).

I t i s im m e d ia te ly seen th a t weak c o u p lin g p redom ina tes

in th e c a lc u la t io n s re p o r te d s in c e th e ground s ta te s p in s f o r

odd n a re g iv e n by ( n - 1 ) / 2 .

7 . Summary

P r o je c t io n c a lc u la t io n s have been c a r r ie d ou t in th e

com plete ( j ) n space 5 /2 $ /$ 1 5 /2 , th e nuc leons In te r a c t in g th ro u g h

a s im p le phenom eno log ica l fo rc e w h ich accoun ts f o r th e main

c h a r a c te r is t ic s o f r e a l n u c le i . An e xa c t s e n io r i t y a n a ly s is

was p e rfo rm ed on th e above e ig e n s ta te s . The fo l lo w in g r e s u l ts

have been o b ta in e d :

( JL) D e v ia t io n s from an expected t ru e r o ta t io n a l spectrum

have been a t t r ib u te d to th e tw o - p a r t ic le quadrupo le in te r a c t io n

i t s e l f , w h ic h , as has been shown, i s capab le o f e x h ib i t in g

r o t a t io n a l s p e c tra o n ly f o r low a n g u la r momentum v a lu e s . F o r

h ig h e r va lu e s th e two p a r t i c le spectrum is th a t o f an a x ia l l y

sym m etric n u c le u s u nd e rg o in g r o ta t io n - v ib r a t io n in t e r a c t io n .

( U ) The pure quad ru p o le in t e r a c t io n was shown to g iv e

r is e to a v a r ia t io n in th e shape o f th e "n u c le u s " . The wave

fu n c t io n s , w ith an in c re a s in g number o f p a r t ic le s , a t f i r s t

approach those o f a t ru e r o t o r , b u t th e n , w ith the approach

to th e m id -s h e l l r e g io n , become more s p h e r ic a l in unde rgo in g

t r a n s i t io n from p r o la te to o b la te d e fo rm a tio n s .

{JU.JL) S p e c tra in th e m id - s h e l l re g io n s lo o k rem a rkab ly

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78

l i k e pure v ib r a t io n a l e x c i t a t io n s p e c tra . T h is i s a t t r i b ­

u ta b le to a marked in c re a s e in th e number o f pure s e n io r i t y

s ta te s in t h is re g io n . I t has been shown th a t t h is is a

g e n e ra l fe a tu re o f any tw o - p a r t ic le in te r a c t io n w h ich may

be g iv e n as a sum o f s c a la r p ro d u c ts o f te n s o r o p e ra to rs .

{ i . v ) The lo w - ly in g e x c i ta t io n s p e c tra was found to

have a m a jo r component o f s e n io r i t y o=J.

(v ) Odd mass c o n f ig u ra t io n s were found to d is p la y

r o t a t io n a l band s t ru c tu re s b e g in n in g w ith K = / - ( n - J ) /2 .

r a th e r th a n th e expected K = /. T h is was shown to be e x p l ic a ­

b le in te rm s o f th e weak c o u p lin g m ode l, and to agree w ith

p r e d ic t io n s o f th e c o l le c t iv e model in w h ich th e n p a r t ic le s

a re c o n s id e re d coup led to a deform ed n u c le a r f i e l d .

As p re v io u s ly m e n tion e d , e x p e rim e n ta l d a ta does n o t

u pho ld th e assum ption o f pu re ( j ) n c o n f ig u ra t io n s w i t h in th e

n u c le u s . In an a tte m p t to f u r t h e r s tu d y th e r e la t io n between

m acroscop ic and m ic ro s c o p ic models o f n u c le a r s t r u c tu r e , we

tu r n now to a d is c u s s io n o f th e more r e a l i s t i c H a rtre e -F o c k

c a lc u la t io n s . H ere , in d iv id u a l p a r t ic le s a re assumed to move

in an average (m a cro sco p ic ) n u c le a r p o t e n t ia l , gene ra te d s e l f -

c o n s is te n t ly by a l l o f th e a c t iv e p a r t ic le s . E x c i ta t io n s o f

th e H a rtre e -F o c k s ta te a re c o n s id e re d in an a tte m p t to f in d

c o r re c t io n s to th e q u a s i- r o ta t io n a l H a rtre e -F o c k band.

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CHAPTER IV

HARTREE-FOCK STUDIES

R o ta t io n a l s t r u c tu r e has lo n g been th o u g h t to e x is t

in th e n u c le i o f th e 24- I d s h e l l (16<A<40). The main

c h a r a c te r is t ic s o f these n u c le i w h ich le a d to an in te r p r e ­

t a t io n as r o t a t io n a l s t ru c tu re s a re th e s im i la r i t y o f th e

lo w -e n e rg y e x c i t a t io n s p e c tra to th a t o f a r o t o r , and the

e x h ib i t io n o f s tro n g q uad rupo le t r a n s i t io n and s t a t i c m u l t i ­

p o le moments. The appearance o f r o t a t io n - l i k e s t r u c tu r e

in d ic a te s a degree o f asymmetry in th e average p o te n t ia l

f e l t be each n u c le o n ; a s p h e r ic a l ly sym m etric system cannot

undergo quantum m echan ica l r o ta t io n s . T h e re fo re , in c re a t in g

an in d iv id u a l - p a r t i c le model to in t e r p r e t th e e x p e rim e n ta l

d a ta f o r these n u c le i , s p e c i f ic accoun t must be ta ke n o f the

d e p a rtu re o f th e average n u c le a r p o te n t ia l f i e l d from sp h e r­

i c i t y . The use o f th e s p h e r ic a l j - J c o u p lin g scheme does

n o t seem s u ita b le f o r such cases ; a deform ed b a s is w ould be

m ore .a p p ro p r ia te . A s p h e r ic a l b a s is may, how ever, be u t i l i z e d

in c o n f ig u r a t io n in te r a c t io n c a lc u la t io n s , in w h ich an a tte m p t

is made to in c lu d e asymmetry e f fe c ts by m ix in g d i f f e r e n t

s p h e r ic a l s o lu t io n s w h ich l i e c lo s e in e n e rg y . U n fo r tu n a te ly ,

these c a lc u la t io n s a re p r o h ib i t i v e ly lo n g and c o m p lic a te d f o r

a l l b u t th e s im p le s t o f n u c le i .

An i n t r i n s i c deform ed n u c le a r s ta te re p re s e n ts a system

o f n o n - in te r a c t in g p a r t ic le s In a deform ed p a r t i c le b a s is

g e n e ra te d by some " s e l f - c o n s is te n t " t re a tm e n t o f e i t h e r a l l

1. Introduction

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o f th e nuc leons co m p ris in g th e n u c le u s , o r m ere ly those

n uc leons co n s id e re d to be " a c t iv e " . I t i s n o t an a c tu a l

s ta te o f th e n u c le u s , b u t r a th e r a c ts as a b a s is from w h ich

th e p h y s ic a l s ta te s may be e x t ra c te d . R e d lic h 1' 6 has demon­

s t r a te d th a t th e r e s u l ts o f s h e l l model c o n f ig u ra t io n i n t e r ­

a c t io n c a lc u la t io n s may be app rox im a ted by p r o je c t in g o u t

th e e ig e n s ta te s o f a n g u la r momentum from t h is i n t r i n s i c

deform ed s ta te o f th e n u c le u s . The p ro je c te d q u a s i- r o ta t io n a l

band co rresponds to th e a c tu a l s ta te s o f th e n u c le us i f most

o f th e n u c le o n -n u c le o n in te r a c t io n is absorbed in p ro d u c in g

th e deform ed s ta te , i . e . , c o n ta in e d in th e s e l f - c o n s is te n t

one-body p o t e n t ia l , so th a t th e r e s id u a l in te r a c t io n s a re

s m a ll.

The deform ed p a r t i c le b a s is may be o b ta in e d by a s e l f -

c o n s is te n t H a rtre e -F o c k (h e re a f te r HF) c a lc u la t io n . H a r tre e -

Fock th e o ry p ro v id e s a c o n n e c tio n between th e m acroscop ic

d e s c r ip t io n o f n u c le a r d e fo rm a tio n s g iv e n by an average

n u c le a r p o t e n t ia l , and th e m ic ro s c o p ic d e s c r ip t io n in term s

o f in d iv id u a l p a r t ic le s . I t i s assumed th a t each n uc leo n

moves in d e p e n d e n tly in a deform ed p o te n t ia l w e l l a r is in g

s e l f - c o n s is t e n t ly from i t s one- and tw o-body in te r a c t io n s

w ith a l l n u c le o n s , averaged ove r th e wave fu n c t io n s o f th e

o th e r n u c le o n s .

The e f f e c t o f s e lf - c o n s is te n c y on r a d ia l m o tion s may

be im p o r ta n t f o r an e x p la n a t io n o f th e s a tu ra t io n p ro p e r t ie s

o f th e n u c le u s , i . e . , b in d in g e n e rg ie s and e q u i l ib r iu m r a d i i ,

b u t n o t f o r th e lo w -e n e rg y e x c i t a t io n s p e c tra . T h e re fo re ,

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two typ e s o f HF c a lc u la t io n s a re g e n e ra lly p e rfo rm e d —

r a d ia l c a lc u la t io n s f o r c lo s e d - and n e a r - c lo s e d -s h e ll

n u c le i , and deform ed c a lc u la t io n s f o r n o n -s p h e r ic a l n u c le i .

R a d ia l wave fu n c t io n s a re v a r ie d when i t i s th o u g h t th a t

m a jo r s h e l l m ix in g sh o u ld be ta ke n In to a cco u n t. In th e

. l a t t e r , th e r a d ia l p a r t o f th e p a r t ic le wave fu n c t io n i s

f ix e d , u s u a l ly as th e harm onic o s c i l l a t o r wave fu n c t io n

(as a m a tte r o f c a lc u la t io n a l c o n v e n ie n c e ); s e lf - c o n s is te n c y

is Imposed o n ly on th e o r b i t a l and s p in p a r ts o f th e wave

fu n c t io n . I t i s th u s assumed th a t th e ,la c t I v e ,, p a r t ic le s

may be c o n fin e d to a h ig h ly t ru n c a te d H i lb e r t space. I t is

t h is typ e o f c a lc u la t io n to w h ich re fe re n c e i s made in t h is

p re s e n ta t io n .

S ince an e xa c t s o lu t io n o f th e n u c le a r many-body

p rob lem is im p o s s ib le ( c f . C hap te r I ) , th e ch o ice o f an

in d iv id u a l p a r t i c le re p re s e n ta t io n cannot be made on th e

b a s is o f m a th e m a tica l conven ience a lo n e ; th e v a l i d i t y o f

a p p ro x im a tiv e te ch n iq u e s depends upon th e p a r t i c le re p re ­

s e n ta t io n b e in g used. Warke and Gunye1*7 have a rgued ,

a lth o u g h n o t r ig o r o u s ly , th a t th e deform ed s ta te o u t o f

w h ich th e lo w - ly in g q u a s i- r o ta t io n a l band i s p ro je c te d ,

sh o u ld be th e HF s ta te r a th e r th a n any o th e r . There i s a

b a s ic d if fe re n c e between the HF re p re s e n ta t io n and o th e r

bases o b ta in e d m e re ly by th e a p p l ic a t io n o f a u n i ta r y t r a n s ­

fo rm a tio n to th e s p h e r ic a l s h e l l model r e p re s e n ta t io n : th e

HF p a r t i c le wave fu n c t io n s c o n ta in in fo rm a t io n about the

one- and tw o-body in te r a c t io n s in th e system . C a lc u la t io n s

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to t e s t th e p ro je c te d wave fu n c t io n s in th e 2 6 - 1 d s h e l l have

re s u lte d * *8 in good agreem ent w ith s h e l l model r e s u l t s * 9 .

E a r ly successes o f th e p r o je c t io n m ethod20>50-55 in

o b ta in in g deform ed p a r t i c le wave fu n c t io n s w h ich e x p la in e d

p ro p e r t ie s o f n u c le i in th e 2 6 - 1 d s h e l l im p lie d th e e x is te n c e

o f an u n d e r ly in g independen t p a r t i c le b e h a v io r in th e t ru e

wave fu n c t io n s o f these n u c le i . The wave fu n c t io n i s expec­

te d to f a c to r in t o in d iv id u a l p a r t ic le and c o l le c t iv e term s

when p a r t i c le e x c i t a t io n e n e rg ie s a re la r g e r th a n th e energy

a s s o c ia te d w ith c o l le c t iv e e x c i ta t io n s . These c o n d it io n s

a re met by th e even-even N=Z n u c le i o f th e 2 6 - 1 d s h e l l , where

p a r t i c l e e x c i ta t io n s a re in h ib i t e d by a HF energy gap o f

5-8 MeV (v . s e c t io n I V . 4 ) , w h ile th e f i r s t 2+ le v e l o f th e

ground s ta te q u a s i- r o ta t io n a l s e r ie s occu rs a t a p p ro x im a te ly

1 -2 MeV. The 2 6 - I d s h e l l i s a p a r t i c u la r ly c o n ve n ie n t re g io n

o f th e n u c le a r mass ta b le in w h ich to examine th e in t e r r e la ­

t io n s h ip s between models o f n u c le a r s t r u c tu r e . T h is is th e

f i r s t s h e l l in w h ich m ix in g o f d i f f e r e n t £ -s ta te s o c c u rs .

I t has th e fe a tu re o f h a v in g enough degrees o f freedom to make

th e p rob lem n o n t r i v i a l , and n o t so many degrees o f freedom

th a t th e s o lu t io n becomes to o d i f f i c u l t ; th e re a re few enough

p a r t ic le s so th a t in te rm e d ia te c o u p lin g c a lc u la t io n s can be

p e rfo rm e d , and y e t enough p a r t ic le s so th a t c o l le c t iv e models

can be te s te d . I f m acroscop ic and m ic ro s c o p ic th e o r ie s o f

n u c le a r s t r u c tu r e a re to be u n i f ie d , as is th e aim o f t h is

w o rk , no o th e r re g io n appears more f e r t i l e th a n th e 2 6 - 1 d

s h e l l .

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83

The p ro p e r t ie s o f n u c le i in th e f i r s t h a l f o f th e 2 6 - Id.

s h e l l a re s t ro n g ly s u g g e s tiv e o f lo w -e n e rg y e q u i l ib r iu m shapes

w h ich a re de form ed. E x c i ta t io n s p e c tra in t h is mass re g io n ,

o b ta in e d by p r o je c t in g q u a s i- r o ta t io n a l bands from HF s ta te s ,

e x h ib i t spac ings w h ich a re s y s te m a t ic a l ly s m a lle " th a n those

o f e x p e r im e n ta lly observed e x c ite d s ta te s by a fa c to r o f20a p p ro x im a te ly .1 /2 . A n o ta b le e x c e p tio n is Ne , th e p ro je c te d

spectrum o f w h ich agrees f a i r l y w e l l w ith e x p e rim e n ta l o b se r­

v a t io n s ( v . s e c t io n I V . 4 ) . T h is r e f le c t s a more com plete con-20s id e r a t io n , in th e HF c a lc u la t io n f o r Ne , o f th e degrees o f

freedom o f th e a c t iv e p a r t i c le s , th a n in th e c a lc u la t io n s f o r

any o th e r n u c le u s in t h is re g io n .

The use o f n o n - lo c a l one-body p o te n t ia ls ( in th e fo rm o f

a s p a t ia l exchange te rm ) w i l l be shown (v . s e c t io n I V . 4) to

r e s u l t in an energy gap in th e deform ed p a r t ic le spec trum .

HF th e o ry is expected to re p re s e n t a good a p p ro x im a tio n to

th e t ru e s i t u a t io n i f t h is gap is la r g e . I f , on th e o th e r

hand, th e energy gap i s s m a ll, p a r t ic le s sh o u ld be a b le to

s c a t te r across i t , g iv in g r is e to p a r 't ic le - h o le s ta te s w h ich

m ix w ith th e HF s ta te . C a lc u la t io n s in d ic a te th a t t y p ic a l

energy gaps f o r 2 6 - I d s h e l l n u c le i a re o f th e o rd e r 5-8 MeV,

as compared to those o f th e I p s h e l l , w h ich a re a p p ro x im a te ly

18 MeV. I t i s th e re fo re expected th a t p a r t ic le - h o le s ta te s

m ig h t re p re s e n t v a l id a d m ix tu re s to th e lo w -e n e rg y e x c i ta t io n

s p e c tra o f n u c le i in th e re g io n - Ca**^. I t i s th e purpose

o f th e c a lc u la t io n s re p o r te d h e re in to f in d these a d m ix tu re s .

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By i t s v e ry n a tu re , how ever, th e HF s ta te i s s ta b le

a g a in s t 1 - p a r t i c le / l - h o le e x c i t a t io n s . T h is r e f le c t s th e

f a c t th a t th e se e x c ita t io n s have a lre a d y been in c lu d e d in

th e 1-body s e l f - c o n s is te n t p o t e n t ia l . T h is f a c t has been

m is ta k e n ly used by P a l and Stamp56 to ig n o re these e x c i ta ­

t io n s and to c o n c e n tra te on 2 - p a r t ic le /2 - h o le a d m ix tu re s

th ro u g h a r e s id u a l p a ir in g in t e r a c t io n . The a d m ix tu re s w h ich

a re o f im p o rta n c e , how ever, a re n o t those to th e HF s ta te

i t s e l f , b u t r a th e r those to th e in d iv id u a l s ta te s o f th e

q u a s i- r o ta t io n a l band p ro je c te d o u t o f th e HF s ta te . T e w a r i57

has re c o g n iz e d t h is f a c t in a p p ly in g a Tamm-Dancoff a p p ro x i­

m a tio n to o b ta in m ix tu re s to th e HF band and h ig h e r e x c i t a -20t io n s p e c tra in Ne , w ith q u ite rem arkab le r e s u l ts ( v . s e c t io n

V .6 b ) . T h is , how ever, i s an a p p ro x im a tiv e te ch n iq u e in w h ich

a s in g le " p a r t ic le - h o le " s ta te is o b ta in e d as a co m b in a tio n

o f 1 - p a r t i c le / l - h o le e x c ita t io n s o f th e HF s ta te , t h is com­

b in a t io n d e te rm in e d by th e re q u ire m e n t th a t th e f lu c tu a t io n s

o f th e H a m ilto n ia n v a n is h . U n lik e T e w a r i's w o rk , th e c a l ­

c u la t io n s re p o r te d here a re e x a c t. A l l 1 - p a r t i c le / l - h o le

e x c i ta t io n s w ith K=0, and th o se 2 - p a r t ic le /2 - h o le c o n f ig u ra ­

t io n s w h ich have maximum o v e r la p w ith these and th e HF s ta te

a re c o n s id e re d . The H a m ilto n ia n m a tr ix is c a lc u la te d and

d ia g o n a liz e d in th e f u l l space o f these e x c i ta t io n s . The

e xa c t p a r t ic le - h o le m ix tu re s a re th u s o b ta in e d . We may, from

t h i s , conc lude how s ta b le th e HF s o lu t io n s a re w i th in th e

26 - 1 d s h e l l , what th e c o r re c t io n s to th e lo w -o rd e r q u a s i-

r o ta t io n a l band sh o u ld be , and w he the r o r n o t p a r t ic le - h o le

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85

e x c i ta t io n s accoun t f o r th e e x c ite d s ta te s above th e HF

q u a s i- r o ta t io n a l band.

2. H a rtre e -F o c k E q u a tio n s

The n u c le a r H a m ilto n ia n may be w r i t t e n , in th e n o ta t io n

o f second q u a n t iz a t io n , In term s o f any com plete o r th o n o rm a l

s in g le - p a r t ic le b a s is {<J>}, such as th e s h e l l model wave fu n c ­

t io n s | i n j - j c o u p lin g :

H ‘ + I (IV'1)k#H

where <<J> 1114>j > a re m a tr ix e lem ents o f th e one-body o p e ra to r

w h ich i s a sum o f th e k in e t ic e n e rg y , th e harm onic o s c i l l a t o r

energy and I 2 and ! • s fo rc e s ; |V | a re a n tis y m m e tr iz e d

m a tr ix e lem ents o f th e e f f e c t iv e tw o-body in t e r a c t io n , i s

th e fe rm io n c re a t io n o p e ra to r a s s o c ia te d w ith th e s in g le ­

p a r t i c le s ta te <f> ; i t obeys th e a n tic o m m u ta tio n ru le s

t a i ,a j-*+ = 6i j » [ > i> ajJ + = 0 •

E s s e n t ia l ly HF th e o ry seeks a p a r t ic u la r u n i ta r y t r a n s ­

fo rm a tio n from th e b a s is { } to a n o th e r com plete o rth o n o rm a l

b a s is { X>, in w h ich th e HF wave fu n c t io n 4 ^ is d e f in e d as

a S la te r d e te rm in a n t o f A o f th e fu n c t io n s X , known as th e

"o c c u p ie d " o r b i t s , where A i s th e number o f nuc leons b e in g

c o n s id e re d . The t ra n s fo rm a t io n to th e new b a s is i s g iv e n by^

XX = ^ c I 4.± . ( IV -2 )

L a t in in d ic e s a re used f o r th e b a s is {$ } and Greek in d ic e s f o r th e b a s is { X} .

Page 128: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

I f re p re s e n ts th e fe rm io n c re a t io n o p e ra to r a s s o c ia te d

w ith th e p a r t i c l e s ta te x ^ , th e n I t may im m e d ia te ly be seen

th a t

- I « i * I

and

''HP = bt bT • • - bA l 0>* ( IV - 3)

where |0> i s th e vacuum s ta te . The o r th o n o rm a lity o f th e

b a s is { X> im p lie s

<XA I Xy > = ]• ° i c i 6Xy »

where e x p l i c i t use has been made o f th e o r th o n o rm a lity o f th e

b a s is {<|>}. The b a s is { X} i s chosen so as to g iv e a s ta t io n a ry

and minimum f o r th e HF energy ERF o f th e system d e s c r ib e d by

th e wave fu n c t io n

86

The p rim e s in d ic a te th a t o n ly th e "o c c u p ie d " o r b i t s a re i n ­

c lu d e d in th e sum m ations. Ejjp may be expressed in term s o f

th e c o e f f ic ie n t s c ^ :

The s ta t io n a r y s o lu t io n s o f e q u a tio n ( IV - 5 ) , f o r a r b i t r a r yX*i n f i n i t e s im a l v a r ia t io n s o f th e c o e f f ic ie n t s ci , may be found

Page 129: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

n o t in g th e o r th o n o rm a lity o f th e b a s is (x > , by s o lv in g th e

e q u a tio n

TTv* CeHF - V I cj * cJ " 1 ) ] = °*OC J

where ev is in tro d u c e d as a Lagrange m u l t i p l i e r . P e rfo rm in g

th e d i f f e r e n t ia t io n o b ta in s a s e t o f homogeneous e q u a tio n s

f o r th e Cj c o e f f ic ie n t s :

IC«J>i | t|<j>J > + r < * i X x | V | V x > ] c ” = e v c ^ # ( I V - 6 )j X *

where th e m a tr ix e lem ents l v l a re d e fin e d by

<*1XX|V |* J XX> - « *1* k |T |+ J * 1» 0A . (XV-7)

D e f in in g th e HF H a m ilto n ia n h by i t s m a tr ix e le m e n ts :

= <<l>i | t |<|>j> + I <<J>i x x IV | Xx> , ( IV -8 )X

e q u a tio n ( IV - 6 ) becomes

- ev c i

o r e q u iv a le n t ly

* l x v> * ev lxv> • ( iv -9)Thus, th e HF o r b i t a ls a re e ig e n fu n c t io n s o f th e HF H a m ilto n ia n

The H a m ilto n ia n ft, w h ich is re p re s e n ta t iv e o f th e deform ed

f i e l d , may be e i t h e r phenom eno log ica l o r c a lc u la te d e x p l i c i t l y

as in e q u a tio n ( IV - 8 ) . The cho ice o f a deform ed harm onic

o s c i l l a t o r w ith a s p in - o r b i t and £ 2 c o r re c t io n

ft e V2 + [ w 2 x 2 w 2t /2+ w 2 z 2 ] + a t « s + Dt 2 ( I V - 1 0 )2m 2m A y z

87

Page 130: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

88

has o f te n been made. The s p in - o r b i t and Z z c o n t r ib u t io n s

a r is e q u ite n a tu r a l ly from a c o n s id e ra t io n o f th e te rm 7 2 in

a c o l le c t iv e tre a tm e n t o f a n u c le a r co re ( v . e q u a tio n ( A - I I - 1 0 ) ) .

Expand ing 7 2=( ^ +s ) 2 y ie ld s an Z2 te rm , an Z-s te rm , and an s 2 ^ 2

te rm , s b e in g a c o n s ta n t, can be ig n o re d . Assuming a x ia l

sym m etry, a>=wx =Uy, and a llo w in g f o r se p a ra te pa ram ete rs a and

D in th e H a m ilto n ia n ( IV -1 0 ) , r a th e r th an th e f ix e d r a t i o 2 ,

o b ta in s th e N ils s o n 11* o r b i t s ( IV - 9 ) . Newton16 re la x e d th e

assum p tion o f a x ia l sym m etry, b u t m a in ta in e d a and D as se p a ra te

p a ra m e te rs .

The expans ion ( IV -2 ) o f th e o r b i t a l s , in g e n e ra l, c o n ta in s

v e ry many te rm s . F o r d e fo rm a tio n s w h ich a re n o t to o la r g e ,

th e b a s is {<(>} may be chosen as s h e l l model wave fu n c t io n s

b e lo n g in g to one m a jo r s h e l l ; any e x t r a - s h e l l e f fe c ts th e re

m ig h t be a re e i t h e r n e g le c te d o r assumed to be p a r t i a l l y i n ­

c lu d e d in th e one-body fo r c e . In h e re n t in t h is ch o ice a re

th e assum ptions th a t th e in n e r core rem ains i n e r t , and th a t

p a r t i c l e e x c i ta t io n s to h ig h e r s h e l ls a re r e la t i v e l y un im por­

t a n t . I t i s s ig n i f i c a n t th a t th e HF energy ( IV -4 ) is th e

o n ly q u a n t i ty w h ich i s s ta t io n a r y w ith re s p e c t to s m a ll v a r i ­

a t io n s in th e o r b i t a ls ( x ) . T r a n s it io n and m u lt ip o le moments

a re v e ry s e n s it iv e to s l ig h t a d m ix tu re s to th e wave fu n c t io n s

fro m e i t h e r p o la r iz a t io n s o f th e core o r p a r t i c le e x c ita t io n s

in t o h ig h e r s h e l ls . The r e s t r i c t i o n o f th e p a r t i c le b a s is

to a s in g le m a jo r s h e l l may, th e re fo r e , p re c lu d e a f u l l un d e r­

s ta n d in g o f these phenomena.

Page 131: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

89

E q u a tio n s ( IV -8 ,9 ) a re g e n e ra lly r e fe r r e d to as th e

H a rtre e -F o c k e q u a tio n s . They a re so lv e d by th e fo l lo w in g

i t e r a t i o n p ro c e s s : An i n i t i a l guess i s made f o r th e HF

o r b i t a ls ( IV - 2 ) . These o r b i t s a re used in e q u a tio n ( IV -8 )

d ia g o n a l iz a t io n , gene ra tes a new s e t o f HF o r b i t s . Thr>

H a m ilto n ia n i s th e n re c a lc u la te d w ith th e new o r b i t s , and

so on , u n t i l su cce ss ive d ia g o n a liz a t io n s y ie ld th e same b a s is .

The method does n o t y ie ld a un ique s o lu t io n because o f th e

n o n - l in e a r i t y o f e q u a tio n s ( IV - 8 ,9 ) , and th e re may be s e v e ra l

lo c a l m inim a on th e energy s u r fa c e ( IV - 4 ) . D i f f e r e n t lo c a l

m in im a may be reached by v a r io u s i n i t i a l guesses o f th e

o r b i t a ls ( IV - 2 ) . T h is amounts to b e g in n in g a t d i f f e r e n t p o in ts

on th e m u lt i-d im e n s io n a l energy s u r fa c e . The ch o ice o f t h is

s t a r t in g p o in t i s th u s c r u c ia l . One g e n e ra lly has to search

f o r th e s o lu t io n w h ich g iv e s an a b s o lu te minimum f o r th e HF

e n e rg y .

Once th e b a s is ( x ) i s d e te rm in e d , th e HF energy may be

c a lc u la te d by expand ing th e HF s in g le - p a r t ic le energy e ig e n ­

va lu e s e ^ :

The m a tr ix e lem ents o f th e HF H a m ilto n ia n h a re g iv e n in

e q u a tio n ( IV - 8 ) ; th u s

to c a lc u la te th e H a m ilto n ia n m a tr ix <<1 1 h I w h ich th ro u g h

eX

The HF energy i s e a s i ly seen to become

( I V - 12)

Page 132: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

90

A t each s te p o f th e i t e r a t i o n p ro c e s s , i t must be

d ec ide d w h ich o r b i t s a re to be c la s s i f ie d as "o c c u p ie d " .

T h is i s g e n e ra lly done by e v a lu a t in g e q u a tio n ( IV -1 1 ) f o r

a l l a llo w e d va lu e s o f X. The A o r b i t s h a v in g th e lo w e s t

e ig e n va lu e s e^ a re chosen to be o ccu p ie d .

I t i s to be n o te d th a t unoccup ied o r b i t a ls and t h e i r

e n e rg ie s a re a ls o o b ta in e d by b r in g in g A to a d ia g o n a l fo rm .

I t sh o u ld n o t be conc luded th a t th e nu c leus o f odd mass A + l

can be t re a te d by c o n s id e r in g th e la s t n u c le on in th e v a r io u s

unoccup ied p a r t i c le o r b i t a ls g e n e ra te d s e l f - c o n s is t e n t ly by

th e f i r s t A n u c le o n s . C le a r ly , such a model w ould n e g le c t

a l l rea rrangem en t o f th e i n t r i n s i c co re s t r u c tu r e produced

by th e tw o-body in te r a c t io n s between th e co re nuc leons and

th e odd one. M oreove r, th e s t re n g th o f t h is p o la r iz a t io n

depends on w h ich le v e l th e la s t n u c le on o c c u p ie s .

3. Sym m etries o f th e H a rtre e -F o c k S o lu t io n s

The s o lu t io n o f th e HF e q u a tio n s ( IV -8 ,9 ) o b ta in s an

o rth o n o rm a l b a s is o f e ig e n s ta te s (x ) o f th e H a m ilto n ia n h .

Not a l l o f th e se s ta te s a re occup ied by n u c le o n s— o n ly those

s ta te s a p p e a rin g in th e d e f in i t i o n ( IV -2 ) o f Any

p a r t ic u la r s o lu t io n o f th e HF e q u a tio n s depends upon th e

ch o ice o f w h ich s ta te s a re to be o cc u p ie d , b o th i n i t i a l l y

and d u r in g th e i t e r a t i o n p ro c e s s . A l te r n a t iv e s o lu t io n s ,

n o t n e c e s s a r i ly o r th o g o n a l, may be g e n e ra te d by occupy ing

d i f f e r e n t s ta te s a t any p o in t in th e i t e r a t i o n p ro ce ss .

Page 133: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The HF H a m ilto n ia n does n o t a p t iio t u . e x h ib i t th e same

symmetry p ro p e r t ie s as the n u c le a r H a m ilto n ia n ( IV —1 ) ; n o r

i s a g iv e n symmetry n e c e s s a r ily p re se rve d in su cce ss ive

i t e r a t io n s . N e v e rth e le s s h may share some symmetry p ro p e r t ie s

w ith th e n u c le a r H a m ilto n ia n , depending upon th e p a r t ic u la r

ch o ice o f o ccu p ie d o r b i t s . Tq u n de rs ta nd t h is phenomenon, we

c o n s id e r an o p e ra to r ft w h ich commutes w ith th e n u c le a r H a m il­

to n ia n H

[H , f t ] = 0 ,

and l e t {A } be th e s e t o f o ccup ied HF o r b i t s , i . e . , th e s e t

(A ) be longs to th e s e t o f HF o r b i t s ( x K I f ft leave s th e

s e t {A } in v a r ia n t

ft{A ) = {A } ( IV -1 3 )

th e n th e HF H a m ilto n ia n h w i l l commute w ith ft

[A , f t ] = 0 .

F o r exam ple, i f ft i s a one-body o p e ra to r , e q u a tio n ( IV -1 3 )

im p lie s th a t th e s ta te o b ta in e d by o p e ra t in g w ith ft on an

o ccup ie d o r b i t may be expressed as a l in e a r co m b in a tio n o f

o ccup ie d o r b i t s o n ly :

ftA = y w A ,P { yv v ’

where a re th e m a tr ix e lem ents

" i i v = •

The m a tr ix e lem ents <Xv lnl^p> va n is h id e n t i c a l l y i f xv does

n o t b e lo n g to th e s e t {A } . I f ft o p e ra te s on th e HF s ta te ,

i t w i l l have no e f f e c t o th e r th a n m u l t ip l i c a t io n by a c o n s ta n t,

i . e . , i s an e ig e n s ta te o f ft:

91

Page 134: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Thus, f o r exam ple, th e o r b i t s ( IV -2 ) a re e ig e n s ta te s o f J_ .zT h e re fo re J leave s th e s e t o f occup ied o r b i t s in v a r ia n t , z

The o p e ra to r R ( tt) = e x p ( - i ir J ) p e rfo rm s a r o ta t io n o fV J

tt ra d ia n s abou t th e y - a x is . W ith each o r b i t x Is a s s o c ia te d

th e o r b i t X

|X> = Rv ( tt) | X>_y ( IV -1 4 )

Ry( it) |X> = - |x> •

When b o th o r b i t s x and x ar® o ccu p ie d , R ( tt) le a ve s th eys e t (X ) o f occu p ie d o r b i t s in v a r ia n t . T h e re fo re k commutes

w ith R ( t t ) , and th e HF s o lu t io n f o r even-even n u c le i mayv

possess th e symmetry

Ry ^ I'I'h f> = I^HF* *

N e x t, we l e t th e HF o r b i t s be e ig e n s ta te s o f J 2 and

^ z * i , e * » , .X = I

J 2X = j l j + U x

j zX = mx •

Then h w i l l commute w ith J o n ly i f 3” le a ve s th e s e t {X}

in v a r ia n t . S ince j and j m ix s ta te s o f d i f f e r e n t m, th ex ys e t w i l l rem a in in v a r ia n t o n ly i f a l l p o s s ib le m -s ta te s f o r

a g iv e n j a re o ccu p ie d . Such a s ta te is a c lo s e d s h e l l .

F in a l l y , we c o n s id e r n e u tro n -p ro to n exchange o p e ra to rs .

I f a n u c le u s has an e q u a l number o f p ro to n s and n e u tro n s , a

HF s o lu t io n e x is ts f o r w h ich n e u tro n s and p ro to n s a re in th e

same o r b i t s . The th re e components o f th e t o t a l is o s p in ope ra ­

t o r w i l l th e n le a ve th e s e t {X } o f o ccu p ie d o r b i t s in v a r ia n t .

Page 135: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

N e g le c tin g th e Coulomb in t e r a c t io n , th e HF f i e l d i s an is o ­

s p in s c a la r , n e u tro n and p ro to n o r b i t s a re d e g e n e ra te , and

th e HF s ta te has ze ro is o s p in .

I t s h o u ld , how ever, be s tre s s e d , th a t a lth o u g h a s o lu ­

t io n o f th e HF e q u a tio n s ( IV -8 ,9 ) may e x h ib i t a g iv e n sym­

m e try , t h is need n o t be th e lo w e s t s o lu t io n . There may be

a n o th e r s o lu t io n w ith lo w e r energy w ith o u t t h is p a r t ic u la r 28sym m etry. S i , f o r exam ple, has a s p h e r ic a l s o lu t io n c o r ­

re sp o n d in g to th e c lo s u re o f th e ^ 5 / 2 ( ° f * s e c t io n28IV .6 d ) . Yet deform ed s o lu t io n s e x is t f o r S i w ith lo w e r

e n e rg y . In g e n e ra l, th e r e la x a t io n o f a symmetry c o n d it io n ,

in fa v o r o f a le s s r e s t r i c t i v e c o n d it io n , low e rs th e HF

e n e rg y , th e symmetry energy no lo n g e r b e in g in c lu d e d .

4 . H a rtre e -F o c k C a lc u la t io n s

The b a s is { <t>} on w h ich th e HF o r b i t a ls ( x ) a re expanded

(e q u a tio n ( IV - 2 ) ) i s , in th e o ry , a r b i t r a r y . However,- in

r e a l i t y , such im p o rta n t fa c to r s as th e convergence o f the

s o lu t io n s , th e conven ience o f c a lc u la t in g m a tr ix e lem ents o f

th e tw o-body in t e r a c t io n , and th e sym m etries o f th e HF f i e l d ,

impose r e s t r i c t io n s upon th e ch o ice o f b a s is fu n c t io n s . The

convergence p rob lem has been s tu d ie d . f o r s p h e r ic a l c lo s e d -

s h e l l n u c le i , and harm onic o s c i l l a t o r o r b i t s were found to

g iv e e x c e l le n t co n ve rg e n ce .58 Thus, harm onic o s c i l l a t o r wave

fu n c t io n s w i l l be used f o r th e r a d ia l p a r t o f th e b a s is {<J>}.

S h e ll model s ta te s \ n t j m r > a re used f o r th e a n g u la r - s p in - is o -

s p in p a r ts because o f th e conven ience o f o b ta in in g m a tr ix

93

Page 136: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

S in g le - p a r t ic le e n e rg ie s o b ta in e d 59 from p icku p e x p e r i- 40ments on Ca a re s l i g h t l y ' d i f f e r e n t from those o b ta in e d

17from th e 0 spec trum . I t sh o u ld be rea so n a b le to e x tra p o la te

f o r in te rm e d ia te n u c le i . These e n e rg ie s , to g e th e r w ith th e

o s c i l l a t o r c o n s ta n ts d e r iv e d from e le c t ro n s c a t te r in g 60 a re

p re se n te d in T ab le V I I I . T h is method has th e advantage o f

g iv in g and Ca**^ e q u a l ro le s as re fe re n c e n u c le i .

The tw o-body in t e r a c t io n used is th e Gaussian p o te n t ia l

w ith a R o s e n fe ld 61 exchange m ix tu re :

2 . 2 "*■V = V e " r / y IjlaL z . [ o .3 + 0 .7<*i *<*2 ] . ( IV -1 5 )

0 3

T h is i s a p a r t i c u la r l y u s e fu l in t e r a c t io n because o f th e

ease w ith w h ich i t s m a tr ix e lem ents a re c a lc u la te d . I t

w i l l be shown th a t th e space exchange component o f th e i n ­

te r a c t io n g iv e s r is e to energy gaps in th e HF s in g le - p a r t ic le

s p e c tra , w h ich a re necessa ry f o r H a rtre e -F o c k to be a v a l id

a p p ro x im a tiv e te c h n iq u e .

R ip k a 25 has s o lv e d th e HF p rob lem as d e s c rib e d above w ith

th e assum ptions o f t im e r e v e r s a l, is o to p ic s p in , and a x ia l

sym m e tries . The r e s u l t in g s in g le - p a r t ic le s p e c tra and e ig e n ­

fu n c t io n s a re p re se n te d in F ig u re 15 and T ab le IX , r e s p e c t iv e ly .24When th e r e s t r i c t i o n to a x ia l symmetry was re la x e d , Mg and

S32 were found to have t r i a x i a l s o lu t io n s 3-** MeV (b e fo re

p r o je c t io n ) lo w e r th a n th e a x ia l l y sym m etric s o lu t io n s . The

n a tu re o f these s o lu t io n s w i l l be d iscu sse d la t e r in t h is sec­

t io n (see a ls o s e c t io n s IV .6 c ,e ) .

94

elements of the two-body Interaction.

Page 137: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T ab le V I I I V a lues o f o s c i l l a t o r c o n s ta n t a and o f th e s in g le - p a r t ic le e n e rg ie s e . uped in s in g le m a jo r s h e l l HF c a lc u la t io n s w ith a R o se n fe ld exchange c h a r a c te r is t ic

.Nucleus a ( fm“ 1) 5/2(MeV)

* * 1 / 2(MeV)

3/2(MeV)

VO i—io 0 .568 -4 .1 4 -3 .2 7 0 .93

He20 0.559 -4 .3 8 -3 .2 6 0 .79

Mg2*1 0.547 -4 .7 1 -3 .2 6 0 . 6 1

COCM•HCO 0 .548 -4 .6 8 -3 .2 6 0 .62

S32 0.531 -5 .1 4 -3 .2 5 0 .36

A r^ 6 0.496 -6 .0 9 -3 .2 2 -0 .1 9

Ca4° 0.492 -6 .1 9 -3 .2 2 -0 .2 5

\

Page 138: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F ig u re 15. S in g le - p a r t ic le e n e rg ie s ev o b ta in e d from s in g le m a jo r s h e l l HF c a lc u la t io n s w ith a R o se n fe ld exchange ch a ra c ­t e r i s t i c f o r even-even N=Z n u c le i in th e 26 - 1 d s h e l l . The s p e c tra shown a re f o r th e lo w e s t a x ia l l y sym m etric s o lu t io n s in each case . Shown to th e r ig h t o f each s in g le p a r t i c le le v e l i s th e a n g u la r momentum p r o je c t io n o n to th e a x is o f sym m etry, and th e p a r i t y . The I p s h e l l o r b i t s have n e g a tiv e p a r i t y , and th e 2 6 - I d o r b i t s have p o s i t iv e p a r i t y . The Ferm i s u r fa c e and i p s h e l l c lo s u re s a re in d ic a te d . A lso shown a re th e Ferm i le v e ls f o r th e lo w e s t t r i a x i a l s o lu t io n s o f Mg24 and S32 .

Page 139: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SIN

GL

E-P

AR

TIC

LE

EN

ERG

Y (M

eV)

-5

-10

-15 -

-2 0

-25 -

-30

-35 -

-40

DEFORMED PARTICLE E IGENVALUES

3/2 ' +

1/2"+

.5 /2 + l / 2 ' +

•3 /2 +

•3/2'+

■1/2"+

•5 /2+

•1/2’ + :

■1/2" +

. 1/2' + ’3/2'+ .1/2"+

'3 /2 ‘+ 1/2"+ELLIPSOIDAL

-3 /2 + FERMI LEVELS

\ 5/2+

3 /2 + y W l /2 ‘+ / / / ' |/2' +

AXIALLY SYMMETRIC FERMI LEVEL

•P SHELL CLOSURE

Ne 2 0 Mg24 Si 28 "32 Ar 36

Page 140: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T ab le IX - A x ia l ly sym m etric HF s o lu t io n s w ith a Gaussian tw o-body in t e r a c t io n and R o se n fe ld exchange c h a r a c te r is t ic . The u n d e r lin e d numbers a re th e e n e rg ie s ev and z - p ro je c t io n s o f p a r t i c le a n g u la r momentum o n to th e symmetry a x is o f th e HF o r b i t s . The energy o f each o r b i t i s fo llo w e d by expans ion c o e f f ic ie n t s c^ f o r th a t o r b i t ( v . e q u a tio n ( IV - 2 ) ) . The s ix s ta te s a re p o s i t iv e p a r i t y 26 - 1 d s h e l l o r b i t s . The

k = l /2 p o s i t iv e p a r i t y o r b i t s a re fo llo w e d by t h e i r components

on th e 6 1 /2 * and d l / 2 s ta te s > in o rd e r . Thek= 3 /2 p o s i t iv e p a r i t y o r b i t s a re fo llo w e d by t h e i r components

on th e ^ 3 / 2 and d3 /2 s ta te s * The k =5 /2 p o s i t iv e p a r i t y o r b i t s have no in d ic a te d com ponents, and th e y a re pure s ta te s . The la s t l in e g iv e s th e HF energy E^p in MeV. A s te r is k s in d ic a te w h ich o r b i t s a re o ccu p ie d .

Page 141: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Table IX - Axially Symmetric HF Solutions

Ne20 Mg24 S i 2 8 ( p r o l ) S i 2 8 ( o b l ) S3 2 ( o b l ) S3 2 ( p r o l ) Ar36- 1 4 . 5 8 * ’ - 1 6 . 2 5 * - 1 9 . 3 7 * - 1 8 . 5 3 * - 1 7 . 9 5 * - 1 9 . 7 4 * - 2 0 . 9 2 *( k = l / 2 ) ( k = l / 2 ) ( k = l / 2 ) ( k = 5 /2 ) ( k = l / 2 ) ( k = l / 2 ) ( k = 5 / 2 )- 0 . 7 5 7 6 - 0 . 7 9 0 4 - 0 . 7 7 6 3 - 0 . 7 5 3 6 - 0 . 8 8 5 6

0 . 5 2 7 3 0 .5 45 2 0 .6 1 8 8 - 1 7 . 9 8 * - 0 . 5 9 0 4 0 .4 6 4 1 - 1 9 . 7 8 *0 .3 8 4 7 • 0 .2 7 9 4 0 . 1 2 0 3 ( k = l / 2 ) 0 . 2 8 9 1 0 .0 20 3 ( k = 3 / 2 )

- 6 . 5 8 - 1 1 . 9 4 * - 1 7 . 5 3 * - 0 . 5 7 8 3- 0 . 7 5 9 6

0 : 2 9 7 7

- 1 7 . 6 1 * - 1 9 . 9 1 * 0 .9 9 4 1( k = 3 / 2 ) ( k = 3 / 2 ) ( k = 3 /2 ) ( k = 5 / 2 ) ( k = 3 / 2 ) 0 .1 0 8 4

- 0 . 9 9 3 2 - 0 . 9 7 0 6 - 0 . 9 5 3 1 . - 0 . 9 7 5 3 - 1 8 . 8 0 *0 . 1 1 6 7 0 .2 4 0 6 0 .3 0 2 7 - 1 4 . 9 9 * - 1 6 . 4 8 * 0 .2 20 9 ( k = l / 2 )

0 . 8 0 5 40 . 5 8 7 30 . 0 8 0 1

( k = 3 /2 ) ( k = l / 2 1)- 5 . 1 9 - 9 . 8 1 - 1 4 . 6 7 * 0 .6 9 3 5 - 0 . 5 6 5 5

0 .8 0 6 4- 1 5 . 5 1 *

( k = l / 2 » ) ( k = l / 2 *) ( k = l / 2 1) 0 .7 20 4 ( k = l / 2 ' )- 0 . 6 3 5 7 - 0 . 5 4 3 6 - 0 . 4 5 7 2 - 8 . 3 2

( k = 3 / 2 ' )0 . 1 7 2 9 - 0 . 2 9 8 5

- 0 . 7 2 9 8 - 0 . 4 1 3 9 - 0 . 4 2 1 2 - 0 . 5 3 5 0 - 1 5 . 8 3 *- 0 . 2 5 1 6 - 0.7302 - 0 . 7 8 3 3 - 1 5 . 0 7 * - 0 . 7 9 0 3 ( k = l / 2 1)

0 .7 20 4 ( k = 3 / 2 )- 0 . 4 3 9 3

0 .6 8 2 2- 0 . 5 8 4 4

- 5 . 1 4 ( k = 5 / 2 )

- 7 . 5 0 ( k = 5 /2 )

- 9 . 2 6 ( k = 5 /2 )

- 0 . 6 9 3 5

- 8 . 1 10 . 9 0 8 10 .4 1 8 7

- 1 4 . 3 3 * ( k = 5 / 2 )

- 2 . 3 5 - 4 . 89 - 6 . 5 0 ( k = l / 2 ' )- 1 1 . 3 7 - 1 0 . 2 3 - 1 4 . 7 4 *

( k = l / 2 " ) ( k = l / 2 " ) ( k = l / 2 " ) 0 .8 04 4 ( k = 3 / 2 ’ ) ( k = 3 / 2 1) ( k = 3 / 2 » )- 0 . 1 4 8 1 0 .2 82 5 0 .4 3 4 0 - 0 . 4 7 0 2

0 .3 6 3 0 0 .4 1 8 7 0 .2 20 9 0 .1 0 8 4- 0 . 9 9 4 10 . 4 3 5 1 0 .7 29 0 0.6630 - 0 . 9 0 8 1 0 .9 7 5 3

- 0 . 8 8 8 1

- 0 . 2 5

- 0 . 6 2 3 5

- 2 . 9 9

- 0 . 6 0 9 9

- 4 . 7 0- 4 . 1 0 ( k = l / 2 " ) - 1 0 . 0 3

( k = l / 2 " )- 1 0 . 0 3( k = l / 2 " )

- 1 0 . 1 4 ( k = l / 2 " )

( k = 3 / 2 ’ ) ( k = 3 / 2 ' ) ( k = 3 / 2 ’ ) 0 . 1 358 0 .3 3 5 2 0 . 355 9 0 .3 9 7 90 .1 16 7 0 .2 40 6 0 .3 0 2 7 - 0 . 4 4 9 4 0 .0 3 3 2 0 .7 06 0 - 0 . 4 3 5 50 .9 9 3 2 0 .9 706 0 .9 5 3 1 - 0 . 8 8 3 0 0 .9 41 6 - 0 . 6 1 2 3 - 0 . 8 0 7 5

p - 3 5 . 7 8 - 7 2 . 9 1 - 1 2 2 . 0 1 - 123.00 - 1 6 8 . 4 4 - 168.80 - 2 2 0 . 4 8

Page 142: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The a p p l ic a t io n o f p r o je c t io n o p e ra to rs to th e HF

s ta te ( IV -3 ) gen e ra te s a q u a s i- r o ta t io n a l s e r ie s in deform ed

n u c le i . The n u c le a r s ta te s w ith d e f in i t e a n g u la r momentum

p re d ic te d by th e HF model may be d e s c rib e d by a p ro d u c t wave

fu n c t io n in w h ich r o t a t io n a l m o tion is d is t in g u is h e d from

i n t r i n s i c m o tio n ( c f . Appendix A - I I ) :

95

2 J + 1 V 216 ir ‘

where M i s th e p r o je c t io n o f J in th e la b o ra to ry fra m e , t h is

s ta te b e lo n g in g to a r o t a t io n a l band ge n e ra te d by a deform ed

in t r i n s i c s ta te |i|> > , w h ich has a x ia l symmetry and p r o je c t io n- K

K o f J o n to th e z -a x is o f th e i n t r i n s i c fra m e , and i|> =

e x p ( - iu J )i|>K.«/

An a l t e r n a t iv e way o f d e s c r ib in g t h is s ta te i s by th e

p r o je c t io n method in tro d u c e d in s e c t io n I I . 2 . U t i l i z i n g

e q u a tio n s ( I I - 5 ) . ,

" ~ T ~ ~ ,

where

n j k c f d Q V K K Cn)<ipK | r ( n ) k K> .S IT2

Because o f th e assum ption o f a x ia l sym m etry, th e HF s ta te

JJKi s an e ig e n s ta te o f J . The n o rm a liz a t io n in t e g r a l N?

reduces to

NJK ■ /d B s in ( B ) d ^ 6 l< > ( > K | e “ i p J y |<eK> , ( I V - 1 6 )

where

dMK{01 = <JM|e”16Jy | JK> . (IV-17)

Page 143: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

96

S im i la r ly , th e e n e rg ie s o f th e q u a s i- r o ta t io n a l band, genera ­

te d by th e HF s ta te , a re g iv e n by

T IS “ i8«J IS

/ y .B in e d ^ ( e i < 4 l e ■ yH | * S _ ( I V _ l 8 )

hJ = --------------------------------------------------- :---------T V - i8 J y

/ d8 s inB d ^ { Q ) < ] p |e y |i|» >

P a r t ia l p ro je c te d s p e c tra o b ta in e d by R ip k a 25 in t h is way f o r20 28 -jfi

Ne , S i , and A r a re p re se n te d in F ig u re 16, to g e th e r

w ith th e lo w -e n e rg y p o s i t iv e p a r i t y e x p e rim e n ta l s p e c tra o f

th e se n u c le i .20As can be r e a d i ly seen, th e s o lu t io n is f a i r f o r Ne ,

b u t p o o r f o r th e o th e r n u c le i shown. T h is may be p a r t ly

u n d e rs to o d fro m an e xa m in a tio n o f th e s in g le p a r t ic le s p e c tra

(F ig u re 15) (see a ls o s e c t io n I V . 6 ) . In s p ite o f th e fa c t

th a t th e wave fu n c t io n o f th e Ferm i le v e l i s unde rg o ing con­

t in u a l change from n u c leu s to n u c le u s , th e e x c i ta t io n energy+

o f th e Ferm i le v e l rem a ins a p p ro x im a te ly c o n s ta n t. The

energy gap between occup ied and unoccup ied o r b i t s , how ever,20f a l l s o f f r a p id ly a f t e r Ne ( v . s e c t io n IV .5 a ) .

To u n d e rs ta n d th e o r ig in o f these phenomena, we c o n s id e r

th e expans ion o f th e s p a t ia l p a r t o f a tw o-body p o t e n t ia l in

te rm s c o rre s p o n d in g to d e c re a s in g ra n g e 52. T h is has a lre a d y

been d iscu sse d in s e c t io n I I I . 3 , in c o n n e c tio n w ith th e phe-

+ 24The n o ta b le e x c e p tio n is Mg , w h ich has a Ferm i le v e la p p ro x im a te ly 2 .5 MeV above th e o th e rs . T h is i s due to th e f a c t th a t th e a x ia l s o lu t io n p re se n te d here is n o t th e lo w e s t s o lu t io n ; th e lo w e s t energy s o lu t io n s o f Mg24 and S3 2 a re t r i a x i a l . The Ferm i le v e ls f o r these s o lu t io n s a re a ls o i n ­c lu d e d in F ig u re 15, and dem onstra te th e c o n s ta n t e x c i t a t io nenergy o f th e le v e ls q u ite w e l l .

Page 144: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F ig u re 16. P ro je c te d H a rtre e -F o c k s p e c tra o f Ne^9 , S i^ 3 , and A r3A The number to th e r ig h t o f each le v e l i s th e s p in o f th e s ta te . The lo w -e n e rg y p o s i t iv e p a r i t y e x p e r im e n ta l spectrum is drawn to th e l e f t in each case. Is o s p in a s s ig n ­ments a re a l l z e ro , excep t when in d ic a te d as J ( T ) .

Page 145: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

EX

CIT

ATI

ON

EN

ERG

Y (M

eV

)

[10

Ne20 S i28 A r 36

12 1 — 8

-6^2'0

8 ---------8

^2(1)"3(1)

46 ,3

‘68 | - 2 -2 8

•4■0•3

0>0 2

■ — — I

EXPT PROJ EXPT PROJ EXPT PROJ

Page 146: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

n o m e n o lo g ica l in te r a c t io n used in th e ( / ) w c a lc u la t io n s .

The le a d in g te rm , o f zero o rd e r , i s s im p ly a c o n s ta n t. The

n e x t te rm o f im p o rtan ce is th e q u a d ru p o le -q u a d ru p o le fo rc e

o f s e c t io n I I I . 3 , w h ich is re p re s e n ta t iv e o f the lo n g range

p a r t o f th e n u c le a r fo r c e . The f i r s t te rm , VQ, a c o n s ta n t

p o te n t ia l w ith no s p a t ia l dependence, has o n ly an exchange

c h a r a c t e r is t ic , w h ich may g e n e ra lly be w r i t t e n as

VQ = W + BPa + HPt + MPX ( IV -1 9 )

where Pa , P^, and Px a re th e s p in , is o s p in , and p o s i t io n

exchange o p e ra to rs :

P = 1 + Q i • < * ,

0 " 2, ->■ -+ p - T ,

T 2

P = -P P x a x

and W (W ig n e r) , B ( B a r t l e t t ) , H (H e is e n b e rg ), and M (M a jo rana)

a re s t re n g th c o e f f ic ie n t s . F o r s im p l ic i t y , we l e t th e 2 6 - 1 d

s h e l l be degenera te in i t s s in g le p a r t ic le e n e rg ie s , e=ey.

The HF s o lu t io n s ( IV -2 ) may th e n be fa c to re d in t o se p a ra te

space , s p in , and is o s p in components:

IX * = I V I ° X> ITX> • ( IV -2 0 )

S ince VQ commutes w ith a l l s p a t ia l m o tio n s , th e HF H a m ilto n ia n

i s , o f c o u rs e , d ia g o n a l In any o rth o n o rm a l re p re s e n ta t io n o f

th e s p a t ia l wave fu n c t io n s . The m a tr ix e lem ents o f h (e q u a tio n

( IV - 8 ) ) become

e a =<V V rJ ' l K aa V

=<<Y V a I K ° a V + <ax V a : * x V XlV I V ’ a V V x V

97

Page 147: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

H ere , a g a in , p rim es in d ic a te summation o ve r occup ie d o r b i t s

o n ly .

The two term s in each b ra c k e t a re th e d i r e c t and exchange

c o n t r ib u t io n s . Depending upon th e ch o ice o f fu n c t io n s |X >,Ae i t h e r a x ia l l y sym m etric o r n o n - a x ia l ly sym m etric s o lu t io n s

/may be c o n s tru c te d . The o n ly c h a r a c te r is t ic o f im p o rta n ce

here is th e o v e r la p in te g r a ls «x |X > , w h ich a re e i t h e r zeroA Ao r u n i t y ; th e se term s cannot d e te rm in e th e s p a t ia l dependence

o f th e HF o r b i t a l s . F i l l i n g each o ccu p ied o r b i t |X > w ithAtwo n e u tro n s and two p ro to n s o f o p p o s ite s p in s , each o f th e

o ccu p ie d HF e n e rg ie s ( IV -2 1 ) ( f o r even-even N=Z n u c le i)

e. = e + ^ -G ( IV -2 2 a )X 2j

and th e unoccup ied o r b i t s

e = e + — ( IV -2 2 b )a ij

where A is th e number o f nuc leons b e in g c o n s id e re d , and

S = 4W + 2B + 2H - M( IV -2 2 c )

G = W + 2B + 2H -4M .

The degenera te o ccup ied o r b i t a ls a re th e re fo re depressed

r e la t i v e to th e degenera te unoccup ied o r b i t a ls by an energy

gap G, independen t o f th e number o f p a r t ic le s A. F o r th e

R o se n fe ld exchange m ix tu re ( IV -1 5 ) , S=0, im p ly in g a c o n s ta n t

Ferm i le v e l . The energy gap is thus d e te rm in ed by th e cornbin-

Page 148: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

a t io n G o f th e exchange m ix tu re , w h ich is dom inated by th e

M ajorana component o f th e in t e r a c t io n . T h e re fo re , a s tro n g

a t t r a c t iv e M ajorana fo r c e , fa v o r in g maximum s p a t ia l sym m etry,

w i l l p roduce a la rg e energy gap, and th e a tte n d a n t s ta b le HF

s o lu t io n s ( v . s e c t io n IV .5 a ) .

F o r a fo rc e o f a r b i t r a r y r a d ia l dependence, f i l l i n g each

o r b i t |X > w ith fo u r n u c le o n s , th e m a tr ix e lem ents o f th e HFA

H a m ilto n ia n ( IV -8 ) become

n n< a |h |B > = < a |t|& > + s £ < a X |V |3 X>n-GJ<aX|V|X$>n ( IV -2 3 )

X=1 v X=1 v

where n=A/4 re p re s e n ts th e number o f space o r b i t a ls |X >.AThe s u b s c r ip t D in d ic a te s th a t th e m a tr ix e lem ent i s th e

d i r e c t te rm

<aX | V | 8X>D = / d r 1d r 2<j)a* ( r 1)«J)A* ( r 2 ) V ( r 1 , r 2) ( r 2 )<j>x ( r 2) ,

( IV -2 4 )

T ra n s fo rm in g th e HF H a m ilto n ia n ( IV -2 3 ) to c o n f ig u ra t io n

space may be accom p lished o n ly a f t e r th e r e la t io n between

momentum-and c o n f ig u ra t io n -s p a c e wave fu n c t io n s is d e f in e d :

|a> = fdr<r|<{> ( r ) > | r > . ( IV -2 5 )vX

Then th e H a m ilto n ia n ( IV -2 3 ) may be w r i t t e n

<£ i l M ? 2> = - 6 ( r x- r 2) — + S 6 ( r 1- r 2 )/dr^|< j>x ( r ) | 2V ( r x , r )2 2m X=1 A

- ) V ( r x , r 2) . ( IV -2 6 )X

S i s th e in t e n s i t y o f th e lo c a l te rm o f th e HF f i e l d , and G

is th e in t e n s i t y o f th e n o n - lo c a l te rm . The m a n ife s ta t io n

99

Page 149: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

o f an energy gap in th e HF spectrum is th e re fo re a d i r e c t

consequence o f th e n o n - lo c a l i t y 6 f th e HF f i e l d .

A G aussian p o te n t ia l w ith R o se n fe ld exchange cha ra c­

t e r i s t i c s and v a n is h in g s p in - o r b i t s p l i t t i n g y ie ld s th e HFA l|

r e s u l t s 25 shown in F ig u re 17. In th e Mg a x ia l s o lu t io n ,

a n e u tro n and p ro to n a re p la c e d In th e d ^ f and o r b i t s .

In th e e l l i p s o id a l s o lu t io n , fo u r nuc leons f i l l th e same

s p a t ia l o r b i t . The e l l i p s o id a l s o lu t io n , w h ich has

lo w e r energy and a la r g e r gap th a n th e a x ia l s o lu t io n , has

maximum s p a t ia l sym m etry. T h e re fo re , in o rd e r o f p re fe r re d

sym m e trie s , a R o se n fe ld fo rc e p re fe rs HF s o lu t io n s w ith

maximum s p a t ia l symmetry to s o lu t io n s w ith a x ia l sym m etry.20 24Both a re co m p a tib le in Ne , b u t n o t in Mg . In th e p ro la te

p Os o lu t io n o f S i b o th th e (d ^ -d ^ ) and (d^+d ^ ) o r b i t s a re

f i l l e d . In t h is case , a x ia l symmetry is re s to re d because th e

o p e ra to r J s im p ly tra n s fo rm s one occu p ied o r b i t in t o a n o th e r zand le a ve s th e s e t o f occup ied o r b i t s in v a r ia n t ( c f . s e c t io n

I V . 3 ) . E s s e n t ia l ly , th e o b la te s o lu t io n may be o b ta in e d by

exchang ing empty and f i l l e d o r b i t s o f th e p r o la te s o lu t io n .

The two a re n e a r ly o r th o g o n a l and degenera te in th e HF

e n e rg ie s ( c f . s e c t io n IV .6 d ) .

The e x is te n c e o f o r th o g o n a l s o lu t io n s d e s c r ib in g d i f f e r -p O

e n t e q u i l ib r iu m shapes in S i is co n firm e d by th e re a c t io n

A l27(He3 ,p ) S i2 '*. M e y e r-S c h u tz m e is te r62 has found th a t th e

r e a c t io n c ro ss s e c t io n f o r a s ta te near 4 .7 MeV e x c i ta t io n29 29energy in S i i s v e ry much la r g e r th a n th a t f o r th e S i

ground s ta te . A ve ry l i k e l y e x p la n a t io n o f t h is phenomenon

1 00

Page 150: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

i s th a t th e 4 .7 MeV s ta te in S i2^ is a r e s u l t o f a n e u tro n

occu p y ing th e lo w e s t HF o r b i t a l a v a i la b le 1” in th e S i2® p r o la te27c o n f ig u r a t io n . S ince A l has a p r o la te e q u i l ib r iu m deform a­

t io n in th e ground s ta te 63, th e re a c t io n c ro ss s e c t io n f o r

the 4 .7 MeV s ta te s h o u ld , th e r e fo r e , be la r g e r th a n th a t f o r

th e ground s ta te , th e fo rm e r r e a c t io n b e in g shape c o n se rv in g

( c f . s e c t io n , IV .6 d ) .

Im p o rta n t e f fe c ts on th e HF wave fu n c t io n s a re i n t r o ­

duced by th e in c lu s io n o f an t*s s p in - o r b i t te rm in th e HF

H a m ilto n ia n . I t m ixes s ta te s w ith sp in s o f o p p o s ite s ig n s ,

so th a t th e o r b i t s cannot be fa c to r iz e d in t o space and s p in

p a r ts as in e q u a tio n ( IV -2 0 ) . I f th e s t re n g th o f th e s p in -

o r b i t te rm were s m a ll, i t w ould cause a s m a ll p e r tu r b a t io n

in even-even N=Z n u c le i (w h ich have c lo se d s p in - is o s p in20s h e l ls ) . F o r Ne , F ig u re 14 shows a gap o f 8 MeV. N u c le i

such as S32 and A r3® have c a lc u la te d gaps o f le s s th a n 5 MeV,

w h ich i s o f th e o rd e r o f th e s p in - o r b i t s p l i t t i n g . In th e

absence o f s p in - o r b i t s p l i t t i n g , th e wave fu n c t io n s o f th e28

2 i - 1 d s h e l l n u c le i w ou ld be sym m etric w ith re s p e c t to S i

The s p in - o r b i t s p l i t t i n g , how ever, in tro d u c e s an asymmetry

between p ro p e r t ie s o f th e n u c le i b e lo n g in g to th e f i r s t and•la *ta

second h a lv e s o f th e s h e l l ( c f . s e c t io n I V . 6 ) . F o r n e g l i -32g ib le s p in - o r b i t s p l i t t i n g , th e e l l i p s o id a l s o lu t io n f o r S

^ We speak here o f f i l l i n g th e lo w e s t a v a i la b le o r b i t a l in a schem atic way o n ly . As p re v io u s ly n o te d , th e a d d it io n o f a s in g le n u c le o n to an even-even n u c leus a l t e r s th e deform ed o r b i t a l s o lu t io n s . I t is n o t expected how ever, th a t t h is w ould change th e n a tu re o f th e d e fo rm a tio n .

++ A s p in - o r b i t te rm is in c lu d e d in b o th th e n u c le a r H a m il­to n ia n ( IV -1 ) and th e HF H a m ilto n ia n ( IV -8 ) by th e use o f e x p e r im e n ta l s in g le - p a r t ic le e n e rg ie s .

1 0 1

Page 151: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

20 24F ig u re 17. The spectrum o f HF o r b i t s o f Ne and Mg inth e case o f v a n is h in g s p in - o r b i t in t e r a c t io n . The o r b i t sa re la b e le d by t h e i r wave fu n c t io n in c o n f ig u ra t io n spaceand th e o r ie n ta t io n + and + o f th e s p in . N eu trons and p roto n s have s im i la r o r b i t s . O ccupied o r b i t s a re marked by ad o t . The n o ta t io n means £=2 ,m = l. The o r b i t s o f th ee l l i p s o id a l s o lu t io n a re la b e le d by th e s ta te ( n ,n , n )x y zto w h ich th e y a p p ro x im a te c lo s e ly .

Page 152: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

DEFORMED ORBIT COMPOSITIONS (Vso=0)

‘M W0.58d0+0.8l s0

-0.8ld0+0.58s0

N e 2 0 ( A X IA L )

E h f = - 3 4 . 2 9

A \ ’ \ ( 2 0 0 ) 4 t W r

W W f f i < " ° > W0.63do+0.77s„ (020) 4jA|r

t l 0 l ) i 4 f j r

- f t - —

^ t d| d- ' T H "

10111

(0 0 2 )-0.77 d0+ 0.63s0

M g 2 4 (A X IA L ) M g 2 4 (E L L IP S O ID A L )

E ^ p 2 —6 5 .9 6 E ^ p = - 7 3 . 6 3

Page 153: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1 02

i s a p p ro x im a te ly 15 MeV be low an a x ia l l y sym m etric s o lu t io n .

W ith in c re a s in g s p in - o r b i t s t r e n g th , th e HF e n e rg ie s o f th e

e l l i p s o id a l and a x ia l l y sym m etric s o lu t io n s approach each

o th e r , and f i n a l l y merge w ith th a t o f th e s p h e r ic a l e q u i l ib r iu m

shape. Recent e x p e r im e n ta l r e s u l t s 64 in d ic a te th a t S32 is

a lm o s t s p h e r ic a l . I t i s th e re fo re expected th a t th e re shou ld

be n o n -n e g l ig ib le c o n f ig u ra t io n m ix in g , w h ich is n o t ta ke n

in t o accoun t by th e HF wave fu n c t io n s . These w ould ten d to

d e s tro y th e s t a b i l i t y o f th e HF deform ed s ta te a g a in s t B and

Y v ib r a t io n s ( c f . s e c t io n s IV .6 e and I V . 7 ) .

5 . P a r t ic le - H o le A dm ix tu res to H a rtre e -F o c k

a . P re lim in a ry D is c u s s io n

I m p l i c i t i n H a rtre e -F o c k th e o ry is th e assum ption th a t

o n ly th e lo w e s t energy s in g le - p a r t ic le o r b i t s a re o ccu p ie d .

From e q u a tio n ( IV -2 6 ) i t i s im m e d ia te ly seen th a t i f th e

e f f e c t iv e n u c le o n -n u c le o n in t e r a c t io n c o n ta in s an exchange

te rm , h w i l l n o t be a lo c a l o p e ra to r . A p h y s ic a l ly s i g n i f i ­

c a n t consequence o f t h is n o n - lo c a l i t y i s th e p e rs is te n c e o f

an energy gap between o ccup ied and n o n -o ccu p ie d le v e ls . I f

t h is gap is s m a ll, a p a r t ic le - h o le expans ion around th e HF

i n t r i n s i c s ta te may indeed p ro v id e a su cce ss ive a p p ro x im a tio n

to lo w - ly in g n u c le a r s ta te s . F o r v e ry l i g h t n u c le i , such asO 1 p

Be and C , th e energy gap i s o f th e o rd e r 16-18 MeV, and

th u s th e assum ption o f a sharp Ferm i s u r fa c e i s v a l id . On

th e o th e r hand, f o r n u c le i in th e 26 - I d . s h e l l , th e energy

Page 154: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

103

gap is s ig n i f i c a n t l y s m a lle r (^5 -8 MeV), th e la r g e r gaps

a p p e a rin g in th e b e g in n in g o f th e s h e l l . The e f f e c t o f th e

decrease in gap s iz e i s e v id e n t from F ig u re 15. The Ne20

s o lu t io n , w h ich e x h ib i t s a la rg e gap (^8 MeV) in com parison

to th e o th e r n u c le i s tu d ie d , compares f a i r l y w e l l w ith th ep o p/r

e x p e r im e n ta l sp e c tru m ; S i and A r , how ever, w ith gaps

v5 MeV, compare p o o r ly w ith e xp e rim e n t.

A s s o c ia te d w ith th e decrease in s iz e o f th e energy gap

is an in c re a s e in th e p r o b a b i l i t y th a t p a r t ic le s in th e HF

s ta te w i l l s c a t te r ac ross th e gap to unoccup ied le v e ls . The

r e s u l t i s th e in t r o d u c t io n o f a degree o f d if fu s e n e s s to the

p re v io u s ly sharp Ferm i s u r fa c e , i . e . , th e upper-m ost "o c c u p ie d "

le v e ls in th e Ferm i sea may have le s s th a n u n i t p r o b a b i l i t y

o f b e in g o ccu p ie d , w h ile th e "u n o ccu p ie d " le v e ls may have

f i n i t e p r o b a b i l i t y o f b e in g o ccu p ie d .

I f i t i s s t i l l d e s ira b le to speak o f an i n t r i n s i c n u c le a r

wave fu n c t io n , th e n , based on th e above d is c u s s io n , i t sho u ld

be a m ix tu re o f th e H a rtre e -F o c k d e te rm in a n ta l s o lu t io n

and n - p a r t ic le /n - h o le d e te rm in a n ts . The p a r t ic le - h o le d e te r ­

m inan ts a re d e fin e d as h a v in g n "o c c u p ie d " s in g le - p a r t ic le

s ta te s empty (h o le s ) and n "u n o ccu p ie d " s ta te s f i l l e d (p a r ­

t i c l e s ) . The number n o f p a r t ic le s o r h o le s in a s ta te

|np-nh> th a t can s ig n i f i c a n t l y m ix w ith ¥^F shou ld be s m ^ ll

because these s ta te s w i l l have an u n p e rtu rb e d energy o f fh e

o rd e r nS above the HF e n e rg y , where <5 i s th e s iz e o f the

energy gap between o ccu p ie d and unoccup ied o r b i t s .

The one-body H a rtre e -F o c k s e l f - c o n s is te n t p o t e n t ia l i s

de te rm ine d such th a t tw o-body r e s id u a l in te r a c t io n s canncft

Page 155: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

cause lp - lh e x c i ta t io n s . I t has been argued th a t " th e HF

p o te n t ia l b e in g a one-body p o te n t ia l sh ou ld i t s e l f be a b le

to cause l p - l h typ e e x c i t a t i o n s ; . . . " th e H a m ilto n ia n i s thus

s ta b le a g a in s t 1 - p a r t i c le / l - h o le e x c i t a t io n s , and th e re fo re

th e lo w e s t-o rd e r c o r re c t io n to is th ro u g h a d m ix tu re o f

2p-2h typ e d e te rm in a n ts .56 W h ile i t i s t ru e th a t i s

s ta b le a g a in s t l p - l h e x c i t a t io n s , i t i s n o t th e t o t a l ad­

m ix tu re s w h ich a re im p o r ta n t , b u t r a th e r a d m ix tu re s to

s p e c i f ic t o t a l a n g u la r momentum components o f th e HF s ta te .

The sum o f these a d m ix tu re components v a n is h e s , b u t s in c e th e

t o t a l a n g u la r momentum c h a ra c te r iz e s th e e ig e n s ta te s o f th e

system , i t i s th e in d iv id u a l term s w h ich a re s ig n i f i c a n t .

Thus, o n e -p a r t ic le /o n e -h o le e x c i ta t io n s sh o u ld y ie ld th e

lo w e s t-o rd e r c o r re c t io n s to th e a n g u la r momentum components

P^ H F of> th e ^ s t a t e *

b . I s o to p ic S p in C o n s id e ra tio n s

P a r t ic le - h o le e x c ita t io n s o f th e HF s ta te r e a d i ly le n d

them se lves to th e p o ly n o m ia l p r o je c t io n te ch n iq u e s deve loped

in C hap te r I I i f th e is o s p in c o m p o s itio n o f these s ta te s is

s im p le enough. The one- and tw o - p a r t ic le - h o le c o n f ig u ra t io n s

co n s id e re d range in is o s p in from T = |T _ | to T= |T 1+2. Inz zth a t w h ich fo l lo w s , (-c) w i l l denote m u l t i - p a r t i c le s ta te s o f

th e v a r io u s typ e s d e s c rib e d be lo w . (1 ) s ig n i f ie s th e HF s ta te .

There a re two b a s ic typ e s (assum ing N=Z) o f 1 - p a r t i c le /

o n e -h o le e x c i ta i to n s to be c o n s id e re d :

(2 ) one e x c ite d n e u tro n , le a v in g a n e u tro n h o le In th e

104

Page 156: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

105

(3 ) one e x c ite d p ro to n , le a v in g a p ro to n h o le in th e HF

s ta te (F ig u re 1 8 b ). These s ta te s a re n o t a n n ih i la te d by the

is o s p in r a is in g o p e ra to r T+ . They a re , how ever, a n n ih i la te d

by T 2 , in d ic a t in g th a t th e y may c o n ta in b o th T=0 and T=1

is o s p in com ponents. These s ta te s may be combined in a p a r ­

t i c u l a r l y s im p le m anner, to produce pu re is o s p in s ta te s .

D e no tin g by ( 2 ) ' and ( 3 ) ' s ta te s o f th e above typ e s w ith the

same p a r t i c le and h o le s ta te s occup ied ( th e is o s p in p r o je c ­

t io n s a re exchanged), th e two n o rm a liz e d co m b in a tio n s a re

/ - | [ ( 2 ) , + ( 3 ) 1] and/ | [ ( 2 ) ' - ( 3 ) ' ] , w ith T=0 and T = l, re sp e c ­

t i v e l y . We n o te th a t th e fo rm e r , w h ich w ould u s u a lly be

c a lle d sym m etric because o f th e p lu s s ig n , i s a c tu a l ly a n t i ­

sym m etric in is o s p in space.

Fou r typ e s o f tw o - p a r t ic le / tw o - h o le s ta te s a re co n s id e re d

f o r even-even N=Z n u c le i :

(4 ) an e x c ite d p ro to n p a i r 1 (F ig u re 1 8 c ),

(5 ) an e x c ite d n e u tro n p a i r (F ig u re l8 d ) ,

(6 ) an e x c ite d n e u tro n -p ro to n p a i r w ith p o s i t iv e n e u tro n

z - p r o je c t io n (F ig u re l8 e ) ,

(7 ) an e x c ite d n e u tro n -p ro to n p a i r w ith n e g a tiv e n e u tro n

z - p r o je c t io n (F ig u re l 8 f ) . O the r n o n -p a ir tw o - p a r t ic le / tw o -

h o le c o n f ig u ra t io n s are n o t c o n s id e re d u s in g these methods

because t h e i r is o s p in co m p o s itin n s a re to o c o m p lic a te d . F o r

these i t w ou ld be necessary to in tro d u c e th e is o s p in r a is in g

t W ith a x ia l symmetry b e in g assumed in these c a lc u la t io n s , a p a i r i s d e f in e d as those degenera te s in g le - p a r t ic le HF e ig e n ­fu n c t io n s w ith o p p o s ite z - p r o je c t io n s .

HF state (Figure 18a),

Page 157: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F ig u re 18. 1 - and 2- p a r t ic le - h o le c o n f ig u ra t io n s . N eutronsa re shown to th e l e f t and p ro to n s to th e r i g h t . P a r t ic le s a re denoted by " x " and h o le s by " o " . (a ) and (b ) a re 1 -p a r -t i c l e / l - h o l e typ e e x c i t a t io n s , w h ile (c ) th ro u g h ( f ) a re 2 - p a r t ic le /2 - h o le typ e e x c i ta t io n s .

Page 158: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

I - AND 2 - P A R T IC L E H O LE C O N F IG U R A T IO N S

X XX o X X X X X o

n p n p

(a) (b)

X X X X X X X X

X X o o o o X X O X X o X o o x

n p n p n p n p

(c) (d) (e ) ( f )

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106

o p e ra to r d iscu sse d in s e c t io n I I . 4.

The HF s ta te o f even-even N=Z n u c le i c o n s is ts o f p a ire d

s in g le - p a r t ic le s ta te s w h ich are t im e -re v e rs e d o f each o th e r

and degenera te in e n e rg y . The HF s ta te is th e r e fo r e , by

d e s ig n , in v a r ia n t under tim e re v e rs a l ( c f s e c t io n I V . 3 ) .

T h is in v a r ia n c e p ro p e r ty sho u ld be re ta in e d by th e c o r re c te d

i n t r i n s i c s ta te c o n s is t in g o f th e o r ig in a l HF s ta te and p a r ­

t i c le - h o le a d m ix tu re s . T h e re fo re , those 2 - p a r t ic le /2 - h o le

s ta te s w h ich m ix most w ith th e o r ig in a l HF s ta te w i l l be

those w h ich have b o th t im e -re v e rs e d h o le s and t im e -re v e rs e d

p a r t ic le s in p a i r s ta te s ( ty p e s (4 ) and ( 5 ) , a b o ve ). The

same re a s o n in g a p p lie d to is o s p in in v a r ia n c e p re d ic ts th a t

those s ta te s w h ich m ix most w ith th e HF s ta te w i l l have h o le s

o r p a r t ic le s w h ich a re e i t h e r b o th p ro to n s o r b o th n e u tro n s .

S ta te s o f th e typ e s (6 ) and (7 ) a re in c lu d e d because these

have la rg e o v e r la p w ith th e 1 - p a r t i c le / l - h o le s ta te s . They

a re a ls o re q u ire d f o r th e s im p le c o n s tru c t io n o f T=0 s ta te s .

We have , th e r e fo r e , in c lu d e d those 2 - p a r t ic le /2 - h o le s ta te s

w h ich have maximum o v e r la p w ith th e HF s ta te and i t s 1 -p a r ­

t i c l e / l - h o l e e x c i ta t io n s . The use o f an in co m p le te s e t o f

2 - p a r t ic le /2 - h o le s ta te s sh o u ld n o t , th e r e fo r e , be to o d e t r i ­

m en ta l to th e r e s u l t s . The above ch o ice s a re s u f f i c ie n t to

c o n s tru c t s im p le is o s p in s ta te s , as shown be low .

As in th e case o f th e 1 - p a r t i c le / l - h o le c o n f ig u ra t io n s ,

pure is o s p in s ta te s may be o b ta in e d from th e above fo u r type s

(w ith p rim es a g a in s ig n i f y in g s ta te s w ith id e n t ic a l p a r t i c l e -

h o le s t r u c tu r e and exchanged is o s p in p r o je c t io n s ) by fo rm in g

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107

the following simple combinations:

T=0 i [ {(4)■ + (5 ) ' } - 1(6) ' + ( 7 ) ' ) ]

T=1 k C t*1) ' “ ( 5 ) ’ ]

| C ( 6 ) ' - ( 7 ) ' ]

T=2 | [ { (4 )> + ( 5 ) ’ } + { ( 6 ) ' + ( 7 ) ' ! ]

To f a c i l i t a t e th e w r i t in g o f n o rm a lize d i n t r i n s i c s ta te s o f

good is o s p in , th e fo l lo w in g n o rm a liz a t io n s and phases a re

in tro d u c e d :

U s ing th e se s im p le co m b ina tio n s ( IV -2 8 ) as i n t r i n s i c

s ta te s fro m w h ich p r o je c t io n i s to be accom p lished c o m p le te ly

o b v ia te s th e need to s im u lta n e o u s ly p r o je c t is o s p in and angu­

l a r momentum. T h is w ou ld re p re s e n t a fo rm id a b le p rob lem s in ce

an N -n e u tro n Z -p ro to n p rob lem w ould in v o lv e an N+Z n e u tro n

re p re s e n ta t io n and th e employment o f th e is o s p in r a is in g o r

lo w e r in g o p e ra to r , in a manner ana lagous to th e use o f th e

a n g u la r momentum r a is in g o p e ra to r d iscu sse d in C hap te r I I .

I n f a c t , w ith th e above c o m b in a tio n s , is o s p in need h a rd ly be

a c o n s id e ra t io n when p e rfo rm in g th e c a lc u la t io n s .

( IV -2 7 )

N o rm a lized s ta te s may now be w r i t t e n

( IV -2 8 )

Page 161: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1 08

^ab^ = N1 | v ( a ) ir (b ) + p1v (b ^Ti( a ) > . ( IV -2 9 )

These a re th e n combined to th e s ta te s ( IV -2 8 ) . (We no te

th a t th e se s ta te s ( IV -2 9 ) w i l l have sharp is o s p in o n ly f o r

th e HP s ta te and i t s 1 - p a r t i c le / l - h o le e x c i t a t io n s . )

c . The Use o f R eference N u c le i and Hole S ta te s

The use o f re fe re n c e c lo s e d -s h e l l n u c le i i s o f g re a t

a s s is ta n c e in p e rfo rm in g s h e l l model c a lc u la t io n s , b u t as

a lre a d y m e n tion e d , th e assum ption o f an in e r t co re m igh t

p re c lu d e a f u l l u n d e rs ta n d in g o f th e e le c t r i c and m agne tic

p ro p e r t ie s o f th e n u c le u s . S ince th e main in t e r e s t In

these c a lc u la t io n s i s in th e energy s p e c tra and wave fu n c ­

t io n s , w i l l be used as th e re fe re n c e n u c leu s f o r th e

lo w e r h a l f o f th e 2 6 - 1 d s h e l l (Ne20 , Mg2*1 and S i2® ), and

Ca**° f o r th e upper h a l f o f th e s h e l l (S32 and A r3® ). The

f i l l i n g o f o r b i t s in th e 2 6 - 1 d s h e l l n u c le i may be re fe re n c e d

to th e f i l l i n g in 0 1® o r Ca**° as fo l lo w s :

A M N1 = 1 + I + 1

A=1 l e r e f y = lv = l

The M " p a r t i c le o r b i t s " y a re f i l l e d in th e n u c le u s under

c o n s id e ra t io n , b u t empty in th e re fe re n c e n u c le u s ; th e N

"h o le o r b i t s " v a re empty in th e n uc leu s b e in g s tu d ie d ,

b u t f i l l e d in th e re fe re n c e n u c le u s . Thus, f o r n u c le i below 28S i th e f i r s t summation on I i s o ve r th e 16 and 1p s h e l ls .

Projections are actually performed using states of the

form

Page 162: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

109

The p a r t ic le o r b i t s y may b e lo n g to th e 2 6 - 1 d s h e l l o r

h ig h e r s h e l ls , and th e h o le o r b i t s v to th e 16 and 1p s h e l ls? Rf o r n u c le i above S i , th e o r b i t s I may b e lo n g to th e 74,

1p and 2 6 - 1 d s h e l ls , th e p a r t ic le o r b i t s y to the 2 p - 1 £

s h e l l o r h ig h e r s h e l ls , and th e h o le o r b i t s v to th e 2 6 - 1 d

s h e l l o r lo w e r s h e l ls .

The HF H a m ilto n ia n ( IV -8 ) now becomes

<4>i |7i|<j)j> = <<J»i 111 <f>j> + ^ I f <<l,i Xj l |v |< j)jX )l>

M N+MI < * i xv M - J < q x v iv| V v > .

The f i r s t l in e above is ju s t th e HF H a m ilto n ia n o f th e r e fe r

ence c lo s e d -s h e l l n u c le u s , w h ich i s d ia g o n a l and has s p h e r i­

c a l s o lu t io n :

M N- e+ i«± j + I ^ i X y |V |4 'JXU> ~v I< * iX v (VI * jX v>

where o n ly p a r t i c le and h o le o r b i t s appear and the are

s in g le - p a r t ic le o r h o le e n e rg ie s i n th e 0 "^ o r C a ^ f i e l d ,

r e s p e c t iv e ly .lin

The use o f Ca f o r th e upper s h e l l n u c le i im p lie s th a t

th e HF s ta te s o f S32 and A r3^ must now be e n v is io n e d as con­

s is t in g o f h o le s r a th e r th a n p a r t ic le s . That w h ich was p re ­

v io u s ly c o n s id e re d n - p a r t ic le /n - h o le e x c ita t io n s o f th e HF

s ta te must how be co n s id e re d n - h o le /n - p a r t ic le e x c i t a t io n s .

T e c h n ic a l ly , t h is poses o n ly a s m a ll p rob lem w hich is e a s i ly

d e a lt w i th . I t w i l l be shown below th a t an a lm ost c lo se d

s h e l l I s e q u iv a le n t , in a sense, to an a lm os t empty s h e l l .

Page 163: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The t o t a l number m o f p a r t ic le s (n e u tro n s o r p ro to n s )

w h ich can be p la ce d in a g iv e n s h e l l is

m = I (2 /+ 1 )S

where th e summation extends o ve r a l l va lu e s o f p a r t ic le

a n g u la r momentum a llo w e d in th e p a r t ic u la r s h e l l under s tu d y .

Thus, f o r th e 26 - 1 d s h e l l , m=2+4+6=12. F o r an n - p a r t ic le

s ta te , w ith n>m/2, i t i s more co n ve n ie n t to s p e c ify a s ta te

o f th e system by th e s e t o f m-n uncocup ied o r h o le s ta te s .

A o n e -to -o n e correspondence may be e s ta b lis h e d between each

n - p a r t ic le s ta te and a co n ju g a te n -h o le s ta te . The number

o f these c o n ju g a te h o le s ta te s i s , o f n e c e s s ity , e q u a l to th e

number o f p a r t ic le s ta te s .

We c o n s id e r now th e tw o-body p a r t V o f th e H a m ilto n ia n .

D en o ting th e s e t o f a l l quantum numbers necessary to s p e c ify

a g iv e n p a r t i c l e s ta te by y , each row and column in th e m a tr ix

I v i k may be c h a ra c te r iz e d by a s e t o f n numbers y^> y2> • • >Vln *i r i ' ' '

S ince is a tw o - p a r t ic le o p e ra to r , < 1 ^ 2 • • • V * v i k l pi p2 - - * V

d i f f e r s fro m ze ro o n ly i f th e s e t y^ d i f f e r s from th e s e t y |

by a t most two members. F o r th e d ia g o n a l e lem ents o f th e

n - p a r t ic le c o n f ig u ra t io n

<yl y 2* ’ ^ Vi k l ul y 2 ’-“ y n> = I < ^ ’ |v 1 2 | y y ’ > . ( iv - 3 0 )i , k = l y > y *

y , y ' = y 1y 2 * • *Un S im i la r ly , f o r th e n o n -d ia g o n a l e lem ents

Page 164: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

where i t is assumed th a t th e s e t y.£ d i f f e r s from th e s e t y^

in a t most th e f i r s t two e le m e n ts . S ince th e m u l t i - p a r t i c le

s ta te s c o n s id e re d a re S la te r d e te rm in a n ts , th e y can a lways

be re o rd e re d so th e d i f f e r i n g s ta te s appear f i r s t .

L a b e lin g th e s ta te s o f th e n -h o le c o n f ig u ra t io n by th e

unoccup ied v a lu e s o f y r a th e r th a n th e o ccup ied va lu e s

<y - 11j J 1 . . . u * 1 | i f V . J u - R i - L - . y - L = I< v y ' |V |p y ’ > ( IV -3 2 )l , k = t t + l

y ,y» = * “ y n*

Here th e summation extends o ve r a l l va lu e s o f y d i f f e r e n t

from y ^ , y 2 , • • , y n » i . e . , o ve r th e m-n occu p ied y - s ta te s . Now,

Ill

I <yy ' |V|yy'> = \ \ <yy•|V|yy * >y>U * d . .

y , y - ^ y 1 . . . y n

= \ { I < y y ’ |v |y y '> - I I < y , y ' | V | y , y ’ >2 yy* i = l y 1

- I I< y y jL|v |y y 1>} + | I < yy1 |V |y y '> . ( IV -3 3 )1 -1 y 2y y '= y 1 - * y n

That i s , th e f i r s t summation in b ra c k e ts has no r e s t r i c t io n s

on e i t h e r y o r y ' , th e second summation has no r e s t r i c t i o n on\

y ' , and th e t h i r d no r e s t r i c t i o n on y . The e x p re s s io n above

in b ra c k e ts , denoted by EQ, is independen t o f th e s p e c i f ic

va lu e s o f y ^ y 2 ’ ’ *y n* c o n t r i b u t i ° ns to th e second and t h i r d

te rm s a re each independen t o f y ^ . Comparing e q u a tio n s ( IV -3 1 )

and ( IV -3 3 ) , f o r d ia g o n a l e lem ents

Page 165: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1 12

> = E + oi,k = w + l

<V lV 2 - - - V n l | Z Vi , k = l

A s im i la r c a lc u la t io n shows th a t f o r th e n o n d ia g o n a l e lem ents

C o m p le te ly ana lagous r e s u l ts can be shown to be t ru e f o r the

one-body p a r t o f th e H a m ilto n ia n . T h e re fo re , th e e n t i r e

H a m ilto n ia n m a tr ix in a h o le c o n f ig u ra to n i s e qua l to a con­

s ta n t Eq p lu s th e tra n sp o se d m a tr ix o f th e co n ju g a te p a r t ic le

c o n f ig u r a t io n . The s p e c tra f o r th e two c o n f ig u ra t io n s a re

th e same, b u t s h i f t e d by th e amount Eq . T h is p roves p a r t ic u ­

l a r l y u s e fu l in t r e a t in g S32 and A r3^ as 8 - and 4 -h o le40system s, r e s p e c t iv e ly , w ith Ca as re fe re n c e n u c le u s , r a th e r

th a n as 16- and 2 0 - p a r t ic le system s, r e s p e c t iv e ly , w ith

as re fe re n c e n u c le u s .

d . P ro je c t io n E q u a tion s and Wave F u n c tio n A n a ly s is

C a lc u la t io n s have been c a r r ie d o u t u s in g i n t r i n s i c s ta te s

o f th e fo rm ( IV -2 9 ) . Each s ta te is a s u p e rp o s it io n o f

s ta te s w ith v a r io u s a n g u la r momentum components ( c f . s e c t io n

i , k = n + l

i , k = l

II.2):

( IV -3 6 )

Page 166: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

The p o ly n o m ia l p r o je c t io n te ch n iq u e s o f s e c t io n I I . 4 c a r ry

o ve r q u ite s im p ly . The ana logue o f e q u a tio n (1 1 -2 4 ) may be

deve loped as

<J+W*a b >l J +P* c d )> , 0 , y ) a jba j d< J ,y , (a b ) | J , y , (cd )> ( IV -3 7 )

= (2 -6 1 J )N1NJ <J+»1Cv( a ) ir ( b ) +p1v ( b ) ir ( a ) ] | J +*lv ( c ) i r ( d ) >

= (2 -6 )N N J W 2 I I B (J ,0 ,X )B (J 2 ,0 ,y -X ) 1 J =0 l AJ j 1=x J 2=y-X 1

[ Ma c 'Mb d 2+ P iMSo‘ Mad2;l ( IV ' 38)

S im i la r ly , ana lagous to e q u a tio n (1 1 -2 7 ) ,

<J+P*a b ) l H l J +P,,,c d )> = I B (J»0»Vi)a5ba5d< J ,y , ( a b ) |H |J ,y , ( c d ) >J ( IV -3 9 )

= (2 -6 , )N N I { M 2[ I I B (J , ,0 ,X )B (J 2 ,0 ,y -X )1 Jx=0 W J j J 2

i K l ' Hb f 2 + Ha e X f 2) +pi K e lH d f 2+HSe1Md f 2) }

+ I Mb s 2 + pi Hnp^rs , e f Mc r X Md s 2 ) ]r s

+ M I [ x !!m | I / B ( J 1>0 ,X ) /B ( J 1,mr ,X-mr ) /B ( J 2 ,0 ,y -X ) * rs ' -

113

• 'B (J2 ,-m r ,u-X+mr ) [H ^ p ( r s ,e f ) M ^ > N ^ 2

+ P iHn p ( l ’s - e f)N c r 1 Md f 2 ]>

( IV -4 0 )

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114

Once a g a in , the m e tr ic a p p e a rin g in e q u a tio n ( IV -3 7 )

is o b ta in e d by su cce ss ive e l im in a t io n o f a n g u la r momentum

components b e g in n in g w ith Jmax, and th e o r th o n o rm a liz in g

m a tr ix (1 1 -1 2 ) is o b ta in e d v ia th e Schm idt o r th o n o rm a liz a t io n

p roce du re ( v . s e c t io n I I . 3 ) . The H a m ilto n ia n m a tr ix a p p e a rin g

in e q u a tio n ( IV -3 9 ) is th e n c a lc u la te d , and th e m a tr ix (1 1 -1 2 )

is a p p lie d t o . y ie ld th e H a m ilto n ia n m a tr ix in an o rth o n o rm a l

subspace f o r each v a lu e o f a n g u la r momentum and is o s p in .

These a re th e n d ia g o n a liz e d , r e s u l t in g in energy s p e c tra and

wave fu n c t io n s f o r th e e n t i r e system .

Wave fu n c t io n s o f th e H a m ilto n ia n may be expanded

as l in e a r co m b in a tio n s o f th e J -T components o f th e i n t r i n s i c

n e u tro n -p ro to n s ta te s :

* j £ > - I (PJT'l>np>> » ( I V - i l l )k

i kwhere a .j^ a re a m p litu d e c o e f f ic ie n t s . These wave fu n c t io n s

a re o b ta in e d v ia th e d ia g o n a liz a t io n o f th e H a m ilto n ia n

m a tr ix in a n o th e r o r th o n o rm a l b a s is ^

'1JT ) ° I < I V - 1 , 2 )m

w h ic h , in t u r n , is d e te rm in e d from th e i n t r i n s i c b a s is by the

Schm idt o r th o n o rm a liz a t io n p ro ce d u re :

♦ j " ’ = I BJ ? (pJT '*'nD>) • ( I V - Ws

The a m p litu d e s al k may th us be expanded in term s o f th e o r th o ­

n o rm a liz a t io n and e ig e n v e c to r m a tr ic e s. ik _ j Aim Dmk

mi k _ r Aim nmkJT “ L J T J T ( IV -4 4 )

Page 168: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

JT (\c)We n o te , how ever, th a t th e e x p l i c i t fo rm P d> is n o tnpo b ta in e d by t h is p r o je c t io n p ro ce ss .

6 . R e s u lts o f C a lc u la t io n s

a . G enera l Remarks

The m e tr ic o f th e J = 0 subspace o f T=0 s ta te s used in 20th e Ne p a r t ic le - h o le m ix in g c a lc u la t io n is p re se n te d in

T ab le X. The s ta te s la b e le d l p - l h (k ) and 2p-2h (k ) a re

th e n o rm a liz e d co m b in a tio n s o f p a r t ic le - h o le e x c i ta t io n s

d iscu sse d in s e c t io n IV .5 b , w ith (k ) s ig n i f y in g th e a n g u la r

momentum p r o je c t io n on to th e a x is o f symmetry o f th e deform ed

p a r t i c le s ta te ( v . T ab le IX ) to w h ich th e p a r t ic le ( p a i r ) is

e x c ite d . O f p a r t ic u la r im po rtan ce I s th e e x is te n c e o f non­

ze ro 1 - p a r t i c le / l - h o le m e tr ic com ponents, and th e la c k o f

o r th o g o n a l i ty o f these to th e HF component. T y p ic a l o v e r­

la p s o f th e HF and p a r t ic le - h o le J=0 , T=0 components a re o f

th e o rd e r 1 /1 0 , based on n o rm a liz e d a m p litu d e s . The o v e rla p s

o f th e 1 - and 2 - p a r t ic le - h o le components o f t h is m e tr ic a re

o f th e same o rd e r o f m agn itude . We n o te th a t th e 2p-2h s ta te s

have a r a th e r la rg e J=0 com ponent, and th a t th e y th u s re p re s e n t

an in t r o d u c t io n o f p a i r in g c o r r e la t io n s .

The s p e c tra o b ta in e d from th e p a r t ic le - h o le m ix in g c a l­

c u la t io n s f o r N e ^ , M g ^ , S i ^ , S ^ , and A r^ b a re p re se n te d

in F ig u re s 19-23 f o r p r o je c t io n s fro m : (a ) th e HF s ta te ,

(b ) th e HF s ta te and 1 - p a r t i c le / l - h o le e x c i t a t io n s , (c ) th e

HF s ta te and 2 - p a r t ic le /2 - h o le e x c i t a t io n s , and (d ) th e HF

s ta te and 1 - and 2 - p a r t ic le - h o le e x c i t a t io n s . P a rts (e ) show

115

Page 169: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

TABLE X

M e tr ic o f J=0, T=0 Subspace o f S ta te s Used in Neon 20 M ix in g C a lc u la t io n s

HFlp - l h( 1 /2 '

HF .1088 .0196lp - l h ( 1 / 2 ' ) .0196 .1451lp - l h ( 1 /2 " ) -.0 3 3 5 -.0 1 7 02p-2h ( 1 / 2 ' ) .0466 .06602p-2h ( 1 /2 " ) .0439 .0325

lp - l h 2p-2h 2p-2h( 1 /2 " ) ( 1 /2 1) ( 1 /2 " )

- .0 3 3 5 .0466 .0439-.0 1 7 0 . 0660 .0325

.1172 -.0 2 8 3 -.0 1 7 4

-.0 2 8 3 .7332 .0773-.0 1 7 4 .0773 .6462

Page 170: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

116

th e lo w -e n e rg y p o s i t iv e p a r i t y e x p e rim e n ta l s p e c tra . The

HF deform ed p a r t ic le bases used a re those l i s t e d in T ab le IX .

A p re s e n ta t io n o f e ig e n fu n c t io n s o f th e H a m ilto n ia n ,

expanded on th e n a tu r a l bases o f a n g u la r m om entum -isospin

subspaces o f th e H a rtre e -F o c k , 1 - p a r t i c le / l - h o le , and 2 -p a r -

t i c le / 2 - h o le s ta te s , ( e . g . , those o f th e J=0 , T=0 m e t i ic o f 20Ne d iscu sse d above) w ould be e x tre m e ly d i f f i c u l t to com­

prehend because o f th e la c k o f o r th o n o rm a lity w i t h in these

subspaces. In s te a d , th e e ig e n fu n c t io n s a re expanded on

o rth o n o rm a l bases o b ta in e d by a p p l ic a t io n o f th e Schm idt

p roce du re to th e subspace m e tr ic s . The Schm idt te ch n iq u e

i s e x tre m e ly u s e fu l in t h is a p p l ic a t io n s in c e th e f i r s t T=0

fu n c t io n in th e o rth n o rm a l b a s is may be chosen as th e no rm a l­

iz e d H a rtre e -F o c k component a lo n e ; th e f i r s t T=1 fu n c t io n a

n o rm a liz e d 1 - p a r t i c le / l - h o le component; th e f i r s t T=2 fu n c t io n

a n o rm a liz e d 2 - p a r t ic le /2 - h o le com ponent. S uccess ive o r th o ­

no rm a l fu n c t io n s a re o b ta in e d by ta k in g those p a r ts o f th e

a p p ro p r ia te p a r t ic le - h o le components o rth o n o rm a l to the

fu n c t io n s p re v io u s ly chosen in each case , e tc .

b . Neon 20

F ig u re 19 is a p re s e n ta t io n o f th e r e s u l ts o f th e m ix in g20c a lc u la t io n s pe rfo rm e d on Ne . The s p e c tra a re n o rm a liz e d

to ze ro ground s ta te e x c i t a t io n e n e rg y . The " T o ta l11 spectrum

(F ig u re 1 9 d ) , w h ich c o n ta in s b o th 1 - and 2 - p a r t ic le - h o le

c o n f ig u ra t io n s in a d d it io n to th e HF s ta te , l i e s 220 KeV

be low th e pu re HF spectrum (F ig u re 1 9 a ).

Page 171: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

117

As can be seen from F ig u re 16, H a rtre e -F o c k th e o ry suc­

c e s s fu l ly p r e d ic ts th e e x c i t a t io n e n e rg ie s o f th e ground K=020r o t a t io n a l band o f Ne . The e x p la n a t io n o f th e e x c ite d J=0

le v e l a t 6 .72 MeV e x c i t a t io n energy has been a tta c k e d by

v a r io u s a u th o rs , n o ta b ly by B a s s ic h is and K e lso n 55 by the

method o f tim e -d e p e n d e n t H a rtre e -F o c k th e o ry , and by B a r-T o u v61*

as a one-phonon ^ - v ib ra t io n ( c f . Appendix A - I I ) o f th e HF

ground s ta te . Both a u th o rs have o b ta in e d e n e rg ie s f o r t h is

s ta te in rough agreem ent w ith th e e x p e rim e n ta l v a lu e .

Based on these w o rks , s im p le p a r t ic le - h o le e x c i ta t io n s

o f th e HF s ta te appear to be a p a r t i c u la r l y a p p e a lin g way

to e x p la in th e appearance o f th e 6 .72 MeV s ta te . In l in e

w ith t h is b e l i e f , T e w a r i57 has been q u ite s u c c e s s fu l in h is

a p p l ic a t io n o f a Tamm-Dancoff a p p ro x im a tio n to th e HF s ta te .

H is r e s u l ts a re shown in F ig u re 1 9 f. In th e p re s e n t c a lc u ­

la t io n s , no such r e s t r i c t i o n has been a p p lie d . As can be

seen fro m F ig u re 19, th e 1 - p a r t i c le / l - h o le e x c i t a t io n to

th e deform ed k = i / 2 ' le v e l ( v . T ab le IX ) p r e d ic ts a r o t a t io n a l

band w i t h in th e v i c i n i t y o f th e e x p e r im e n ta lly observed band

a t 6 .72 MeV. Tab le X I shows th a t th e s ta te s o f t h is band have

some m ix tu re from th e h ig h e r p a r t ic le - h o le e x c i t a t io n to th e

k = l /2 " s ta te (v . Tab le IX ) . Because o f th e la rg e energy gap

(^8 MeV) between occup ied and unoccup ied o r b i t a ls in th e HF 20s ta te o f Ne (v . F ig u re 1 5 ), 2 - p a r t ic le /2 - h o le c o n f ig u ra t io n s

a re expected to be s ig n i f i c a n t l y h ig h e r in e x c i t a t io n energy

th a n th e 1 - p a r t i c le / l - h o le c o n f ig u r a t io n s , and th e r e fo r e , n o t

to m ix w ith t h is e x c ite d K=0 band. T h is is th e case , as shown

Page 172: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1 1 8

in F ig u re 19. Tab le X I shows th a t th e re a c tu a l ly Is a v e ry

s l i g h t m ix in g among these c o n f ig u ra t io n s .

The e x p e r im e n ta l J=0 le v e l a t 7 .2 MeV e x c ita io n energy

i s n o t accounted f o r by e i t h e r 1 - p a r t i c le / l - h o le o r 2 - p a r t i c le /

2 -h o le e x c i t a t io n s . T h is s ta te may be th e r e s u l t o f m u l t ip le -

p a r t ic le - h o le e x c i ta t io n s from th e 1p s h e l l . C o r ro b o ra tio n

i s g iv e n to t h is s u p p o s it io n by th e appearance o f a 4p-4h

J=0 s ta te a t a p p ro x im a te ly th e same e x c i t a t io n energy (6 .0 6

MeV) in Ol 6 ®3. I t i s , o f c o u rs e , p o s s ib le th a t such I p s h e l l

e x c i ta t io n s w ou ld m ix w ith th e p a r t ic le - h o le e x c i ta t io n s

c o n s id e re d h e re , th u s y ie ld in g b e t te r agreem ent between th e

c a lc u la te d e x c ite d band and th e e x p e r im e n ta l v a lu e s . A one-

to -o n e correspondence between th e t h e o r e t ic a l and e x p e rim e n ta l

band s t ru c tu r e s is co m p lic a te d by an appa re n t r o ta t io n a l

spectrum b u i l t on th e 7 .2 MeV J=0 s ta te .

Page 173: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F ig u re 19. C a lc u la te d and e x p e r im e n ta l s p e c tra o f Neon 20.The spectrum la b e le d (a)HF is th e energy le v e ls p ro je c te d fro m th e H a rtre e -F o c k s ta te . The spectrum la b e le d (b ) l p - l h in c lu d e s a d ia g o n a liz a t io n o f a l l 1 - p a r t i c le / l - h o le s ta te s c o n s id e re d w ith th e H a rtre e -F o c k s ta te ; th a t la b e le d (c )2p-2h in c lu d e s a d ia g o n a liz a t io n o f a l l 2 - p a r t ic le /2 - h o le s ta te s c o n s id e re d w ith th e H a rtre e -F o c k s ta te . The spectrum la b e le d (d ) T o ta l in c lu d e s an e xa c t d ia g o n a liz a t io n o f b o th l p - l h and 2p-2h e x c i ta t io n s c o n s id e re d w ith th e HF s ta te .The e x p e r im e n ta l p o s i t iv e p a r i t y spectrum is la b e le d (e )E x p t . I n d iv id u a l le v e ls a re la b e le d by a n g u la r momentum and s p in ( J ,T ) . The spectrum o b ta in e d by T e w a r i57 is la b e le d ( f ) .

Page 174: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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Page 175: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Tab le X I

Wave F u n c tio n C om pos ition o f L o w - ly in g Neon 20 S ta te s

J (T ) HF lp - lh( 1 /2 * )

l p - l h( 1 /2 " )

2p-2h( 1 / 2 ' )

2p-2h( 1 /2 " )

E x c itEnergy

0 (0 ) .9902 -.0 4 9 9 -1259 .0342 • 0065 0 .002 (0 ) .9939 -.0 4 3 9 .1010 .0023 .0047 1 .324 (0 ) .9754 -.1 7 7 4 .1274 .0256 .0287 3.750 (0 ) .0960 .9129 -.3 9 5 5 .0130 -.0 2 7 7 5.286 (0 ) .9899 -.1 3 7 4 .0012 .0013 .0348 7.802 (0 ) .0812 .9109 -.4 0 2 7 -.0 3 7 3 -.0 0 8 2 8.244 (0 ) .2170 .8330 -.5 0 3 8 -.0 7 1 0 .0159 10.338 (0 ) .9407 -.3 3 8 2 - - -.0 2 4 5 10.773 (1 ) - .9949 -.0 9 6 4 .0207 -.0 2 0 0 12.148 (2 ) - - - .8626 .5059 12.330 (1 ) - .9962 .0749 .0433 .0072 12.46

1 (1 ) - .9786 -.2 0 5 3 -.0 0 7 5 -.0 0 8 2 12.76

2 (1 ) - .9982 .0388 -.0 0 3 4 -.0 4 5 5 12.88

3 (0 ) - .9984 -.0 5 7 4 - - 12.990 (2 ) - - - .9871 .1600 13.451 (0 ) - - .0 6 8 6 .9888 -.1 3 2 7 -.0 0 0 3 13.50

5 (1 ) — ;9968 -.0 6 2 1 -.0 3 7 4 .0331 13.68

Page 176: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Mg a re p re se n te d in F ig u re 20 and T ab le X I I . The s p e c tra

a re n o rm a liz e d to ze ro ground s ta te e x c i t a t io n e n e rg y . The

" T o ta l" (F ig u re 20d) sp e c trum , c o n ta in in g b o th 1 - p a r t i c le /

l - h o la and 2 - p a r t ic le /2 - h o le c o n f ig u ra t io n s in a d d it io n to

th e HF s ta te , l i e s 230 KeV lo w e r in energy th a n th e pure HF

spectrum (F ig u re 2 0 a ).s A 25P a r ik h has made a n a ly s is o f th e wave fu n c t io n s o f Mg

24based on th e assum ption o f a n e u tro n in th e Mg HF f i e l d ,

f o r b o th t r i a x i a l and a x ia l l y sym m etric HF s o lu t io n s . The

a x ia l l y sym m etric s o lu t io n was found to g iv e b e t te r ag re e ­

ment w ith s p e c tro s c o p ic fa c to r s and d e c o u p lin g pa ram ete rsnji OC

o b ta in e d 67 fro m th e s t r ip p in g r e a c t io n Mg (d ,p )M g , th an

does th e t r i a x i a l s o lu t io n . T h is occu rs in s p i te o f the

f a c t th a t th e t r i a x i a l s o lu t io n is lo w e r in energy ( c f . F ig u re

15 and Tab le IX ) th a n th e a x ia l s o lu t io n . W ith t h is in m ind,

i t seems o n ly a p p ro p r ia te to p e rfo rm m ix in g c a lc u la t io n s based

on th e a x ia l l y sym m etric s o lu t io n .

The appearance o f a lo w - ly in g K=2 r o ta t io n a l band a t

4 .27 MeV e x c i t a t io n energy in th e e x p e r im e n ta l spectrum

(F ig u re 20e) cannot be e x p la in e d on th e b a s is o f th e p a r t i c l e -

h o le c o n f ig u ra t io n s co n s id e re d h e re . T h is is because these

were r e s t r ic t e d to c o n f ig u ra t io n s w h ich w ou ld m ix w ith th e

HF s ta te , i . e . , K=0 c o n f ig u ra t io n s . I t s h o u ld , how ever, be

n o te d th a t the se c o n f ig u ra t io n s w ith K=2 can be o b ta in e d from

an a x ia l tre a tm e n t in th e fo l lo w in g m anner. We can c o n s id e r

119

c. Magnesium 24

The results of particle-hole mixing calculations for24

Page 177: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

120

*2 “ ^ AaXba 6XVHF a x

where th e s e t {X } a re o ccup ied o r b i t s and (a ) a re unoccup ied

o r b i t s , a re a m p litu d e c o e f f ic ie n t s , and ka- k x=2. T h is

s ta te i s a l in e a r co m b in a tio n o f 1 - p a r t i c le / l - h o le e x c i t a t io n s ,

a lb e i t n o t o f . th o s e c o n s id e re d in t h is c a lc u la t io n . We must

be c a r e fu l , how ever, n o t to in c lu d e p a r t ic le - h o le c o n f ig u ra ­

t io n s w h ich may u l t im a te ly be d e s c rib e d as These

w i l l , o f c o u rs e , be o r th o g o n a l to th e HF s ta te , b u t w i l l r e ­

p re s e n t s p u r io u s s o lu t io n s s in c e a n g u la r momentum p r o je c t io n s

fro m th e two w i l l be id e n t ic a l . A n o th e r tre a tm e n t is th e

r o t a t io n a l d e s c r ip t io n o f fe re d by B ar-Touv and K e lso n 68, in

w h ich th e y c o n s id e re d a s in g le asym m etric d e te rm in a n ta l

i n t r i n s i c s ta te

' 4> = n bx |0> ,

X AK=0 K=2o u t o f w h ich th e y p r o je c t P ” <f> and P ~ <j>. They found th e

K=pva lu e 0 .94 f o r th e o v e r la p <<f>2 l p ” w h ich dem onstra tes

th e coa lescence o f th e v ib r a t io n a l and r o t a t io n a lv —p

(P <J>) d e s c r ip t io n s o f these s ta te s .

An in t e r e s t in g fe a tu re ( v . F ig u re 20d) w h ich a r is e s is

th e appearance o f a n o th e r K=0 r o ta t io n a l band a t 6 .50 MeV

e x c i t a t io n e n e rg y , w h ich agrees re m a rka b ly w ith th e p o s i t io n

o f a lo w - ly in g J=0 le v e l in th e e x p e rim e n ta l spectrum (6 .4 7

MeV). The e x p e r im e n ta l spectrum (F ig u re 20e) shows a J=2

le v e l a p p ro x im a te ly 300 KeV above th a t p re d ic te d by the

m ix in g c a lc u la t io n . A n a ly s is o f th e wave fu n c t io n s (v . Tab le

another intrinsic state of a vibrational nature:

Page 178: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

X I I ) o f t h is band shows th a t I t a r is e s from a m ix tu re o f

two k = l /2 1 - p a r t i c le / l - h o le c o n f ig u ra t io n s , and extends a l l

th e way to J=10 a t 9 .7 MeV e x c i ta t io n e n e rg y .

A no th e r r o ta t io n a l band, e x te n d in g in a n g u la r momentum

to J=12, appears a t 11.33 MeV e x c i ta t io n e ne rg y . U n lik e th e

lo w e r band, i t has an is o s p in assignm ent T=2. The band is

somewhat d is to r te d a t h ig h a n g u la r momentum va lu e s ( th e J=8

and J=10 le v e ls a re w i t h in 50 KeV o f each o th e r ) . T h is is

p ro b a b ly due to th e la c k o f c o n s id e ra t io n o f o th e r p a r t i c l e -

h o le (b o th 2 - and h ig h e r ) c o n f ig u ra t io n s w h ich w ould m ix

s ig n i f i c a n t l y a t th e e x c i t a t io n e n e rg ie s co n s id e re d h e re .

I t sh o u ld be remembered th a t a d d i t io n a l 2p-2h c o n f ig u ra t io n s

were n o t t re a te d because (+.) t h e i r is o s p in a n a lyse s a re

e x tre m e ly c o m p lic a te d , and (-Li.) th e y do n o t m ix s ig n i f i c a n t l y

w ith th e HF s ta te ( v . T ab le X I I ) . An in c lu s io n o f th e t o t a l

2 - p a r t ic le /2 - h o le space w i l l un d o u b te d ly a l t e r th e p o s i t io n

o f th e le v e ls in t h is band.

121

Page 179: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F ig u re 20. C a lc u la te d and e x p e rim e n ta l s p e c tra o f Magnesium 24. The spectrum la b e le d (a ) HF i s th e energy le v e ls p ro je c te d from th e H a rtre e -F o c k s ta te . The spectrum la b e le d (b ) l p - l h in c lu d e s a d ia g o n a liz a t io n o f a l l 1 - p a r t i c le / l - h o le s ta te s co n s id e re d w ith th e H a rtre e -F o c k s ta te ; th a t la b e le d (c )2p-2h In c lu d e s a d ia g o n a liz a t io n o f a l l 2 - p a r t ic le /2 - h o le s ta te s co n s id e re d w ith th e H a rtre e -F o c k s ta te . The spectrum la b e le d (d ) T o ta l in c lu d e s an e xa c t d ia g o n a l iz a t io n . o f b o th l p - l h and 2p-2h e x c i ta t io n s c o n s id e re d w ith th e HF s ta te .The e x p e r im e n ta l p o s i t iv e p a r i t y spectrum is la b e le d (e )E x p t. L e ve ls a re la b e le d by a n g u la r momentum and is o s p in (J , T ) .

Page 180: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

lp-lh

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Page 181: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T a b l e XI I

W a v e F u n c t i o n C o m p o s i t i o n of L o w - l y i n g

M a g n e s i u m 24 S t a t e s

J( T) H F l p - p h(1/2')

l p - l h(1/2")

l p - l h (3/2')

2 p - 2 h(1/2')

2 p - 2 h(1/2")

2p -2h(3/2')

E x c i tE n e r g

0(0) .9945 .0437 .0002 .0099 .0685 .0604 .0239 0 . 00

2(0) .9955 .0568 - .0071 .0090 .0553 .0451 .0217 0 . 6 3

4(0) .9940 .0910 - .0214 .0218 .0365 .0348 .0153 1 . 8 7

6(0) .9938 .0992 - .0071 .0451 .0179 .0100 .0044 3 . 55

8(0) .9852 .0547 - .1285 .0779 .0412 .0455 - . 0 0 8 1 5 . 5 2

0(0) - . 0 4 0 1 .8333 - .5444 - .0684 .0117 .0532 - . 0 0 8 6 6 . 4 9

2(0) - . 0 5 0 9 •8539 - .5143 - .0376 - .0416 . 0 2 3 0 .0032 7 . 0 8

4(0) - . 0 8 4 9 .7872 - .6033 .0508 - .0707 .0386 - . 0 0 0 6 7 . 5 8

4(1) - .9111 .0812 .2227 - •3360 - .0270 - . 0 0 4 5 8 . 24

2(1) - .9526 .0268 .1713 - .2486 - .0003 .0254 8 . 4 1

3(1) - .9453 - .0740 .3083 - .0760 .0119 .0031 8 . 50

6(0) .0703 - . 6 5 0 7 .7456 - .0451 .1165 - .0098 .0100 8 . 5 3

8(0) .1346 - . 2 9 4 7 .9376 .0284 .1079 - .0585 .0057 8 . 5 4

0(1) - .9868 .0304 .0852 - .1191 .0322 .0529 8 . 7 2

5(0) - .9537 - . 0 2 1 8 .2999 - - - 8 . 74

5(1) - .9411 - .0484 .3266 - .0618 .0370 . 0 10 1 8 . 78

1(1) - .9885 - .0507 .1309 - .0515 - . 0 2 1 6 - . 0 6 1 6 8 . 8 9

3(0) - .9879 .0163 .1540 - - - 9 . 0 1

10(0) .9766 - - .0081 - .1961 .0872 - . 0 0 9 0 9 . 0 1

6(1) - .9085 .1444 .2050 - .3302 - .0509 - . 0 0 6 7 9 . 0 3

1(0) - .9692 .0906 - ,2290 - - - 9 . 2 2

7(0) - .9694 - .0933 .2270 - - - 9 . 2 7

4(0) - . 0 3 1 3 .5602 .7732 .2276 - .1833 - .0444 - . 0 0 0 3 9 . 3 9

6(0) - . 0 7 2 0 .6775 .6459 .2795 - .2002 - .0117 .0147 9 . 5 2

10(0) - . 1 6 0 6 - - .5083 - .8275 - .1228 - . 1 2 6 4 9 . 69

0(0) - . 0 0 5 6 .4773 .7736 - .3947 - .1260 - .0407 - . 0 1 7 8 9 . 90

12(0) 1 — - - - - - 1 1 . 3 3

0(2) — — - - .9819 .1767 .0683 1 1 . 4 1

2(2) — - - - .9982 .0572 .0196 1 2 . 4 4

4(2) — — - - .9948 .0938 1 • 0 u> CO 1 2 . 9 7

6(2) — — - - .9992 .0208

COC\lon01 1 3 . 1 4

8(2) — - - - .9643 .2611 .0439 13 . 4 2

10(2) - - - - .8174 - .5607 .1316 1 3 . 4 7

12(2) _ — - .8008 - .5990 - 1 4 . 0 6

Page 182: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

122

s c h e m e h a s b e e n p e r f o r m e d b y B e r n i e r a n d H a r v e y 69 i n an

28a t t e m p t to d e s c r i b e a l l of th e l o w - l y i n g s t a t e s of Si

SU^, h o w e v e r , is u n a b l e t o e x p l a i n the o b s e r v e d e x p e r i m e n t a l

s p e c t r u m . In fact , f o r a p u r e q u a d r u p o l e - q u a d r u p o l e f o rc e ,

it l e a d s to a p a i r o f o r t h o g o n a l d e g e n e r a t e r e p r e s e n t a t i o n s

at l o w e n e r g y (cf. s e c t i o n I I I . 4 ) , a s i t u a t i o n w h i c h is n o t

e x p e r i m e n t a l l y o b s e r v e d . T h e tw o d e g e n e r a t e r e p r e s e n t a t i o n s

a r e a s s o c i a t e d w i t h q u a d r u p o l e m o m e n t s o f o p p o s i t e s i g n

(cf. b e l o w ) . T h e m o d e l d o e s , h o w e v e r , p r e d i c t t h e e x i s t e n c e

o f l o w - l y i n g J = 3 + l e v e l s , w h i c h ar e o b s e r v e d e x p e r i m e n t a l l y

(v. F i g u r e 21e). B a r - T o u v a n d K e l s o n 68 c o n s i d e r e d t h e g r o u n d

? fts t a t e o f Si to be d e f o r m e d , t a k i n g th e a b s o l u t e m i n i m u m

7 0(o bl a t e ) s o l u t i o n f r o m H F c a l c u l a t i o n s a n d a p p l y i n g th e I n g l i s

c r a n k i n g f o r m u l a f o r a d e t e r m i n a t i o n of th e m o m e n t o f i n e r t i a

o f t h e g r o u n d s t a t e b a nd . T h i s m e t h o d e f f e c t e d th e c o r r e c t

p r e d i c t i o n o f t h e f i r s t e x c i t e d J= 2 s t a t e at 1 . 77 M e V e x c i t a ­

t i o n e n e r g y . Da s G u p t a a n d H a r v e y 71 e x t e n d e d th e w o r k o f

B a r - T o u v a n d K e l s o n i n c o n s i d e r i n g t h e n e a r b y ('vl M e V h i g h e r )

p r o l a t e " l o c a l m i n i m u m " , a n d a l s o a T a m m - D a n c o f f a p p r o x i m a t i o n

a p p l i e d t o t h e o b l a t e s o l u t i o n . T h e y , h o w e v e r , f o u n d it t o o

d i f f i c u l t t o p e r f o r m t h e a c t u a l p r o j e c t i o n s , a n d i n s t e a d a s s u m e d

a r o t a t i o n a l c h a r a c t e r ~ E j = A + B J ( J + 1 ) f o r the s p e c t r u m . T h e i r

r e s u l t s , p a r a m e t e r i z e d b y th e s t r e n g t h o f th e s p i n - o r b i t fo rc e,

w e r e in f a i r a g r e e m e n t w i t h the e x p e r i m e n t a l s p e c t r u m w h e n

m u l t i p l i e d b y a n i n e x p l i c a b l e f a c t o r o f 2.

d . S i l i c o n 28

An e x t e n s i v e c a l c u l a t i o n u s in g th e SU^ c l a s s i f i c a t i o n

Page 183: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

123

R e s u l t s of p a r t i c l e - h o l e m i x i n g c a l c u l a t i o n s p e r f o r m e d

28f o r Si a r e r e p o r t e d in F i g u r e 21 a n d T a b l e XI II . T h e g r o u n d

s t a t e q u a s i - r o t a t i o n a l b a n d ( F i g u r e 21a) s h o w s th e sa m e f a c ­

t o r o f 2 d i s c r e p a n c y w i t h the e x p e r i m e n t a l s p e c t r u m ( F i g u r e 21e)

as n o t e d a b o v e . T h e e x c i t e d s t r u c t u r e s , h o w e v e r , u n l i k e

t h o s e o f Das G u p t a a n d H a r v e y , do not.

V a r i o u s e x p l a n a t i o n s h a v e b e e n o f f e r e d fo r t h e a p p e a r a n c e

o f th e l o w - l y i n g J= 0 l e v e l o b s e r v e d at 4. 97 M e V e x c i t a t i o n

e n e r g y . A l l o f t h e s e a s s o c i a t e th e l e v e l w i t h a n e q u i l i b r i u m

s h a p e o f the n u c l e u s , b u t t h e y d i f f e r as t o w h a t e q u i l i b r i u m

s h a p e is r e p r e s e n t e d . T h e p o s s i b l e s h a p e s , a l l a x i a l l y s y m ­

m e t r i c , c o v e r t h e f u l l r a n g e , i . e. , s p h e r i c a l 7 2 , o b l a t e 7 1 ,

a n d a m i x t u r e o f p r o l a t e a n d o b l a t e 7 3 .

B a r - T o u v a n d G o s w a m i 72 a t t r i b u t e t h i s l e v e l t o " i n v e r t e d

c o e x i s t e n c e " , i. e . , th e e x i s t e n c e o f a s p h e r i c a l e q u i l i b r i u m

s h a p e * , h i g h e r i n e n e r g y t h a n the d e f o r m e d g r o u n d st ate.

B a s e d o n an e l e m e n t a r y t h e o r y of s h a p e m i x i n g b e t w e e n the

s p h e r i c a l J= 0 l e v e l a t 4 . 97 M e V , a n d the o b l a t e g r o u n d st a t e ,

t h e y p r e d i c t e d a l o w e r i n g o f the c a l c u l a t e d (by p r o j e c t i o n )

g r o u n d s t a t e , a n d t h e r e b y an i n c r e a s e in th e e x c i t a t i o n o f the

J = 2 le ve l , W h e n t h i s is do ne, the g r o u n d s t a t e fa l l s r i g h t

i n t o p o s i t i o n i n a J( J+ 7) s p e c t r u m (v. F i g u r e 21f).

E x p e r i m e n t s 7 ** h a v e s h o w n an e n h a n c e m e n t (8 W e i s s k o p f

U n i t s ) f o r th e B ( E 2 ) t r a n s i t i o n f r o m th e J= 0 l e v e l at 4. 9 7 M e V

* W e n o t e t h a t th is s p h e r i c a l s t a t e is n o t the s p h e r i c a l HF s o l u t i o n o b t a i n e d b y f i l l i n g th e I d c / v s u b s h e l l , w h i c h liess o m e 30 M e V a b o v e th e l o w e s t o b l a t e s o l u t i o n . T h e s t a t e c o n s i d e r e d h e r e c o n t a i n s a d d i t i o n a l p a i r i n g i n t e r a c t i o n s . 4

Page 184: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

e x c i t a t i o n e n e r g y to th e J = 2 l e v e l at 1 . 77 M e V e x c i t a t i o n

e n e r g y (v. F i g u r e 21e). Da s G u p t a a n d H a r v e y h a v e i n f e r r e d

f r o m t h i s t h a t th e 4 . 97 M e V l e v e l m u s t b e o b l a t e , as is th e

g r o u n d s t a t e , s i n c e th e E 2 t r a n s i t i o n o p e r a t o r is a s i n g l e ­

p a r t i c l e o p e r a t o r a n d t h us c a n n o t c o n n e c t s t a t e s w h i c h a r e

h i g h l y d i f f e r e n t i n t h e i r s t r u c t u r e , e . g . , s p h e r i c a l or p r o ­

l a t e vs. o b l a t e . T h e J=0 l e v e l at 6 . 6 8 M e V e x c i t a t i o n e n e r g y

d o e s h a v e a n i n h i b i t e d E2 t r a n s i t i o n to th e J = 2 l e v e l at

1 . 7 7 M e V 7 \ so th i s , t h e y a r g u e , is th e s t a t e w i t h w h i c h to

a s s o c i a t e t h e p r o l a t e e q u i l i b r i u m s h a p e (cf. s e c t i o n I V . 4).

I n l i n e w i t h t h i s a s s o c i a t i o n o f t h e J= 0 l e v e l at 6 . 6 8

M e V w i t h th e p r o l a t e e q u i l i b r i u m s h a p e , C a s t e l a n d S v e n n e 73

a t t r i b u t e t h e 4 . 97 M e V l e v e l w i t h a m i x t u r e of t h e p r o l a t e

a n d o b l a t e e q u i l i b r i u m s h a p e s . T h e i r m o d e l d e s c r i b e s t w o

v i b r a t i o n s , on e a b o u t e a c h of th e d e f o r m e d H F m i n i m a , c o u p l e d

t h r o u g h t h e i r q u a d r u p o l e f i e l d s . T h e b a s i s s p a c e fo r the

c a l c u l a t i o n s c o n s i s t e d of th e 1-6, Ip, 2 6 Id, a n d * 1(7 / 2 o s c il ~

l a t o r s h e l l s . As a t w o - b o d y i n t e r a c t i o n , th e e f f e c t i v e p o ­

t e n t i a l o b t a i n e d f r o m th e K u o - B r o w n 75 G - m a t r i x c a l c u l a t e d

w i t h t h e H a m a d a - J o h n s t o n p o t e n t i a l 5 w a s u s e d , r a t h e r t h a n the

m o r e e l e m e n t a r y p h e n o m e n o l o g i c a l i n t e r a c t i o n u s e d i n t h e s e

c a l c u l a t i o n s . T h e i r r e s u l t s for t h e i n t e r m e d i a t e s t r u c t u r e

P 8o f Si a r e p r e s e n t e d i n F i g u r e 21f. As s h o w n , t h e y a g r e e

a m a z i n g l y w e l l w i t h t h e o b s e r v e d s p e c t r u m .

T h e c a l c u l a t i o n s r e p o r t e d h e r e p r e d i c t the a p p e a r a n c e

o f t h e l o w e s t J= 0 l e v e l at a p p r o x i m a t e l y 7*5 M e V e x c i t a t i o n

e n e r g y . In fa c t , w e p r e d i c t t w o q u a s i - r o t a t i o n a l b a n d s w h i c h

124

Page 185: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

a r e n e a r l y d e g e n e r a t e i n t h e i r b a n d h e a d e n e r g i e s , ( w i t h i n

40 K e V) b u t w h i c h h a v e m o m e n t s o f i n e r t i a w h i c h d i f f e r b y

a f a c t o r o f a p p r o x i m a t e l y 2 ( b a s e d on th e e n e r g y o f the

e x c i t e d J= 2 l e v e l s r e l a t i v e to t h e b a n d h e a d e n e r g i e s ) .

A n a l y s e s of w a v e f u n c t i o n s o f t h e s e b a n d s (v. T a b l e X I I I )

s h o w s t h a t t h e y b o t h a r i s e f r o m 1 - p a r t i c l e / l - h o l e e x c i t a t i o n s

o f t h e o b l a t e s o l u t i o n , a n d n o t, as m i g h t b e s u s p e c t e d f r o m

t h e a b o v e d i s c u s s i o n s , on e e a c h f r o m the o b l a t e a n d p r o l a t e

s o l u t i o n s . If th i s w e r e the ca se, w e w o u l d e x p e c t to see

s i g n i f i c a n t a d m i x t u r e s f r o m th e 2 - p a r t i c l e / 2 - h o l e c o n f i g u r a ­

t i o n s f o r the p r o l a t e b a n d . T h i s is no t the case. O n e b a n d

(w it h t h e s m a l l e r v a l u e o f the m o m e n t of i n e r t i a ) h a s as a

m a j o r c o m p o n e n t the 1 - p a r t i c l e / l - h o l e c o n f i g u r a t i o n k = l / 2 f

(v. T a b l e IX), th e o t h e r th e 1 - p a r t i c l e / l - h o l e c o n f i g u r a t i o n

k = 3 / 2 ' , t h e s e at l o w e n e r g y r e l a t i v e to the b a n d h e a d s . At

t h e h i g h a n g u l a r m o m e n t u m s t a t e s o f the b a n d s , t h i s s e p a r a t i o n

is n o l o n g e r m e a n i n g f u l , h o w e v e r , a n d th e b a n d s ar e h i g h l y

m i x e d .

T h e e x p e r i m e n t a l J = 3 + l e v e l at 6 . 2 8 M e V e x c i t a t i o n e n e r g y

is b e l i e v e d to be a s s o c i a t e d w i t h a K = 3 r o t a t i o n a l b a nd . As

d i s c u s s e d i n s e c t i o n I V . 6 c , t h i s s t r u c t u r e c a n n o t b e r e a c h e d

b y th e c o n f i g u r a t i o n s c o n s i d e r e d h e r e , b u t th e g e n e r a l m e t h o d s

m a y b e a p p l i e d t o m a k e p r e d i c t i o n s c o n c e r n i n g t h is ba nd.

E x a m i n a t i o n o f F i g u r e 2 1 d a l s o r e v e a l s the p r e s e n c e of a

T=2 q u a s i - r o t a t i o n a l b a n d at a p p r o x i m a t e l y 1 3 .9 M e V e x c i t a t i o n

e n e r g y . T h i s o f c o u r s e , a r i s e s as a r e s u l t of 2 - p a r t i c l e / 2 -

h o l e c o n f i g u r a t i o n s , a n d is e x p e c t e d to u n d e r g o e n e r g y s h i f t s

w h e n th e c o m p l e t e s p a c e o f 2 p - 2 h c o n f i g u a t i o n s is c o n s i d e r e d .

125

Page 186: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F i g u r e 21. C a l c u l a t e d a n d e x p e r i m e n t a l s p e c t r a o f S i l i c o n 28.

T h e s p e c t r u m l a b e l e d (a) HF is th e e n e r g y l e v e l s p r o j e c t e d

f r o m t h e H a r t r e e - F o c k s t a t e . T h e s p e c t r u m l a b e l e d (b) l p - l h

i n c l u d e s a d i a g o n a l i z a t i o n o f a l l 1 - p a r t i c l e / l - h o l e s t a t e s

c o n s i d e r e d w i t h th e H F s t a t e ; t h a t l a b e l e d (c) 2 p - 2 h i n c l u d e s

a d i a g o n a l i z a t i o n of a l l 2 p - 2 h s t a t e s c o n s i d e r e d w i t h the HF

s t a t e . T h e s p e c t r u m l a b e l e d (d) T o t a l i n c l u d e s a n e x a c t

d i a g o n a l i z a t i o n of b o t h l p - l h a n d 2 p - 2 h e x c i t a t i o n s c o n ­

s i d e r e d w i t h th e HF s t a t e . T h e e x p e r i m e n t a l p o s i t i v e p a r i t y

s p e c t r u m is l a b e l e d (e) E x p t . L e v e l s a r e l a b e l e d b y a n g u l a r

m o m e n t u m a n d i s o s p i n (J,T). T h e r e s u l t s o f tw o s h a p e - m i x i n g

c a l c u l a t i o n s a r e r e p o r t e d i n (f). T h e s e a r e b y B a r - T o u v

a n d G o s w a m i 72 a n d C a s t e l a n d S v e n n e 7 3 .

Page 187: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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Page 188: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T a b l e X I I I

W a v e F u n c t i o n C o m p o s i t i o n of L o w - l y i n g

S i l i c o n 28 S t a t e s

J ( T) HF l p - l h(3/2'

l p - l h ) (1/2')

l p - l h(1/2")

2 p - 2 h(3/2')

2 p - 2 h (1/2')

2 p - 2 h(1/2"

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0(0) .9947 .0546 .0115 .0767 .0317<0 20 1—10• . 0 163 0 . 00

2(0) .9953 .0530 .0129 .0712 .0288 .0154 .0176 0.70

4(0) .9954 .0414 .0296 .0691 .0266 .0186 .0259 2.29

6(0) .9956 .0275 .0450 .0606 .0218 .0263 .0349 4.76

0(0) - . 0 6 1 3 .9766 .1877 .0812 - . 0 2 4 8 .0010 .0043 7.48

0(0) - . 0 3 6 0 - . 2 0 5 6 .8646 .4481 .0145 . 0 7 7 0 .0450 7 . 5 2

8(0) .9970 .0082 .0414 .0433 .0161 .0286 .0368 7. 99

2(0) - . 0 6 9 2 .8071 .5175 .2717 - . 0 2 6 7 .0323 .0194 8 . 0 3

1(0) - .9939 - . 1 0 8 8 .0161 - - - 8 . 1 4

0(1) - .9874 .1373 - . 0 5 3 5 - . 0 5 5 8 .0159 .0032 8 . 4 4

2(0) - . 0 0 7 4 - . 5 8 7 4 .7062 .3922 .0095 .0379 .0295 8 . 4 6

1(1) - .9825 - . 1 8 2 3 .0332 .0135 - .0103 -

^T<NOO• 8 . 7 2

2(1) - .9868 .1330 - . 0 4 8 8 - . 0 7 7 8 .0135 .0004 8 . 9 7

3(0) - .9950 - . 0 9 4 0 .0334 - - - 9 . 1 4

4(0) - . 0 7 5 4 .5526 . 6 9 8 9 .4454 - . 0 2 1 2 . 0 3 2 2 .0257 9 . 1 6

3(1) - .9818 - . 1 8 2 0 .0523 . 0 1 1 8 - .0122 .0007 9 . 7 3

4(0) .0024 .8315 - . 4 5 6 7 - . 3 1 3 7 - . 0 2 8 7 - .0153 - .0212 9 . 90

4(1) - .9852 .1295

-=r00cvj0•1 - . 1 0 8 6 .0013 .0009 1 0 . 2 0

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Page 189: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

126

e. S u l f u r 32

T h e r e s u l t s o f p a r t i c l e - h o l e m i x i n g c a l c u l a t i o n s f o r S 32

a r e r e p o r t e d i n F i g u r e 22 a n d T a b l e XIV. F i g u r e 2 2 f r e p r e s e n t s

t h e w o r k o f F a r r i s a n d E i s e n b e r g 7 6 . T h e y c o n s i d e r the g r o u n d

32s t a t e c o n f i g u r a t i o n of S to be th e c l o s e d ^ ^ 5 / 2 _7,&7/2 s u b ~

s h e l l s , a n d p e r f o r m e d p a r t i c l e - h o l e 1 c a l c u l a t i o n s o n t h is

s p h e r i c a l c o n f i g u r a t i o n . E x a m i n a t i o n of t h e i r r e s u l t s s h o w s

t h a t t h e y h a v e a c c o u n t e d f o r m o s t of th e e i g e n s t a t e s , b u t

c a n n o t p r o d u c e n u m e r i c a l a g r e e m e n t w i t h the o b s e r v e d e x c i t a ­

t i o n e n e r g i e s (v. F i g u r e 22e). A p a r t i c u l a r l y w e a k p o i n t in

t h e i r r e s u l t s is t h e i n a b i l i t y to a c c o u n t fo r t h e 2- p h o n o n

v i b r a t i o n s t r u c t u r e at a p p r o x i m a t e l y 4-5 M e V e x c i t a t i o n e n e r g y

(v. F i g u r e 22e).

32T a b l e I X s h o w s t h a t the p r o l a t e HF s o l u t i o n f o r S J is

o n l y s l i g h t l y (by 3 6 0 KeV) f a v o r e d o v e r th e o b l a t e s o l u t i o n .

A l t h o u g h t h e a x i a l l y a s y m m e t r i c s o l u t i o n is s o me 3 M e V b e l o w

th e a x i a l s o l u t i o n s , it is n o w k n o w n (v. s e c t i o n I V . 6c) t h a t

t h e l o w e s t H F s o l u t i o n is n o t n e c e s s a r i l y r e p r e s e n t a t i v e of

th e b e s t d e s c r i p t i o n o f the n u c l e u s i n t e r m s o f a n i n t r i n s i c

st a t e . In v i e w of t h i s , a n d c o n s i d e r i n g th e cl o s e s i m i l a r i t y

?4 32o f th e b e h a v i o r o f t h e H F e n e r g y s u r f a c e s 68 o f M g a n d S ,

it w a s d e c i d e d to p e r f o r m p a r t i c l e - h o l e m i x i n g c a l c u l a t i o n s

32o n th e l o w e s t a x i a l l y s y m m e t r i c p r o l a t e s o l u t i o n s o f S

T h e b a r e H F s o l u t i o n , b e i n g r e p r e s e n t a t i v e o f a p e r m a ­

n e n t l y d e f o r m e d p r o l a t e s h a p e , y i e l d s a r o t a t i o n a l s p e c t r u m

( F i g u r e 22a). S 32 is n o t, h o w e v e r , d e s c r i b e d as a r o t a t i o n a l

n u c l e u s , b u t r a t h e r as v i b r a t i o n a l , e x h i b i t i n g th e t y p i c a l

Page 190: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

J = 0 , 2, 0 - 2 - 4 e x c i t a t i o n s p e c t r u m ® . T h e t r a n s f o r m a t i o n f r o m

a r o t a t i o n a l d e s c r i p t i o n to a v i b r a t i o n a l one is e f f e c t e d b y

the 1 - p a r t i c l e / l - h o l e a d m i x t u r e s t o th e H F s t a t e (v. F i g u r e 22b),

a l t h o u g h t h e r e is s o m e m i x i n g w i t h 2 - p a r t i c l e / 2 - h o l e c o n f i g u ­

r a t i o n s (v. T a b l e XIV) . T h e l p - l h e x c i t a t i o n s c a u s e a n i n ­

c r e a s e in th e e x c i t a t i o n e n e r g y o f the l o w e s t J = 2 le vel, as

it s d e s c r i p t i o n c h a n g e s f r o m b e i n g p a r t of a r o t a t i o n a l b a n d

t o t h a t o f a 1 - p h o n o n e x c i t a t i o n . In a d d i t i o n , a J= 0 a n d

J = 2 l e v e l a p p e a r in t h e v i c i n i t y of th e l o w e s t J = 4 s t a t e

(the e x c i t a t i o n e n e r g y o f w h i c h Is r a i s e d o v e r t h e p u r e HF

v a l u e ) , p r o d u c i n g th e J = 0 - 2 - 4 t r i p l e t o f the 2 - p h o n o n e x c i t a ­

tion .

127

T h e J= 2 l e v e l a c t u a l l y lies s o m e 2.5 M e V h i g h e r t h a n the J = 0 a n d J= 4 l e v e ls . T a b l e X I V s h o w s t h a t the w a v e f u n c t i o n of t h i s l e v e l ha s s o m e a d m i x t u r e f r o m the 2 p - 2 h s t a t e s c o n s i d e r e d .It is b e l i e v e d t h a t w h e n th e e n t i r e s p a c e of 2 p - 2 h c o n f i g u r a t i o n s is c o n s i d e r e d , t h i s l e v e l w i l l be l o w e r e d i n t o th e v i c i n i t y of th e t r i p l e t .

Page 191: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F i g u r e 22. C a l c u l a t e d a n d e x p e r i m e n t a l l o w - e n e r g y s p e c t r a

o f S u l f u r 32. T h e s p e c t r u m l a b e l e d (a) HF is th e e n e r g y

l e v e l s p r o j e c t e d f r o m the H a r t r e e - F o c k s t a t e . T h e s p e c t r u m

l a b e l e d (b) l p - l h i n c l u d e s a d i a g o n a l i z a t i o n o f a l l 1 - p a r t i c l e /

1 - h o l e s t a t e s c o n s i d e r e d w i t h th e H a r t r e e - F o c k s t a t e ; t h at

l a b e l e d (c) 2 p - 2 h i n c l u d e s a d i a g o n a l i z a t i o n of a l l 2 - p a r t i c l e /

2 - h o l e s t a t e s c o n s i d e r e d w i t h th e H a r t r e e - F o c k s t a t e . T h e

s p e c t r u m l a b e l e d ( d ) T o t a l i n c l u d e s a n e x a c t d i a g o n a l i z a t i o n of

b o t h l p - l h a n d 2 p - 2 h e x c i t a t i o n s c o n s i d e r e d w i t h the H F st a t e .

T h e e x p e r i m e n t a l p o s i t i v e p a r i t y l o w - e n e r g y s p e c t r u m is

l a b e l e d (e) E x p t . L e v e l s a r e l a b e l e d b y a n g u l a r m o m e n t u m a n d

i s o s p i n (J , T ) .

Page 192: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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Page 193: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T a b l e X I VW a v e F u n c t i o n C o m p o s i t i o n of L o w - l y i n g

S u l f u r 32 S t a t e s

J ( T) HFl p - l h(1/2*)

l p - l h(3/2*)

l p - l h(1/2")

2 p - 2 h (1/2*)

2 p - 2 h(3/2*)

2 p - 2 h(1/2")

E x c i t . E n e r g y

0 (0 ) .8651 .3107 .1137 - . 3 5 7 4 .0902 .0138 .0774 0 . 0 0

2(0) .9874 .1269 .0862 - . 0 0 7 7 . 0 3 2 2 .0191 .0043 1 . 95

0(0) .4638 - . 3 2 8 4 .0199 .8189 - . 0 5 8 3 .0167 - . 0 4 8 0 2 . 9 1

4(0) .9187 .2854 .0704 - . 2 4 8 3 .0629 .0228 .0586 3.49

2(0) .0608 - . 4 0 5 7 -.008t| .9112 - . 0 3 2 0 .0067 .0193 6 . 37

6(0) .9485 . 2 3 2 1 .0454 - . 2 0 3 9 .0086 .0155 .0496 6 . 8 4

4(0) .3837 - . 5 6 1 0 - . 0 4 7 0 .7192 - . 0 5 3 5 .0097 - . 1 2 5 2 6 . 9 5

1(1) - - . 0 8 9 5 .0494 .9730 - . 0 3 9 0 - . 0 0 6 2 - . 2 0 3 0 7 . 5 0

0(2) - - - - .1687 .0562 .9841 7 . 50

1(0) - .0112 .0213 . 9 9 9 1 - - - 8 . 1 0

0(1) - .0383 - . 2 3 3 3 .9683 - . 0 4 9 8 .0331 .0544 8 . 1 3

2(1) - .0777 - . 1 7 4 4 .9398 - . 1 1 7 2 .0002 - . 2 5 8 1 8 . 3 0

8(0) .8242 .2225 - . 3 2 8 5 - . 3 0 5 7 .2607 .0423 - 8 . 5 2

3(1) - .0755 . 2 3 0 1 .9658 .0185 - . 0 0 0 5 - . 0 9 0 7 9 . 4 9

3(0) - .0502 .1775 .9828 - - - 9 . 8 4 .

4(1) - .5243 .0738 .7223 - . 0 0 1 4 - . 0 2 1 1 - . 4 4 4 4 1 0 . 1 1

0(0) - . 0 9 7 2 .8219 - . 3 5 6 9 .4059 .1440 - . 0 4 0 0 .0248 1 0 . 8 7

2(0) - . 0 8 1 0 .8552 - . 3 2 0 1 .3872 .0765 - . 0 0 9 8 - . 0 6 1 4 1 1 . 1 2

Page 194: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

128

f . A r g o n 36

T h e H F s p a c e u s e d in th e p a r t i c l e - h o l e m i x i n g c a l c u l a t i o n s

f o r A r -5 is t h a t l i s t e d in T a b l e IX, w h i c h Is a s s o c i a t e d w i t h

a n o b l a t e d e f o r m a t i o n . M u t h u k r i s h n a n 8 3 h a s o b t a i n e d a p r o l a t e

s o l u t i o n u s i n g a n o n - l o c a l p o t e n t i a l w h i c h a c ts o n l y i n r e l a ­

t i v e s - s t a t e s . T h i s s o l u t i o n lies s o m e 6.5 M e V a b o v e th e o b l a t e

s o l u t i o n o b t a i n e d f o r t h e s a m e i n t e r a c t i o n .

T h e r e s u l t s o f m i x i n g c a l c u l a t i o n s a r e r e p o r t e d in F i g u r e

23. A s d e p i c t e d , the 1 - p a r t i c l e / l - h o l e e x c i t a t i o n s m i x w i t h

t h e H F s o l u t i o n to y i e l d b e t t e r a g r e e m e n t o f th e g r o u n d s t a t e

q u a s i - r o t a t i o n a l b a n d w i t h th e l o w - l y i n g e x c i t a t i o n s p e c t r a

o b s e r v e d e x p e r i m e n t a l l y . I n a d d i t i o n , a l s o a r i s i n g f r o m the

l p - l h c o n f i g u r a t i o n s is a l o w - l y i n g J = 0 l e v e l at a p p r o x i m a t e l y

4.9 M e V. A r o t a t i o n a l b a n d s t r u c t u r e is b u i l t on th is le ve l.

T h e r e is c o n s i d e r a b l e e v i d e n c e t h a t t h e e q u i l i b r i u m

s h a p e o f th e g r o u n d s t a t e o f A r 3^ is s p h e r i c a l , r a t h e r t h a n

d e f o r m e d , as s u g g e s t e d b y H F r e s u l t s . T h e p a r t i c l e - h o l e

m i x i n g c a l c u l a t i o n s p e r f o r m e d h e r e c l e a r l y s h o w t h e e x i s t e n c e

o f t h e 2 - p h o n o n t r i p l e t , w h i c h e x p e r i m e n t a l l y lies at ^ 4 . 4

M e V e x c i t a t i o n e n e r g y . Its t h e o r e t i c a l d e s c r i p t i o n as a

r o t a t i o n a l s t r u c t u r e is, h o w e v e r , i n e s c a p a b l e . C l e a r l y , HF

t h e o r y f a i l s t o d e s c r i b e t h i s n u c l e u s .

\

Page 195: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F i g u r e 23. C a l c u l a t e d a n d e x p e r i m e n t a l l o w - e n e r g y s p e c t r a

o f A r g o n 3 6 . T h e s p e c t r u m l a b e l e d (a)HF is th e e n e r g y

l e v e l s p r o j e c t e d f r o m th e H a r t r e e - F o c k s t a t e . T h e s p e c t r u m

l a b e l e d (b) l p - l h i n c l u d e s a d i a g o n a l i z a t i o n o f a l l 1 - p a r t i c l e /

1 - h o l e s t a t e s c o n s i d e r e d w i t h the H a r t r e e - F o c k s t a t e ; th a t

l a b e l e d (c) 2 p - 2 h i n c l u d e s a d i a g o n a l i z a t i o n o f a l l 2 - p a r t i c l e /

2 - h o l e s t a t e s c o n s i d e r e d w i t h th e H a r t r e e - F o c k s t a t e . T h e

s p e c t r u m l a b e l e d (d) T o t a l i n c l u d e s a n e x a c t d i a g o n a l i z a t i o n of

b o t h l p - l h a n d 2 p - 2 h e x c i t a t i o n s c o n s i d e r e d w i t h th e H F st ate.

T h e e x p e r i m e n t a l p o s i t i v e p a r i t y l o w - e n e r g y s p e c t r u m is

l a b e l e d (e) E x p t . L e v e l s ar e l a b e l e d by a n g u l a r m o m e n t u m a n d

i s o s p i n (J,T).

Page 196: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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Page 197: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T a b l e X V

W a v e F u n c t i o n C o m p o s i t i o n of L o w - l y i n g

A r g o n 36 S t a t e s

J H F •l p - l h (1/2')

l p - l h (1/2")

2 p - 2 h(1/2')

2 p - 2 hCl/2")

E x c i tEnerg;

0 ,9&24 - . 0 3 7 0 - . 2 6 4 4 .0124 - . 0 4 8 1 0. 00

2 .9850 .0361 - . 1 6 4 3 . 0 2 1 7 .0316 1 . 5 1

4 .9754 - . 0 9 1 5 - . 1 9 3 0 . 0 0 3 5 .0542 3 . 50

0 .1230 .9408 .3083 .0417 - . 0 5 5 3 4 . 84

2 .0111 .9619 .2631 - . 0 6 7 4 - . 0 3 0 5 6 . 4 8

6 .9801 .1551 - . 1 0 3 6 .0684 - 7 . 5 3

4 .1784 .8250 .5113 - . 1 6 0 9 - . 0 1 2 1 8 . 74

Page 198: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

H a r t r e e - F o c k s o l u t i o n s o f th e e v e n - e v e n N = Z n u c l e i in

the 2 4 - / d s h e l l h a v e b e e n s t u d i e d . T h e f o l l o w i n g g e n e r a l

c o n c l u s i o n s h a v e b e e n d i s c u s s e d :

( i . ) T h e m a n i f e s t a t i o n o f a n e n e r g y g a p b e t w e e n o c c u p i e d

a n d u n o c c u p i e d HF o r b i t a l s is du e to a p a r t i c u l a r c o m b i n a t i o n

(v. e q u a t i o n (I V - 2 2 ) ) o f e x c h a n g e p o t e n t i a l s , d o m i n a t e d b y

th e s p a t i a l e x c h a n g e ( M a j o r a n a ) term. It t h us r e f l e c t s th e

e m p l o y m e n t of a n o n - l o c a l s e l f - c o n s i s t e n t p o t e n t i a l .

24( l - L ) T h e a s y m m e t r y o f th e l o w e s t HF s o l u t i o n s of M g

32a n d r e f l e c t a p r e f e r e n c e o f th e H F f i e l d fo r s p a t i a l ,

r a t h e r t h a n a x i a l s y m m e t r y . I n t h e o t h e r e v e n - e v e n N=Z

n u c l e i o f t h e 2 4 - I d s h e l l , t h e t w o s y m m e t r i e s ar e c o m p a t i b l e .

( U l ) P a r t i c l e - h o l e c o n f i g u r a t i o n s h a v e b e e n s h o w n t o

r e p r e s e n t a p o s s i b l e a d m i x t u r e t o t h e l o w - l y i n g H F s o l u t i o n s .

P r o j e c t i o n c a l c u l a t i o n s h a v e b e e n c a r r i e d ou t f o r th e

1- a n d 2 - p a r t i c l e - h o l e e x c i t a t i o n s of th e H F s t a t e s o f e v e n -

e v e n N = Z n u c l e i in t h e 2 6 - 1 d s h e l l to d e t e r m i n e t h e e x t e n t

o f t h e s e a d m i x t u r e s . T h e p o l y n o m i a l p r o j e c t i o n t e c h n i q u e s

d e v e l o p e d i n C h a p t e r II w e r e o f g r e a t a s s i s t a n c e i n p e r f o r m i n g

t h e s e c a l c u l a t i o n s , as w a s th e m e t h o d of p e r f o r m i n g c a l c u l a ­

t i o n s i n n o n - o r t h o n o r m a l H i l b e r t s p a c e s . T h e n e c e s s i t y to

s i m u l t a n e o u s l y p r o j e c t i s o s p i n a n d a n g u l a r m o m e n t u m w a s o b v i a t e d

b y th e c o n s t r u c t i o n of s i m p l e c o m b i n a t i o n s o f S l a t e r d e t e r m i n -

a n t a l s t a t e s w h i c h a l r e a d y h a d g o o d i s o s p i n . T h e f o l l o w i n g

r e s u l t s h a v e b e e n o b t a i n e d f r o m t h e s e c a l c u l a t i o n s :

129

7 . Summary

Page 199: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

130

(-t) A n g u l a r m o m e n t u m c o m p o n e n t s o f th e HF a n d p u r e

p a r t i c l e - h o l e c o n f i g u r a t i o n s h a v e c o n s i d e r a b l e o v e r l a p (v.

T a b l e X), a l t h o u g h H a m i l t o n i a n m i x i n g b e t w e e n th e H F c o m ­

p o n e n t s a n d a n o r t h o n o r m a l p a r t i c l e - h o l e b a s i s g e n e r a t e d

b y a S c h m i d t p r o c e d u r e a r e n e g l i g i b l e in th e f i r s t h a l f of

th e s h e l l , w h e r e r o t a t i o n a l p r o p e r t i e s a r e m o r e p r o m i n e n t

t h a n i n the l a t t e r h a l f .

{ aJ , ) T h e i n s t a b i l i t y of th e H F s o l u t i o n s f o r S 3 2 a n d

A r m a n i f e s t t h e m s e l v e s i n t h e a p p e a r a n c e o f a l o w - l y i n g

K = 0 q u a s i - r o t a t i o n a l b a n d (at ^ 3 a n d 5 M e V e x c i t a t i o n

e n e r g y , r e s p e c t i v e l y ) , w h i c h c a u s e s i g n i f i c a n t c h a n g e s i n

t h e l o w e n e r g y s p e c t r a w h e n m i x i n g is t a k e n i n t o a c c o u n t .

(-Let) P a r t i c l e - h o l e c o n f i g u r a t i o n s a c c o u n t f o r e x c i t e d

s t a t e s o f l o w a n g u l a r m o m e n t u m o b s e r v e d in a l l o f th e n u c l e i

u n d e r c o n s i d e r a t i o n , b u t n u m e r i c a l a g r e e m e n t wit-h t h e e x p e r ­

i m e n t a l e i g e n v a l u e s is n o t a c h i e v e d . T h i s is p r o b a b l y

b e c a u s e o f t h e l i m i t e d s h a p e m i x i n g w h i c h is i n t r o d u c e d b y

t h e p a r t i c l e - h o l e c o n f i g u r a t i o n s . It is c l e a r (cf. d i s c u s s i o n

P 8o f Si ) t h a t a n e x p l a n a t i o n o f th e l o w - e n e r g y p r o p e r t i e s of

t h e s e n u c l e i c a n o n l y b e a c h i e v e d w h e n the i n t e r a c t i o n a m o n g

th e v a r i o u s e q u i l i b r i u m s h a p e s is t a k e n i n t o a c c o u n t .

B a s e d o n the a b o v e , it c a n o n l y b e c o n c l u d e d t h a t w h i l e

H F is an e x t r e m e l y u s e f u l t o o l f o r t h e s t u d y of l o w - e n e r g y

n u c l e a r s t r u c t u r e , c o n s i d e r a b l e i m p r o v e m e n t is n e e d e d I f it

is t o y i e l d , w i t h o u t e x t e n s i v e c o m p l i c a t i o n s , q u a n t i t a t i v e

a g r e e m e n t w i t h e x p e r i m e n t a l data . T h e r e Is a p a r t i c u l a r i m ­

p r o v e m e n t w h i c h m a y p r o v e f r u i t f u l t o t h is end. W e n o t e t h at

Page 200: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

a v a r i a t i o n a l c a l c u l a t i o n is p e r f o r m e d w i t h i n s t e a d of

w i t h A v a r i a t i o n w i t h s h o u l d i n v o l v e th e a p p l i c a t i o n

o f a n i n t r i n s i c H a m i l t o n i a n r a t h e r t h a n the a c t u a l one.

T h e o n l y i n t r i n s i c H a m i l t o n i a n e m p l o y e d o f t h is n a t u r e is

H - I J 2 , w h e r e I is r e l a t e d to the m o m e n t o f i n e r t i a p a r a m e t e r .7 7

It h a s b e e n p o i n t e d o u t b y V i i l a r s t h a t t h e s t a t e s o b t a i n e d

b y p r o j e c t i n g out of ^ h a v e a J(J + / ) d e p e n d e n c e i n th e f i r s t

o r de r . T h e l o w - e n e r g y e x c i t a t i o n s p e c t r a is t h u s f o r c e d to

h a v e a r o t o r - l i k e s t r u c t u r e . As h a s b e e n s h o w n , t h i s is n o t

a l w a y s a p p r o p r i a t e , a n d w h e n it is, w e w o u l d p r e f e r to o b t a i n

it a s o u t p u t o f a c a l c u l a t i o n , r a t h e r t h a n as in pu t.

T h e s e o b j e c t i o n s a r e r e m o v e d , in p r i n c i p l e , i f the

v a r i a t i o n is p e r f o r m e d b y s o l v i n g t h e f o l l o w i n g e q u a t i o n for

e a c h J va l u e :

6[ < P J '1'K |H|PJ 4'K > / < P J 1'K |PJ 4'K > ] = 0,

i . e . , t h e c o e f f i c i e n t s c^ a r e v a r i e d a f t e r p r o j e c t i o n , r a t h e r

t h a n b e f o r e . C a l c u l a t i o n s to c o m p a r e w a v e f u n c t i o n s o f this

t y p e w i t h t h o s e p r o j e c t e d f r o m a n i n t r i n s i c HF s t a t e a f t e r

m i n i m i z a t i o n h a v e b e e n p e r f o r m e d b y S a t p a t h y a n d N a i r 7 8 . ..

T h e y h a v e f o u n d e s s e n t i a l l y n o d i f f e r e n c e i n th e w a v e f u n c -

20 20 t i o n s f o r Ne . H o w e v e r , as h a s b e e n n o t e d , Ne is a

r a t h e r u n i q u e n u c l e u s in th e 2 6 - I d s h e l l , i . e. , H F c a l c u l a t i o n s

20a g r e e r e m a r k a b l y w e l l w i t h e x p e r i m e n t a l d a t a ; Ne a l s o e x h i b i t s

m a r k e d r o t a t i o n a l p r o p e r t i e s , m u c h m o r e so t h a n th e n u c l e i

o f t h e l a t t e r h a l f of the s h e l l (v. s e c t i o n I V . 6). It is

s u g g e s t e d t h a t s u c h c a l c u l a t i o n s b e p e r f o r m e d in t h i s re g i o n .

W e e x p e c t t h a t the c o m p l i c a t i o n o f s h a p e - m i x i n g c a l c u l a t i o n s

f o r t h e s e n u c l e i w i l l be p r e c l u d e d b y m i n i m i z i n g a f t e r p r o j e c t i o n .

131

Page 201: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

132

C H A P T E R V

S U M M A R Y A N D C O N C L U S I O N S

T h e w o r k r e p o r t e d h e r e i n is a n a t t e m p t to e l u c i d a t e

the c o m p l e m e n t a r y r e l a t i o n s h i p b e t w e e n m a c r o s c o p i c a n d

m i c r o s c o p i c m o d e l s o f n u c l e a r s t r u c t u r e . T o t h i s e n d, a

s t u d y o f t h e d e v e l o p m e n t o f c o l l e c t i v i t y w i t h i n the f r a m e ­

w o r k o f a n i n d i v i d u a l - p a r t i c l e m o d e l , a n d o f i n d i v i d u a l -

p a r t i c l e m o t i o n s w i t h i n th e f r a m e w o r k -of a c o l l e c t i v e m o d e l

h a s b e e n u n d e r t a k e n . W e h a v e c o m e t o th e f o l l o w i n g c o n c l u ­

si on s:

(+) T h e q u a d r u p o l e - q u a d r u p o l e i n t e r a c t i o n g i v e s r i s e

to a n a t u r a l g r o u p i n g o f p a r t i c l e d e g r e e s o f f r e e d o m in

c o l l e c t i v e c o o r d i n a t e s . T h e s e m a n i f e s t t h e m s e l v e s in

e x c i t a t i o n s p e c t r a w h i c h m a y b e d e s c r i b e d b y a f e w c o l l e c t i v e

p a r a m e t e r s .

( i t ) T h e o b s e r v e d s y s t e m a t i c s h a p e t r a n s i t i o n s ( f r o m

s p h e r i c a l t o p r o l a t e , to o b l a t e , a n d f i n a l l y b a c k to s p h e r i c a l )

w h i c h o c c u r w i t h t h e a d d i t i o n of p a r t i c l e s to a n e m p t y sh e l l ,

a r e a c c o u n t e d f o r e x c l u s i v e l y by t h e l o n g r a n g e c o m p o n e n t of

t h e n u c l e o n - n u c l e o n i n t e r a c t i o n . T h i s h a s b e e n d e m o n s t r a t e d

i n ( / ) w c o n f i g u r a t i o n s ; t h e r e is s o m e e v i d e n c e t h a t t h i s is

n o t g e n e r a l l y th e c a s e i n th e m o r e r e a l i s t i c s h e l l m o d e l .

U U ) F o r ( / ) w c o n f i g u r a t i o n s , th e l o n g r a n g e p a r t of

t h e e f f e c t i v e i n t e r a c t i o n b r i n g s a b o u t a t e m p o r a r y s p h e r i c i t y

o f t h e n u c l e a r s u r f a c e a s s o c i a t e d w i t h the c h a n g e i n s i g n o f

th e q u a d r u p o l e m o m e n t In th e m i d d l e o f th e sh e l l .

Page 202: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

(-tv) T h e p a r t i c l e - t o - s u r f a c e c o u p l i n g m o d e l is o f

v a l u e i n d e s c r i b i n g t h e g r o u n d s t a t e o f m u l t i - p a r t i c l e

s y s t e m s o n th e b a s i s o f a c o l l e c t i v e d e s c r i p t i o n .

(v) T h e e x p e r i m e n t a l l y o b s e r v e d d i s t o r t i o n s o f r o t a ­

t i o n a l b a n d s at h i g h a n g u l a r m o m e n t u m Is d i r e c t l y a t t r i b u t e d

t o t h e n a t u r e o f th e l o n g r a n g e fo r c e . T h i s d i s t o r t i o n is

s m a l l f o r s m a l l v a l u e s of t o t a l a n g u l a r m o m e n t u m J, a n d f o r

l a r g e v a l u e s o f s i n g l e - p a r t i c l e a n g u l a r m o m e n t u m /.

(v-c) P a r t i c l e - h o l e a d m i x t u r e s t o th e H a r t r e e - F o c k s t a t e s

o f t h e e v e n - e v e n N = Z n u c l e i o f the 26 - 1 d s h e l l a r e m i n i m a l .

(v-U) P a r t i c l e - h o l e a d m i x t u r e s a r e i n a d e q u a t e t o e x p l a i n

th e s y s t e m a t i c d i s c r e p a n c i e s b e t w e e n c a l c u l a t e d a n d e x p e r i ­

m e n t a l s p e c t r a .

(v-Lt-i) P a r t i c l e - h o l e s t a t e s a r e o f us e i n e x p l a i n i n g the

n a t u r e o f e x c i t e d s t a t e s o f th e e v e n - e v e n N = Z n u c l e i o f the

26 - 1 d s h e l l , b u t n u m e r i c a l a g r e e m e n t w i t h e x p e r i m e n t a l l y

o b s e r v e d e i g e n v a l u e s o f th e H a m i l t o n i a n ar e n o t o b t a i n e d .

(-ox) I n d i c a t i o n s ar e t h a t H a r t r e e - F o c k d o e s r e p r e s e n t

a g o o d a p p r o x i m a t i o n to th e m o r e r e a l i s t i c m a n y - b o d y p r o b l e m

i n t h e r e g i o n 0 " ^ - C a ^ . H o w e v e r , th e e x p l a n a t i o n o f l o w -

l y i n g s p e c t r a h a s b e e n s e e n to lie, n o t w i t h a s i n g l e d e f o r m e d

s t a t e (e.g., th e HF s t a t e ) , b u t r a t h e r w i t h a n i n t e r a c t i o n

a m o n g the f e w l o c a l m i n i m a o f th e c o m p l i c a t e d H F e n e r g y s u r ­

f a c e .

(x) It is s u g g e s t e d t h a t th e m e t h o d o f p r o j e c t i n g a n g u ­

l a r m o m e n t u m s t a t e s b e f o r e th e HF v a r i a t i o n o f w a v e f u n c t i o n s

b e e m p l o y e d , r a t h e r t h a n t h a t of p r o j e c t i o n a f t e r v a r i a t i o n .

133

Page 203: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T h i s s h o u l d p r o v e u s e f u l i n o b v i a t i n g i n t e r a c t i o n c a l c u ­

l a t i o n s a m o n g the l o w - l y i n g d e f o r m e d H F s o l u t i o n s d i s c u s s e d

a b o v e .

M i c r o s c o p i c c a l c u l a t i o n s h a v e s h o w n t h a t s y s t e m s o f

n u c l e o n s m a y u n d e r g o b e h a v i o r u s u a l l y d e s c r i b e d b y c o l l e c t i v e

p a r a m e t e r s . T h e p a r t i c l e d e g r e e s of f r e e d o m t h e n f i n d n a t u r a l

g r o u p i n g s in c o l l e c t i v e c o o r d i n a t e s . T h u s , w e h a v e a c c o m ­

p l i s h e d th e a i m of t h is w o r k i n s h o w i n g t h a t the d e t a i l e d

o r i g i n of c o l l e c t i v e b e h a v i o r i n n u c l e i m a y be u n d e r s t o o d

f r o m f u n d a m e n t a l m i c r o s c o p i c m a n y - b o d y t h e o r y .

134

Page 204: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

135

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2. I. T a l m i , R e v. M o d . P h y s . 34 70 4 (1962).

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4. T . T . S . K u o & G.E. B r o w n , Nucl. Phys . 85 40 (1966).

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C.W. W o n g , Nu c l . P h y s . A £ 1 399 (1967).

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8. J. R a i n w a t e r , Ph y s . Rev. 79. 43 2 (1950).

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140

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A P P E N D I X A - I

M A T H E M A T I C A L F O O T N O T E S

T h e a v e r a g e s h a p e of the s h e l l m o d e l p o t e n t i a l is

g e n e r a l l y c o n s i d e r e d to lie b e t w e e n t h a t of a n h a r m o n i c

o s c i l l a t o r p o t e n t i a l a n d a s q u a r e w e l l w i t h a tail. T h e

u s e o f t h e m a t h e m a t i c a l l y c o n v e n i e n t h a r m o n i c o s c i l l a t o r

l e a d s to a set of p a r t i a l l y d e g e n e r a t e s i n g l e - p a r t i c l e e n e r g y

l e v e l s . T h e m i x i n g of t h e s e l e v e l s is e x p e c t e d to p l a y a

p h y s i c a l l y i m p o r t a n t r o l e i n t h e p r o p e r d e s c r i p t i o n o f li g h t

n u c l e i . T h e g r o u p o f t h r e e d i m e n s i o n a l u n i t a r y t r a n s ­

f o r m a t i o n s m a y b e u s e d to c l a s s i f y th e s t a t e s of p a r t i c l e s

i n an y of t h e s e d e g e n e r a t e o s c i l l a t o r c o n f i g u r a t i o n s . 33 T h i s

m a y b e s e e n to be a c o n s e q u e n c e of th e s y m m e t r y o f th e h a r ­

m o n i c o s c i l l a t o r H a m i l t o n i a n

H q = n. 2 + b V (A - I - l )

w h i c h is i n v a r i a n t , no t o n l y w i t h r e s p e c t to r o t a t i o n s , b u t

a l s o w i t h r e s p e c t to t h e g r o u p d e s c r i b e d b y th e n i n e o p e r ­

a t o r s

H Q = f i 2 + b “ p 2

L y = ( t x p ) y U - I - 2 )

Q y = / W ^ [ / L ?y'2 (e/t, ^ ) + b 4p 2yJ(0p ,4>p )]/b2J

T h e L y ar e the t h r e e i n f i n i t e s i m a l r o t a t i o n o p e r a t o r s i n c o o r ­

d i n a t e s p a c e , a n d the Q y a r e th e f i v e c o m p o n e n t s o f a s e c o n d

r a n k t e n s o r o p e r a t o r r e l a t e d t o the o p e r a t o r s of i n f i n i t e s i m a l

141

1 . The Group

Page 211: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

142

q u a d r u p o l e d i s t o r t i o n s . T h e i n v a r i a n c e of H q w i t h r e s p e c t

to t h e g r o u p is e q u i v a l e n t to t h e c o m m u t i n g of H q w i t h

t h e o p e r a t o r s (A-I -2 ) of t h e ' g r o u p . 79 T h e d e g e n e r a t e l e v e l s

b e l o n g to th e s a m e i r r e d u c i b l e r e p r e s e n t a t i o n of U^, i.e.,

the o p e r a t o r s (A-I-2) a r e th e n i n e p r o d u c t s of th e t h r e e

o s c i l l a t o r c r e a t i o n o p e r a t o r s ( t - i b 2p) a n d th e t h r e e d e ­

s t r u c t i o n o p e r a t o r s (£ + i b 2p). C l e a r l y , t h e s e p r o d u c t

o p e r a t o r s m u s t l e a v e th e e n e r g y u n c h a n g e d .

22. C a l c u l a t i o n o f < j m |Y q |j m >

T h e d i a g o n a l m a t r i x e l e m e n t s of th e s p h e r i c a l h a r m o n i c2

V q a r e c a l c u l a t e d in th e s h e l l m o d e l b a s i s |jm>. T h e b a s i s

m u s t b e s e p a r a t e d i n t o its o r b i t a l a n g u l a r m o m e n t u m | a n d

1 / 2s p i n |xm > c o m p o n e n t s s i n c e th e s p h e r i c a l h a r m o n i c a f f e c t s £

o n l y t h e o r b i t a l p a r t of th e w a v e f u n c t i o n :

9 j + 1 / 2 i x i 2< j m \ V 0 \ j m > s I I I C ( l 1 , 1 / 2 , j ; m 1 , m - m 1 ) C ( l z , 1 / 2 , j ; m 2 , m - m z )

h l z s mi- m z - j - 1 / 2 -I x - l z

( A -I -3)

2T h e r e d u c e d m a t r i x e l e m e n t s o f V a r e w e l l k n o w n , b e i n g g i v e n

b y 261/2

<l^ \ \Yl \ 11 ^ > = C [lv l , 1 ^ 0 , 0 )4-n ( 2 1 ^ + 1 )

In o r d e r t h a t th e CG c o e f f i c i e n t C U ,2,£ ;0,0) n o t v a n i s h ,

L l + L ^ + 2 m u s t b e even. W i t h t h e r a n g e o f s u m m a t i o n s d e f i n e d in

e q u a t i o n (A-I*3 ) a b o v e , o n l y t h e t e r m s h a v i n g ^ j = -^2 a n d m j ~ m 2

c o n t r i b u t e to th e sum:

Page 212: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

< j m \ v U j m > I C ( l , 2 , l ; 0 , 0 ) I C ( 1 , 1 / 2 , j ; m ' , m - m ’)4 tt I = m ' = - £

y-i/2

C [ l , 1 / 2 , j ; m ’ , m - m ’ )C ( £ , 2 , £ ;m 1 , 0 ) .

I n t e r c h a n g i n g s o m e of th e i n d i c e s b y i n v o k i n g s y m m e t r y r e l a t i o n s

of t h e CG c o e f f i c i e n t s 26

143

C { Z t Z , 2; m' , - m' ) .

S u m m a t i o n o v e r th e ( a r t i f i c i a l ) i n d e x m' of th e CG c o e f f i c i e n t s

m a y b e r e p l a c e d by th e p r o d u c t of a R a c a h c o e f f i c i e n t a n d

a n o t h e r CG c o e f f i c i e n t by the i d e n t i t y 26

[ (2e+7) (Z£+1) ] i / *W (abed; etfJC (a, rf,c;a,e+<5)

= ][C{a,b,e.;a,B)C(e.,d,c;a+B,6)C(b,df6 ; 8 , 6 ) ,3

w h i c h g i v e s t h e d e s i r e d r e s u l t :

2 t - s t ]t 2 £ + y - * / 2......< y m | V J y m > = /— C [ j , 2 , j ; m , 0 ) / 2 j + 1 £ (-7) / 2 Z + T

U 4 l - j - 1 / 2

C U , 2 , l j 0 , 0 ) \ H j l j l ; 1 / 2 , 2 ) . (A-I -4)

U s i n g a r e l a t i o n g i v e n b y B r i n k a n d S a t c h l e r 80 f o r t h e s p e c i a l

3/ c o e f f i c i e n t

( - 1 / 2 7/2 fl) = -C(2a+/)(2b+I)]i/2W(abcd;e7/2)C(abe;O0)

a + b + e = e v e n

< J m I I j m > - /— C ( j , 2 , j ; m , 0) C (/, 2, /; - 1 / 2 , 0 ) , u 4

w h e r e it ha s b e e n a s s u m e d t h a t o n l y on e £ - v a l u e is a l l o w e d in

Page 213: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

144

t h e s u m m a t i o n . U t i l i z i n g t h e c l o s e d e x p r e s s i o n g i v e n b y

A b r a m o w i t z 81 f o r the s e c o n d CG c o e f f i c i e n t a b o v e , o b t a i n s1 / 2

<y 11v2 i|j> 5 [ 2/r 7) ( 2 j ' + 3 )

6 4 k j l j + 1 )(A-I-5)

Page 214: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

A P P E N D I X A - I I C O L L E C T I V E N U C L E O N M O T I O N S

T h e t h e o r y of n u c l e o n s m o v i n g i n a d e f o r m e d f i e l d w a s

d e v e l o p e d 1 3 " 15 in the 19 50 s f o l l o w i n g s u g g e s t i o n s b y

R a i n w a t e r 8 . T h e s u m m a r y b e l o w c l o s e l y f o l l o w s t h e s e w o r k s ,

a n d i n n o w a y d o w e i n t e n d it t o b e c o m p l e t e .

A n o n s p h e r i c a l s u r f a c e R m a y b e d e s c r i b e d b y its

e x p a n s i o n i n s p h e r i c a l h a r m o n i c s

1 . The N u c le a r S u r fa c e

w h e r e R q is th e e q u i l i b r i u m s p h e r i c a l r a d i u s ; the e x p a n s i o n

d e f o r m a t i o n o f t h e n u c l e a r s u r f a c e . If t h e d e v i a t i o n s

f r o m s p h e r i c i t y ar e to c o n s e r v e the n u c l e a r v o l u m e , t h e n R Q

m u s t b e r e p l a c e d b y t h e e x p r e s s i o n

o s c i l l a t i o n s p r e d i c t s t h e p o t e n t i a l e n e r g y o f d e f o r m a t i o n to

b e o f t h e f o r m

R(6,4>) = R q (1+X , y

c o e f f i c i e n t s are g e n e r a l i z e d c o o r d i n a t e s d e s c r i b i n g th e

* x-1/3 ( A - I I - l a )

A s s u m i n g th e c o e f f i c i e n t s a r e s m a l l , th e t h e o r y o f s m a l l

V d e f = 2 ^ C x J a x J 2( A - I I - 2 )

a n d th e a s s o c i a t e d k i n e t i c e n e r g y

Page 215: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

w h e r e a n d m a y b e d e v e l o p e d f r o m a s s u m p t i o n s c o n c e r n i n g

t h e n a t u r e of n u c l e a r m a t t e r . B r i e f l y , f o r i r r o t a t i o n a l f l o w

o f a c o n s t a n t d e n s i t y f l u i d u n d e r s u r f a c e t e n s i o n a l o n e

146

C x = S R 0 2 ( X - l ) U + 2 ) ,

w h e r e p is t h e m a s s d e n s i t y a n d S th e s u r f a c e t e n s i o n .

T h e L a g r a n g i a n L = T - V is t h u s a s u m o f s e p a r a t e t e r m s

f o r e a c h of th e g e n e r a l i z e d c o o r d i n a t e s a X y> a n d e a c h o f t h e s e

is t h e L a g r a n g i a n o f a s i m p l e h a r m o n i c o s c i l l a t o r . T h e o s c i l ­

l a t o r f r e q u e n c y a s s o c i a t e d w i t h th e v a r i a b l e is

B,

or, w i t h th e a b o v e r e s u l t s

U A =S A (A - l ) ( A + 2 )

PR,

1/2( A - I I - 4 )

S i n c e d e f o r m e d n u c l e a r s u r f a c e s a r e k n o w n to h a v e d o m i n a n t +

A = 2 c o m p o n e n t s , h i g h e r o r d e r d e f o r m a t i o n s w i l l n o t b e c o n s i d e r e d

i n t h i s p r e s e n t a t i o n .

W e c o n s i d e r the t r a n s f o r m a t i o n f r o m a f i x e d f r a m e of

r e f e r e n c e to th e b o d y c o o r d i n a t e s y s t e m w h i c h c o i n c i d e s w i t h

t h e p r i n c i p a l a x e s of th e e l l i p s o i d a l s u r f a c e . U n d e r this

t r a n s f o r m a t i o n th e g e n e r a l i z e d c o o r d i n a t e s a 2p d e s c r i b i n g the

d e f o r m a t i o n a r e g i v e n i n the b o d y f r a m e b y a v , w h e r e

fT y p i c a l r a t i o s of h e x a d e c u p o l e / q u a d r u p o l e a m p l i t u d e s m a y

b e o f th e o r d e r 2 0 % 1 9 .

Page 216: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

147

( A - I I - 5 )

s e c t i o n I I . 2.

T h e m o d e l e m p l o y e d h e r e w i l l a s s u m e a x i a l s y m m e t r y .

T h e r e ha s b e e n s o m e e v i d e n c e as o f l a te t h a t c o n s i d e r a t i o n

s h o u l d be g i v e n to t r i a x i a l s h a p e s . T h e s e h o w e v e r , a r e

g e n e r a l l y o b t a i n e d b y f i t t i n g e x p e r i m e n t a l d a t a w i t h p a r a m ­

eters,. T h e t r i a x i a l f i t s , h a v i n g a n o t h e r f r e e p a r a m e t e r ,

a r e e x p e c t e d to g i v e b e t t e r a g r e e m e n t w i t h t h e da ta . T h is

d o e s n o t, t h e r e f o r e , i n d i c a t e t h e v a l i d i t y o f t h e a s s u m p t i o n

I n a n y c a s e , th e i n t e n t h e r e is to s t a y w i t h i n th e f r a m e w o r k

of s i m p l e m o d e l s .

F o r a n e l l i p s o i d of r e f o l u t i o n a 2= a _ 2 , a n d a ^ = a _ ^ = 0 .

D e f i n i n g t h e n e w p a r a m e t e r s g a n d y by

3, t h e r e f o r e , p a r a m e t e r i z e s th e t o t a l d e f o r m a t i o n of th e

n u c l e u s . T h e c o o r d i n a t e y is a s h a p e p a r a m e t e r w h i c h

d e s c r i b e s th e d e v i a t i o n f r o m r o t a t i o n a l s y m m e t r y . G e n e r a l l y

t h e i n c r e m e n t s o f t h e t h r e e a x e s o f the e l l i p s o i d f o r a

d e f o r m a t i o n (3,y) a r e g i v e n by

a Q = 3c o s y( A - I I - 6 )

a ~ = a o = — 3s i n Y 2 - 2 / 2

it m a y e a s i l y be v e r i f i e d t h a t

6R, = / 5 gR c o s C y - ^ ) 1 ETT ° J i = l , 2 , 3 .

Page 217: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T h e r e f o r e , f o r a n e l l i p s o i d o f r e v o l u t i o n , Y = 0 a n d Y=ff

c o r r e s p o n d to p r o l a t e a n d o b l a t e d e f o r m a t i o n s , r e s p e c t i v e l y .

T h e p o t e n t i a l e n e r g y of d e f o r m a t i o n ( A -I I-2) in

th e b o d y s y s t e m n o w t a k e s the f o r m

V d e f = | c ® 2 • ( A - I I - 2 a )

T r a n s f o r m i n g the k i n e t i c e n e r g y t o th e b o d y f r a m e of

r e f e r e n c e l e a d s to a n a t u r a l s e p a r a t i o n i n t o a v i b r a t i o n a l

t e r m — b y w h i c h th e e l l i p s o i d a l s h a p e v a r i e s — a n d a r o t a t i o n a l

t e r m — b y w h i c h th e s h a p e is m a i n t a i n e d w h i l e th e e l l i p s o i d

r o t a t e s . T h e v i b r a t i o n a l e n e r g y m a y b e e x p r e s s e d as

T v i b = | b I I I * - | ( « 2 + • (A -I I- 7)

T h e r o t a t i o n a l t e r m m a y be e x p r e s s e d i n a m a n n e r c o m p l e t e l y

a n a l o g o u s t o t h a t o f a r o t a t i n g e l l i p s o i d i n c l a s s i c a l

m e c h a n i c s :

T r o t " 7 I < L (A- I I ‘ 8)

w h e r e a r e the c o m p o n e n t s o f a n g u l a r v e l o c i t y of the

e l l i p s o i d a l o n g its p r i n c i p a l ax e s . I a r e th e m o m e n t '

o f i n e r t i a c o m p o n e n t s w h i c h ar e p r o p o r t i o n a l to the s q u a r e

o f th e d e f o r m a t i o n p a r a m e t e r 8:

I0 = 4 B 8 2s i n 2 (Y - ^ £ ) . (A -I I - 9 )

2. C o u p l i n g to the N u c l e a r S u r f a c e

S o m e n u c l e i m a y b e c o n s i d e r e d to b e h a v e as if t h e r e

148

Page 218: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

w e r e i n d i v i d u a l n u c l e o n s o u t s i d e of a r e l a t i v e l y i n e r t

d e f o r m e d co re , s u c h as d e s c r i b e d a b o v e. If t h e r e w e r e

n o c o u p l i n g at a l l b e t w e e n th e c o r e a n d e x t e r n a l n u c l e o n s ,

t h e c o r e w o u l d u n d e r g o r o t a t i o n s a n d s u r f a c e o s c i l l a t i o n s

i n d e p e n d e n t of p a r t i c l e e x c i t a t i o n s o f th e o u t e r n u c l e o n s .

A d e g r e e o f c o u p l i n g is a l w a y s i n t r o d u c e d h o w e v e r , b y the

c o n s e r v a t i o n of t o t a l a n g u l a r m o m e n t u m of the s y s t e m .

A d d i t i o n a l c o u p l i n g m a y b e i n t r o d u c e d b y c o n s i d e r i n g th e

i n t e r a c t i o n o f th e e x t e r n a l p a r t i c l e w i t h the q u a d r u p o l e

f i e l d o f th e core.

T h e d i s c u s s i o n w h i c h f o l l o w s w i l l b e l i m i t e d t o a

c o n s i d e r a t i o n of a s i n g l e n u c l e o n o u t s i d e of a core. It

m a y , a n d l a t e r w i l l , b e g e n e r a l i z e d to a c o n s i d e r a t i o n of

s e v e r a l e x t e r n a l n u c l e o n s .

T h e t o t a l a n g u l a r m o m e n t u m it of t h e n u c l e u s m a y b e

s e p a r a t e d i n t o c o n t r i b u t i o n s f r o m th e a n g u l a r m o m e n t u m of

t h e c o r e (§, a n d f r o m the e x t e r n a l n u c l e o n -J (cf. F i g u r e 24).

T h e p r o j e c t i o n s of J a n d f a l o n g the b o d y z - a x i s (z') ar e

d e n o t e d b y ft a n d K, r e s p e c t i v e l y , a n d o f it a l o n g th e s p a c e

f i x e d z - a x i s by M. T h e c o m m u t a t i o n r u l e s f o r th e c o m p o n e n t s

o f 1 a n d J a l o n g th e a x e s of t h e n u c l e u s are

V b - V a ■ - 1 I a * b

* V b ” " V a " ^ a x b

V b - V a = °-T h e r o t a t i o n a l e n e r g y (A - I I - 8 ) m a y n o w b e w r i t t e n as

Page 219: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Trot ’ I J 7 (W * •° 2 I o

F o r a n a x i a l l y s y m m e t r i c c o r e Q c a n n o t h a v e a c o m -

p o n e n t a l o n g the b o d y z - a x i s ; r o t a t i o n s ar e I n d i s t i n g u i s h ­

a b l e i n th e p l a n e p e r p i n d i c u l a r to th e s y m m e t r y a x i ~ . In

t h i s c a s e K=ft a n d the d i r e c t i o n o f i n F i g u r e 24 is p e r ­

p i n d i c u l a r to the z ' - a x i s . F o r a n a x i a l l y s y m m e t r i c s u r ­

f a c e d e f o r m a t i o n I j = I 2=I T h e r o t a t i o n a l e n e r g y m a y n o w

b e e x p a n d e d as

150

E l i m i n a t i n g Q o b t a in s

w h i c h , a f t e r s o me m a n i p u l a t i o n b e c o m e s

T ro t = — 2 [ I ( I + l ) + j ( j + l ) - K 2-ft2 ] + — 2 (K-ft)2 r0t 21 2 1 3

- — ( I . J + 1 1 ) . ( A -I I- 1 0 )21 “ +

T h e l a s t t e r m , w h i c h c o u p l e s the t o t a l a n g u l a r m o m e n t u m w i t h

w i t h t h a t of the e x t e r n a l n u l c e o n is g e n e r a l l y r e f e r r e d to

as th e R P C t e r m 8 2 . T h i s h o w e v e r , is a m i s n o m e r , s i n c e

t h e c o u p l i n g I n t r o d u c e d b y th e i n c l u s i o n of t h i s t e r m is

b e t w e e n t h e t o t a l a n g u l a r m o m e n t u m a n d t h a t o f th e s i n g l e

p a r t i c l e , a n d not, as t h e n a m e i m p l i e s , b e t w e e n th e r o t a ­

t i o n a l m o t i o n of th e c o r e a n d th e s i n g l e - p a r t i c l e a n g u l a r

m o m e n t u m . B e c a u s e of t h e a p p e a r a n c e of th e r a i s i n g a n d

l o w e r i n g o p e r a t o r s , it g i v e s r i s e to b a n d m i x i n g f o r AK =± 1.

If t h i s m i x i n g is s m a l l , as f o r s t r o n g l y d e f o r m e d n u c l e i ,

K m a y b e r e t a i n e d as a n a p p r o x i m a t e q u a n t u m n u m b e r .

Page 220: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

F i g u r e 24. T h e t o t a l a n g u l a r m o m e n t u m 1 of a n o n - s p h e r i c a l

n u c l e u s Is t h e r e s u l t a n t o f th e p a r t i c l e a n g u l a r m o m e n t u m J

a n d the c o r e a n g u l a r m o m e n t u m (§. T h e p r o j e c t i o n s o f J a n d f

a l o n g th e z - a x i s ( z 1 ) o f th e n u c l e u s , a r e ft a n d K, r e s p e c -

t i g v e l y . T h e p r o j e c t i o n of 1 o n t o the s p a c e - f i x e d z - a x i s

is M. If t h e n u c l e a r s u r f a c e is a x i a l l y s y m m e t r i c , $

c a n n o t h a v e a c o m p o n e n t a l o n g t h a t a x i s , s i n c e q u a n t u m

m e c h a n i c a l r o t a t i o n s a b o u t a s y m m e t r y a x i s a r e u n o b s e r v a b l e .

I n t h a t c a s e w i l l be p e r p i n d i c u l a r to th e z ' - a x i s .

Page 221: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

G

K

/

Page 222: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

151

T h e t o t a l H a m i l t o n i a n of th e s y s t e m m a y n o w b e

w r i t t e n as the s u m o f th e n u c l e a r s u r f a c e H a m i l t o n i a n , the

p a r t i c l e H a m i l t o n i a n , a n d a n i n t e r a c t i o n term:

H ■ " s u r f + Hp a r t + H ln t • U - U - l l )

T h e s u r f a c e t e r m Is g i v e n b y e q u a t i o n s ( A - I I - 2 a , 7 , 1 0 ) :

H s u r f = T vi b + T r o t + V d e f . ( A -I I - 1 2 )

T h e p a r t i c l e ( s h e l l m o d e l ) H a m i l t o n i a n is s e p a r a b l e i n t o

a k i n e t i c e n e r g y te rm , a c e n t r a l p o t e n t i a l e n e r g y te rm ,

a n d a s p i n - o r b i t term:

H p a r t ■ T p a r t + V p a r t (r) + V 5oJ 'a ( A - I I - 1 3 )

w h e r e V gQ is a s t r e n g t h p a r a m e t e r . R j_n b r e p r e s e n t s th e

i n t e r a c t i o n o f t h e p a r t i c l e w i t h th e n u c l e a r q u a d r u p o l e

s u r f a c e d e f o r m a t i o n , a n d m a y b e w r i t t e n i n the f o r m

H m t = (a - i i - i H)

w h e r e k ( r ) is a d e n s i t y d e p e n d e n t s t r e n g t h f u n c t i o n . T h e

e x p e c t a t i o n v a l u e s of H i n t d e p e n d o n the p a r t i c l e s t a t e i n

q u e s t i o n , a n d its o r i e n t a t i o n r e l a t i v e to the d e f o r m e d s u r ­

f a c e i n t h e l a b o r a t o r y f r a m e . T h e c o o r d i n a t e s a ^ y i n the

l a b o r a t o r y f r a m e a r e r e l a t e d to t h o s e i n th e b o d y f i x e d

f r a m e b y t h e t r a n s f o r m a t i o n e q u a t i o n ( A - I I - 5 ) , y i e l d i n g

Hint ’ ®5vav ^ < e **)Sy v ^

the t r a n s f o r m a t i o n of th e s p h e r i c a l h a r m o n i c to th e b o d y -

f i x e d c o o r d i n a t e f r a m e is g i v e n b y

Page 223: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

y M

T h e r e f o r e , the I n t e r a c t i o n H a m i l t o n i a n i n the b o d y s y s t e m

is g i v e n b y

H i n t = - k ( r ) J a / J C e ' , * ' ) . ( A - I I - l 4 a )

T h e w a v e f u n c t i o n f o r t h e s y s t e m c a n b e w r i t t e n as th e

p r o d u c t of a f u n c t i o n d e s c r i b i n g t h e r o t a t i o n a l m o t i o n a n d

a p a r t i c l e f u n c t i o n '

152

t M K «21+1

1/2 v m * l . (A-it-15)8tt2

F o r m u l a t i n g the e x p e c t a t i o n v a l u e of H i n t :

. / • 2 T Bc0SYk(r) BOj-Ji l t l l - (A -II-1 6 ) 64ir j ( J + l )

F o r a n o b l a t e d e f o r m a t i o n ( y = ir ), th e l o w e s t s t a t e

is s e e n to h a v e Q=j . F u r t h e r d i s c u s s i o n c o n c e r n i n g t h e

p r e d i c t i o n s o f t h i s m o d e l ar e m a d e i n C h a p t e r III.

Page 224: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

A P P E N D I X B-I

( j ) n C O M P U T E R C O D E

T h i s c o d e w a s d e s i g n e d f o r u s e o n th e C o n t r o l D a t a C o r ­

p o r a t i o n 6 6 00 at th e A t o m i c E n e r g y C o m m i s s i o n C o m p u t e r C e n t e r ,

N e w Y o r k U n i v e r s i t y C o u r a n t I n s t i t u t e o f M a t h e m a t i c s . T h e

r e q u i r e d i n p u t is in th e f o l l o w i n g form:

(a) J T W , N N 1 , N N 2 - t w i c e the p a r t i c l e a n g u l a r m o m e n t u m

(JTW), the n u m b e r of p a r t i c l e s f o r the f i r s t p r o b l e m (NN1),

a n d th e n u m b e r o f p a r t i c l e s f o r th e l a s t p r o b l e m (NN2), a p p e a r i n g

i n (313) f o r m a t .

(b) N J - th e m u l t i p l i c i t y o f J - s t a t e s f o r the f i r s t ( / ) W

c o n f i g u r a t i o n .

(c) N J - th e m u l t i p l i c i t y o f J - s t a t e s f o r the s e c o n d

( / ) n c o n f i g u r a t i o n .

(d) etc.

P r o c e s s i n g p r o c e e d s as f o l l o w s :

(a) D a t a is r e a d in.

(b) P R E L I M is ca l l e d . It c a l c u l a t e s a f e w a r r a y s , i n ­

c l u d i n g th e t r i a n g u l a r a r r a y u s e d f o r c o n v e r t i n g M - a m p l i t u d e s

to J - a m p l i t u d e s .

(c) P R E P N D g e n e r a t e s the l i s t of a l l S l a t e r d e t e r m i n a n t

s t a t e s in th e ( / ) n c o n f i g u r a t i o n w i t h M^O.

(d) HOP, th e H a m i l t o n i a n o p e r a t o r , s c a t t e r s e a c h of the

i n t r i n s i c s t a t e s , th e m a t r i x e l e m e n t s b e i n g e v a l u e a t e d in

F U N C T I O N V.

153

1 . P r o j e c t i o n Code

Page 225: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

(e) J P L U S o p e r a t e s o n e a c h of the i n t r i n s i c s t a t e s , a n d

a l s o o n t h o s e s t a t e s s c a t t e r e d to b y th e H a m i l t o n i a n .

(f) S C H M I T f o r m s a l l r e q u i r e d o v e r l a p s , s o l v e s f o r th e

m e t r i c s f o r e a c h v a l u e of th e t o t a l a n g u l a r m o m e n t u m , a n d

f i n d s th e m a t r i c e s w h i c h w i l l o r t h o n o r m a l i z e t h e s e m e t r i c s .

(g) S T P T W O f o r m s a l l H a m i l t o n i a n o v e r l a p s a n d a p p l i e s

t h e o r t h o n o r m a l i z a t i o n m a t r i c e s f o r e a c h a n g u l a r m o m e n t u m v a l u e .

T h e s e a r e t h e n o u t p u t f o r . t h e a n a l y s i s code.

(h) S t e p s (d), (f), a n d (g) a r e r e p e a t e d f o r e a c h v a l u e

o f th e t w o - b o d y a n g u l a r m o m e n t u m a l l o w e d by v e c t o r c o u p l i n g

a n d the P a u l i p r i n c i p l e . In t h is w a y the H a m i l t o n i a n is

c o m p l e t e l y p a r a m e r t e r i z e d by its t w o - b o d y i n t e r a c t i o n s . It

m a y t h e n b e s u p p l i e d i n the a n a l y s i s c o d e w h i c h f o l l o w s .

154

Page 226: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

D I M E N S I O N N C M A X ( 3 5 ) . C O ( 6 7 0 0 1 , C K 6 7 0 0 1 » S Q M ( 2 0 1 . C O E D ( 3 5 . 3 5 ) , N U ( 3 5 ) . 1 K U K ( 8 ) , N O O ( 6 7 0 0 > , I N D ( 7 0 > , M S < 1 0 ) , C O V I 3 5 ) , S ( 1 0 ) , N J ( 3 5 )

0 1 M E N S I ON N T R N S C I S 3 0 ) , N T R E F L ( S 3 0 >D I M E N S I O N 7 ( 1 0 1COMMON N N N , J F C R C E , N U M B E RC C M M . O N / D L K I / T J P O , J T W , N U M J , L N G T 0 T , N N N M 1 , N S P S » N S P S P 1 . J M A X V , J M A X M O ,

1 L E N G T H , L N C i n , J M L T M X , N N N P l , J T W 1 2 C O M M O N / B L K 2 / C O . C l , S O M . C O E D , C O V , N C M A X , N U . K U K . N O O , I N O . H S ,

1 S . N JC O M M O N / B L K 3 / F j l , F N N C O M M O N / B L K 6 / K E R R S ( 7 ) . N O O R U HD O U B L E P R E C I S I O N C O , C 1 , C , S Q M , C O E D , C O V , S O O , F K G . T E M A , T E M E • T J P OD O U B L E P R E C I S I O N F J I , TV, J . C O U N T D O U B L E P R E C I S I O N F NN D O U B L E P R E C I S I O N B I C O O O U B L E P R E C I S I O N R l , R L M I , R N S T , R N S T P l D O U B L E P R E C I S I O N B C u N T

J T W I S T W I C E T HE J OF E A C H P A R T I C L E ------- NNN I S T H E N U M B E R O FP A R T I C L E S J M A X V I S T H E N U M B E R O F D I F F E R E N T T O T A L ‘ J * V A L U E SP O S S I B L E - - - N J I S T H E N U M B E R O F S T A T E S W I T H A G I V E N ' J * V A L U E -------L E N G T H I S T HE T O T A L N U M B E R OF S T A T E S F OR T H E NNN P A R T I C L E S ( W I T H NON­N E G A T I V E T O T A L ' M M N U MJ I S T H E N U M B E R O F S T A T E S W I T H A T O T A LV A L U E OF Z E R O , I F T H E R E A R E AN E V E N N U M B E R O F P A R T I C L E S , OR A T O T A L ' H *V A L U E OF 1 / 2 I F T H E R E A R E AN ODD N U M B E R OF P A R T I C L E S ------ J M L T M X I S T H EM A X I M U M J - M U L T I P L I C I T Y O F S T A T E S

CO 1 1 - 1 , 7 1 K E R R S t 1 1 = 0

R E A D I S , 1 0 0 0 ) J T W , N N N 1 , N N N 2 1 0 0 0 F OR MA T ( 3 I 3 )

N S P S - J T W * 1 N S P S P l = N S P S * l J T W I 2 - N S P S / 2 T J P O = N S P S

DO SOOO N N N - N N N l , N N N 2 W R I T E ( 6 , 4 0 0 ) N N N , J T W

4 0 0 F 0 R M A T ( l H l , I 2 t I X . 2 3 H P A R T I C L E S R E S T R I C T E D T 0 . I 3 . 8 H / 2 S H E L L )N N N P 1 - N N N * 1 N N N H l - N N N - l F N N - N N NJ M A X V - ( N N N * J T W - N N N * N N N M l * 2 ) / 2 J M A X M O - J M A X V —IR E A D ( 5 , 7 0 4 ) ( N J I I ) , I » 1 , J M A X V )

7 0 4 F OR MA T ( 2 4 1 3 )W R I T E 1 6 , 4 0 1 ) ( N J I I ) , 1 = 1 , J M A X V )

4 0 1 F O R M A T ( 6 H N J 1 I ) • , 3 X , 1 7 1 4 / 1 9 X , 1 7 1 4 / ) )

4 0 3 L E N G T H = 0N U M J - 0 . ‘NCMAX ( J M A X V * 1 ) - 0j m l t m x - o

0 0 1 0 1 = 1 . J M A X V I L - J M A X V - I * 1N C M A X I L L ) - N C M A X ( 1 1 * 1 ) * N J I L L )L E N G T H - l E N G T H + N C H A X ( L L )J M L T M X - M A X O I J M L T M X , N J I I ) )

1 0 N U M J - N U M J . N J ( I )L 0 N G - 2 * l E MGT H

noon

N U M B E R - J M L T M X 4 J M L T M X / 2 L N G T O T - B I C O I T J F 0 » F N N ) - . 9 L N G T T 1 - L N G T 0 T T W J - J T W F J 1 - T W J / 2 . D 0

C A L L P R E L I M

C A L L P R E P N D

M N - 10 0 l i I - l . N U M J N T R N S C ( I ) = 0

1 1 N T R E F L ( I ) - 00 0 8 1 N S T - l . N U M J

C T H E S T A T E S A R E T E S T E D F O R T H E C R I T E R I A D I S C U S S E D B E L O W

1 2 4 C A L L C 0 D 2 L ( K U K , N O O ( N S T ) , N N N )

0 0 4 3 I - l . N N N R K U K - K U K ( I )

4 3 S < l l - R K U K - l . - F J l M M M - N N N / 21 F I M N . E Q . D G 0 T O 1 0 0

C T H E S T A T E I S T E S T E D T O S E E I F I T I S A R E F L E C T I O N O F A N Y O F T H E .C P R E V I O U S I N T R I N S I C S T A T E S . I F I T I S I T I S P L A C E D I N T H E A R R A Y N T R E F l

N M - M N - 1 DO 5 6 1 = 1 , NM K - N T R N S C I I )C A L L C 0 D 2 L ( M S , N O O ( K ) , N N N )0 0 5 7 J - l . N N N R M S - M S I J )

5 7 T < J I - R M S - l . - F J l DO 5 8 J - l . M M M L L - N N N P 1 - JI F ( S ( J ) * T ( L L ) » G T . 0 . 1 ) G 0 T O 5 6 ( F ( T ( J ) * S ( L L ) . G T . O . D G O T O 5 6

5 8 C O N T I N U E1 F I MOD 1 N N N , 2 ) . E Q . 1 • A N D . A B S ( S I M M H 4 1 ) —T ( H H M * 1 ) ) . G T . 0 . 1 ) GO T O 5 6N T R E F L I I ) - N S T GO TO 8 1

5 6 C O N T I N U E

1 0 0 I F ( M O O ( N N N , 2 ) . E O . O ) G O T O 4 9

I F T H E R E A R E AN 0 0 0 N U M B E R OF P A R T I C L E S T H E S T A T E I S T E S T E D F O R I N ­C L U S I O N OF T H E V A L U E 1 / 2 . I F I T I S I N C L U D E O T H E S T A T E I S F U R T H E R T E S T E D F O R S Y M M E T R Y A B O U T T H E V A L U E 1 / 2 . I F T H E R E A R E AN E V E N N U M B E R OF P A R T I C L E S T H E S T A T E I S T E S T E O F O R S Y M M E T R Y A B O U T 0

DO 4 6 I - l . N N N L J - I

155

Page 227: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

I F ( A 8 S ( S M ) - . 5 ) . L T . 0 . l ) G 0 T O 4 74 6 C O N T I N U E

GO TO 4 54 7 P P » N N N - 1

I F ( L J . E O . N N N ) G O T O 4 8 0 0 5 0 K = L J , P H

5 0 S I K I = S t K * 1 )GO TO 4 8

4 9 P P = N N N4 8 0 0 4 4 1 = 1 , HP H

L H = P M - I ♦ 1I F ( A B S ( S < I ) » S ( L M > > . G T . O . l > G O T O 4 5

4 4 C O N T I N U E GO TO 8 1

C t h e S T A T E I S GOOO I F J - P L U S C A N O P E R A T E H O R E T H A N O N C E

4 5 0 0 5 2 I - l , N N N M l L K « I » lI F I ( K U K ( I ) - K U K I L K ) ) . G T . 1 ) G 0 T O 5 3

5 2 C O N T I N U E GO TO 8 1

5 3 I F ( L K . E O . N N N ) G O T O 9 4 0 0 5 4 I = L K , N N N M 1I F I ( K U K ( I ) - K U K I I + 1 ) ) . G T . 1 > G 0 T O 5 5

5 4 C O N T I N U E9 4 I F I N S P S P 1 - K U K ( 1 ) . G T . 1 ) G 0 T O 5 5

GO TO 8 1

C I F A L L C R I T E R I A A R E M E T , T H E S T A T E I S P L A C E D I N T H E A R R A Y N T R N S C

5 5 N T R N S C ( H N ) - N S T M N * M N * l

8 1 C O N T I N U E M N = M N - 1

C P R O C E S S I N G B E G I N S H E R E

J F O R C E - O I N D E X - 0 N 0 0 R U P = 7 5

5 0 5 1 8 0 U N T - 1 . 0 0 C Q U N T - 1 . 0 0

5 0 5 0 C A L L K Y I 0 I 4 , 1 , 0 , 0 )R E W I N D 1 R E W I N D 2I N T E G E = J T W + 1 0 0 * N N N + 1 0 * J F O R C E !C A L L 0 1 S P L A ( 1 0 H P R Q G R E S S , I N T E G E )I C O U N T = 0I F I I N U E X . E 0 . 1 I G 0 T O 9 9 8 DO 2 5 0 5 . 1 - 1 , N U M J

2 5 0 5 C 0 ( I ) = 0 . 0 0

C A C O M B I N A T I O N OF ONE I N T R I N S I C ANO ONE N O N - I N T R I N S I C * N O N - R E F t E C T E D “C I N T R I N S I C S T A T E I S C H O S E N A S T H E S T A T E W I T H W H I C H TO W O R K . F R OM H E R E

u o u u

C ON T H E C O M B I N A T I O N I S R E F E R R E D T O A S T H E I N T R I N S I C S T A T E

J - l5 9 L - l6 0 I F ( L . G T . N U M J ) C O U N T - C O U N T * ! . 5 0 0

I F I L . G T . N U H J I L - IK = LI F ( H N . E Q . O ) GO T O 4 4 4 5 DO 1 0 0 6 M P N = l . M NI F I K . E O . N T R N S C ! M H N ) . O R . K . E Q . N T R E F L I M M N 1 1 G O T O 1 0 0 5

1 0 0 6 C O N T I N U E L = L + 1GO TO 4 4 4 4 *

1 0 0 5 l = L + lGO TO 6 0

4 4 4 4 N S T = N T R N S C ( J )R N S T = NS T R N S T P 1 = N S T * 1C 0 I N S T I = 8 0 U N T * R N S T P I / R N S T

4 4 4 5 R L = K R L M I = K + 1C O ( K ) = C 0 U N T * R L H 1 / R L

9 9 8 I C O U N T = I C O U N T + 1 .I F ! I N O E X . E O . O I G O T O 4 4 4 6 R E A D ) 1 ) ( C 0 ( I ) , I - I , L E N G T H )

4 0 0 0 C A L L HOP GO TO 7 7 7

J - P L U S O P E R A T E S ON T H E I N T R I N S I C S T A T E . T H E R E S U L T I S W R I T T E N O U T ONT A P E I

4 4 4 6 C A L L J P L U S ( C O )

I F ( I C O U N T . G E . N O O R U H ) G O T O 6 6 46 6 5 C A L L H Y 1 0 ( 4 , 2 , C O , L O N G )

I F I K E R R S i n . E Q . O I G G T O 6 6 6 0 0 2 1 = 1 , 7I F ( K E R R S ( I ) . G T . 2 ) G 0 T O 2 2 2 6

2 C O N T I N U EN O D R U H = M I N O ( I C O U N T , N O O R U H )

6 6 4 W R I T E I 2 ) ( C O ( l ) , 1 = 1 , L E N G T H )6 6 6 W R I T E ( l ) ( C O ( I ) , 1 = 1 , L E N G T H )

0 0 6 6 7 1 = 1 , N U MJ6 6 7 C 0 ( l l = 0 . 0 0

C O TO 4 4 4 7

J - P L U S O P E R A T E S ON T H E R E S U L T O F T H E H A M I L T O N I A N O P E R A T I O N ON T H E I N T R I N S I C S T A T E . T H E R E S U L T I S W R I T T E N O N T O T A P E 2

7 7 7 C A L L J P L U S ( C l )

I F I I C O U N T . L T . N O D R U M I G O TO 6 6 8 ,6 6 9 W R I T E 1 2 ) ( C l 1 1 ) . 1 - 1 . L E N G T H ) (

GO TO 4 4 4 7 j6 6 8 C A L L P Y I 0 ( 4 , 2 , C 1 , L 0 N G )

I F ( K E R R S t 1 ) . E O . O I G O T O 4 4 4 7 0 0 3 1 = 1 , 7I F ( K E R R S U ) . G T . 2 ) G 0 TO 2 2 2 6

3 C O N T I N U EN O D R U M = M I NO I I C O U N T , N O D R U M )GO TU 6 6 9

4 4 4 7 I F < I C O U N T . E Q . N U M B E R I G O TO 3 7

Page 228: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

I F ( I N D E X . E Q . 1 ( G O T C 9 9 8 I F U . E Q . M N I J « 0 I F I J . E O . Q I B O U N T * 8 0 U N T / 1 . 4 0 0 J * J * 1 C O TO 6 0

3 7 I F ( I N D E X . E Q . I ) G 0 TO 3 8 C A L L S C H H I TI NOE X * I J F O R C E * I C O TO 5 0 5 0

3 8 C A L L S T PT WO

1 0 0 2 [ F ( J F 0 R C E . E 0 . J T H 1 2 ) G 0 T O 5 0 0 0 J F O R C E * J F O R C E + 1 C O TO 5 0 5 0

5 0 0 0 W R I T E < 6 , 4 0 1 M N J ( I ) , I » l , J H A X V )

2 2 2 6 W R I T E . ! 6 , T O M K E R R S . NODRUH S T O P E N D

oo non

non

D I M E N S I O N N C M A X ( 3 5 ) , C O < 6 7 0 0 ) , C 1 ( 6 7 0 0 ) , S Q M ( 2 0 ) , C O E D ! 3 5 , 3 5 ) , N U ( 3 5 ) , I K U K ( 8 ) , N 0 0 ( 6 7 0 0 ) , I N 0 ( 7 0 ) , M S ( 1 0 ) , C O V ( 3 5 ) , S ( 1 0 ) , N J ( 3 S )

COMMON N N N . J F C R C E , N U M B E RC O M M O N / B L K 1 / T J P O , J T W , N U M J , L N G T 0 T , N N N M 1 , N S P S , N S P S P 1 . J M A X V , J M A X M O ,

1 L E N G T H , L N G T T I , J M L T M X , N N N P 1 , J T W 1 2 C O M M O N / B L K 2 / C 0 . C 1 , S Q M , C O E O , C O V , N C M A X , N U , K U K , N O O , I N O , M S ,

I S . N JD O U B L E P R E C I S I O N C O , C 1 , C , S Q M , C O E D , C O V , S O D , F K G , T E M A , T E M E , T J P O O O U B L E P R E C I S I O N F I

SUBROUTINE PRELIM

SQM I S T HE A R R A Y C F C O E F F I C I E N T S W H I C H R E S U L T F R OM O P E R A T I O N W I T H J - P L U S - N O T E T H A T WE MUST A D J U S T T H E V A L U E S O F * J * A N D » M ' W H I C H WOULD N O R M A L L Y O C C U R B E C A U S E OF OUR WAY OF C O U N T I N G

0 0 2 0 1 * 1 , N S P S F 1 * 1 .S O D = F I * I T J P O - F I I

2 0 S Q M ( I J = 0 S Q R T ( S 0 0 )

C O E D I S T H E A R R A Y OF P R O D U C T S OF T E R H S L I K E T H O S E W H I C H O C C U R I N S Q M . T H I S A R R A Y I S T H E T R I A N G U L A R C O E F F I C I E N T M A T R I X W H I C H I S U S E O TO S O L V E F O R T H E T R A N S F O R M A T I O N M A T R I X I N S T E P T W O

. N O N E * N N N - I N N N / 2 ) * 2 0 0 2 1 J * 1 , J M A X V

2 1 C O E O 1 1 , J ) * 1 . 0 0 0 0 2 2 1 * 2 , J M A X V 0 0 2 2 J * 1 . J M A X V 1 F I J . L T . D G 0 TO 2 3 F K G = ( J - I + l ) * ( J * I ~ 2 ♦ N O N E ) C O E D ! I , J ) = C O E O ( I - 1 , J ) * F K G GO 1 0 2 2

2 3 C O E O ( I , J ) = 0 . 0 02 2 C O N T I N U E

NU I S T H E L E N G T H O F T H E S U 8 V E C T 0 R U P T O ( B U T N O T I N C L U D I N G ) T H E *M» V A L U E C O R R E S P O N D I N G T O T H E I N D E X O F NU

N U 1 1 ) ° 0DO 2 0 0 0 1 * 2 , J M A X V

2 0 0 0 N U ( I ) * N U ( I - l ) + N C M A X ( t - l )

R E T U R NE N O 1

57

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uuoo

S U B R O U T I N E P R E P N ODIMENSION NCMAX135),C016700) »C 1167001, SQM1201»C0E0(35,35)»NU(351, 1KUKI8I,NOOI6700>. INDI70),MSU0),C0V(35),S<10),NJ(35)COMMON N N N . J F O R C E , N U M B E RC O M M O N / R L K 1 / T J P O , J T W , N U M J , L N G T 0 T , N N N H 1 , N S P S , N S P S P 1 » J M A X V , J M A X H 0 ,

l L E N G T H . L N G T T l , J M L T M X . N N N P l , J T W 1 2 C O M M . O N / D I K 2 / C 0 . C 1 , S O M , C O E D , C O V , N C M A X , N U , K U K , N O O . I N D . M S ,

1 S , N JD O U B L E P R E C I S I O N C O , C I . C , S Q M . C O E O , C O V , S O O , F K G , T E M A , T E M E , T J P O

THE LIST OF ALL POSSIBLE STAIES OF NNN PARTICLES WITH NON-NEGATIVE TOTAL M IS GENERATED IN NOD. THE STATE IS CHARACTERIZED BY THE H VALUES OF THE INDIVIDUAL PARTICLES, THE HIGHEST BEING FIRST. THE LIST INCREASES IN TOTAL 'H1 VALUEN J l l = ( N N N * ( J T W * 2 l - l ) / 2

DO 1 3 1 * 1 , L E N G T H 1 3 N O D I I ) * 0

DO 11 1=1,JMAXV1 1 I N O I I ) 3 I

0 0 1 0 1 * 1 , NNN 1 0 M S I I ) * I

M S I N N N P U - N S P S P 1 '

0 0 8 K * 1 , L N G T T 10 0 1 I * t , NNN1 F I M . S I I I ♦ l - M S U + l 1 0 2 , 1 . 6 6 6 6

6 6 6 6 S T O P 6 6 6 62 M S i n * M S ( t m 11=1-1

I F ) 1 1 - 1 1 3 1 , 3 2 , 3 2 3 2 0 0 3 J = 1 , I 1

3 M S ( J ) = J 3 1 GO 1 0 A

1 C O N T I N U E

A N S 1 G * 00 0 5 1 = 1 , NNN

5 N S I G = N S I G » M S ( I )N S I G = N S 1 G - N J 1 1 I F ( n S I G ) 8 , 8 , 9

9 DO 1 2 1 = 1 , NNN N P 1 M I s N N N P l - I

1 2 K U M I I = M S ( N P I M I » I X X = I N O ( N S I G ) * N U ( N S I G )

C A L L L 2 C 0 D I K U K , N 0 0 1 1 X X 1 , N N N !

I N O ( N S l G l » l N O ( N S l G ) * l B C O N T I N U E

R E T U R NEND

DIMENSION NCMAXI351,CO167001,C116700),SQMI201»COED135,351,NU(35), 1KUKI8), NOD(6700),I NO I 70),MS I 10),COV{35)tS(10),NJ(35)COMMON NNN,JFORCE,NUMBERCOMMON/BLR I/TJPO,JTW,NUMJ,LNGTOT.NNNHI,NSPS.NSPSP1,JMAXV,JHAXMO, lLENGTH.LNGTTl,JMLTMX,NNNPL,JTH12COMMON/HLK 2/CO,C1,SUM,COED,COV,NCMAX,NU.KUK.NOO.IND,US,1S.NJCOMMON/BLK 3/FJl.FNNDOUBLE PRECISION CO,C1,C, SQM,COED,COV, SOO,FKG,TEMA, TEME,TJPO DOUBLE PRECISION V DUUOLC PRECISION CHECK DOUBLE PRECISION FJI.FNN

SUBROUTINE HOP

IF THE COEFFICIENT OF THE STATE, CO, IS NON-ZERO. THE STATE IS OE- CODEI). THE TWO/BODY HAMILTONIAN THEN OPERATES ON THE STATE. TWO PARTICLES AT A TIME, SO AS TO CONSERVE THE VALUE OF THE TWO PARTICLES, REFERRED TO AS MPAIR THE STATE IS THEN ARRANGED, COOEO ANO SEARCHED FOR, BEING FOUND IN POSITION NP. THE MATRIX ELEMENT IS THEN EVALUATEO IN FUNCTV ANO THE COEFFICIENT OF THE NEW STATE IS AOJUSTEODO 1 0 2 ! = 1 , N U H J

1 0 2 C 1 ( I ) = 0 . D 0

DO 1 0 0 1 * 1 . N U M J I F ( C O I I ) 1 1 0 1 , 1 0 0 , 1 0 1

1 0 1 C A L L C 0 D 2 L ( K U K , N 0 0 1 1 ) , N N N )

* 0 0 0 0 0 1 I P I * 1 , NN N M 1 I P 1 P 1 = I P 1 + 1 0 0 1 ! P 2 = I P I P 1 , N N N M P A I R = K U K ( I P I ) + K U K ( ! P 2 )0 0 1 I S 1 * t , N S P S 0 0 * I S 2 = l , I S l I F 1 1 S 2 - 1 S 1 ) 5 , 4 , 4

5 I F ( I S I * I S 2 - M P A 1 R ) 4 , 6 , 4

6 0 0 7 I K = I , NNN7 MS 1 1 K ) * K U K ( I K )

MS 1 1 P 1 ) * I S I M S ( I P 2 ) = I S 2

C A L L A R R A N G I M S , I C H E C K )

I F ( I C H E C K ) 8 , 4 , 8

8 C A L L L 2 C 0 D I M S , N E M P , N N N )

C A L L S E A R C H I N E H P . l . N P ) H*U1C H E C K * I C H E C K 0 2C l ( N P ) = C 1 ( N P M C 0 C I ) * C H E C K * V I K U K I I P 1 ) , K U K ( I P 2 ) , I S 1 , I S 2 )

4 C O N T I N U E 1 C O N T I N U E

1 0 0 C O N T I N U E

RETURNENO

Page 230: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

D O U B L E P R E C I S I O N F U N C T I O N V I N l . H 2 . N 3 . M A ) COMMON N N N . J F O R C E . N U M B E R C O M M O N / B L K 3 / F J 1 . F N ND O U B L E P R E C I S I O N F M l . F M 2 . F M 3 . F N A . F M . F J . C O F C CO C U B L E P R E C I S I O N F J 1 . F N N

T H E M A T R I X E L E M E N T OF T H E H A M I L T O N I A N I S G I V E N B Y T H E P R O O U C T OF T H E C I E B S C H - G O R D A N C O E F F I C I E N T S F O R T H E P A I R OF P A R T I C L E S B E F O R E AND A F T E R O P E R A T I O N . T H E 2 . DO I S I N C L U D E D I N V SO T H A T T H E N O R M A L I Z A T I O N M I L L A G R E E W I T H T H A T OF OE S H A L I T AND T A L M I WHEN V O . V 2 , E T C . , A R E T A K E N E Q U A L TO U N I T Y , S U C C E S S I V E L Y

V » 0 . 0 0I F ( H I . M 2 - M 3 - M A ! 1 , 2 , 1

2 F H 1 = M 1 F N 2 = M 2 F M 3 = M 3 F M A = H AF M l = F M I - F J l - l . D OF M 2 « F M 2 - F J 1 - 1 . 0 0 -F H 3 = F M 3 - F j l - l . D OF M A = F M A - F J 1 - 1 . 0 0F M = F H 1 + F M 2

F J « 2 * I J F O R C E - 1 )V = V * C O F C G ( F J l , F J 1 » F J , F M I » F M 2 , F M ) P C O F C G I F J 1 , F J 1 , F J , F M 3 . F M A . F M ) * 2 . 0 0

I R E T U R N END

O I M E N S I O N N C H A X ( 3 5 ) » C 0 1 6 7 0 0 ) , C 1 ( 6 7 0 0 ) , S Q M ( 2 0 ) . C O E D ( 3 5 , 3 5 ) , N U ( 3 5 ) , 1 K U M 8 ) . N O D ( 6 7 0 0 ) , I N D ( 7 0 ) , M S I 1 0 ) , C O V ( 3 5 ) , S t 1 0 ) . N J ( 3 5 )

O I M E N S I O N C ( 6 7 0 0 )COMMON N N N . J F O R C E , N U M B E RC O M M O N / B L K 1 / T J P O , J T W , N U M J , L N G T O T , N N N M 1 , N S P S . N S P S P l , J M A X V , J M A X M O ,

I L E N G T H . L N G T T l , J M L T M X , N N N P I , J T W 1 2 C O M M O N / B L K 2 / C O , C 1 , S C M , C O E O , C O V , N C H A X , N U . K U K , N 0 0 , I N O , M S ,

I S , N JO O U B L E P R E C I S I O N C O . C I . C . S Q M , C O E O , C O V » S O D , F K G , T E M A , T E H E , T J P O

SUBROUTINE JPLUS(C)

I F T H E C O E F F I C I E N T C I S N O N - Z E R O , T H E S T A T E I S O E C O O E O ANO E A C H S U C C E S S I V E TERM I S I N C R E A S E D . T H E NEW WORD I S T H E N A R R A N G E O ,S E A R C H E D F O R ANO F OU ND I N P O S I T I O N L E X . T H E C O E F F I C I E N T OF T H I S S T A T E I S 1 H E N A D J U S T E D A C O I T I V E L Y W I T H T HAT O F T H E ONE J U S T O P E R A T E D O N , ANO U S I N G T H E A R R A Y SCM W H I C H WAS P R E P A R E D I N P R E L I H

N U M J P 1 = N U M J * 1 0 0 6 K = N U M J P 1 . L E N G T H

6 . C ( K I * 0 . DO

M S I l ) = N S P S P 1 DO b M = I . J M A X M O L M A X = N C M A X I H )

DO 5 L = 1 » L MAX L N X = L * N U ( MI I F ( C I L N X ) ) 4 , S , 4

4 C A L L C O O 2 L I K U K , N O 0 I L N X ) , N N N ) 0 0 7 I e 1 , NNN

7 M S ( I ♦ I ) = K U K ( I )

DO 1 1 = 2 . N N N P I I F ( M S I 1 1 - M S I 1 - 1 ) 4 1 ) 2 , 1 , 6 6 6 7

6 6 6 7 S T O P 6 6 6 7 2 H S ( I ) = M S ( I ) . l

DO 8 J » 1 , N N N 6 K U K t J ) = M S t J * I )

C A L L L 2 C 0 D ( K U K . N E M P . N N N )

C A L L S E A R C H ( N E H P , M * l , L E Q )

L E X » L E Q . N U ( H * 1 I I X X - M S I I ) - IC I L E X ) = C I L E X ) * C I L N X ) * S Q M I I X X ) M S ( I ) = H S ( I » - 1

1 C O N T I N U E5 C O N T I N U E

R E T U R NENO

159

Page 231: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

noon

SUBROUTINE SCHMIT01 MENS I ON NCMAX(35).CO(6700) .Cl(67001•S Q M(20).COED(35.35)»NU(35) , 1K U K 1 8 ) . NOO(6700).IND(70).MS( 10).COV(35)« S( 10),NJ(35)01 MENS I ON YI2500),AST<70,70)COMMON NNN.JFORCE,NUMBERCOMKON/BLK l/TJPO.JTWfNUMJ.LNCTOT.NNNMlfNSPS.NSPSP1.JHAXVtJMAXMO. 1 LENGTH,LNGTT1,JMLTMX.NNNPI,JTW12 COMMON/BLK 2/CO.Cl.SQMfCOCO.COV.NCMAX »NU»KUK.NOD,INO.MS.1S.NJ C 0 M M 0 N / B L K 5 / Y . A S T C 0 M M 0 N / 6 L K 6 / K E R R S I 7 ) . N O O R U HD O U B L E P R E C I S I O N C O , C I , C . S Q M . C O E O . C O V , S O D . F K G , T E M A , T E M E . 7 J P O D O U B L E P R E C I S I O N Y , A S 7 , 7 E M P , S I

C D U E T O T HE L A C K OF A D E Q U A T E C O R E S T O R A G E . A O V A N T A C E I S T A K E N OF T H EC S Y M M E T R I C N A T U R E OF T H E N O N - O R T H O N O R M A L I Z E O A M P L I T U D E S OF S T A T E S ANOC H A M I L T O N I A N M A T R I X E L E M E N T S . I N S T E A D O F C R E A T I N G AN A R R A YC D I M E N S I O N E D AT ( J M L T M X , J M L T M X , J M A X V ) , ANO H A V I N G T H O S E E L E M E N T S B E L O WC T H E D I A G O N A L ! I N T H E F I R S T TWO S U B S C R I P T S ) . AN A L G O R I T H M ( I N O E X ) I SC U S E D F O R L O C A T I N G THE P O S I T I O N I N T H E F I C T I T I O U S A R R A Y A N D T HEC S M A L L E R A R R A Y Y I S U S E D I N S T E A O

I N D E X ( 1 1 , 1 2 ) = N U M B E R * ( M I N 0 ( 1 1 . 1 2 ) - 1 1 + M A X O I 1 1 . 1 2 > - I M [ N 0 ( 1 1 , 1 2 ) • 1 ( M I N O I 1 1 , I 2 ) - l ) 1 / 2

MAX I N D = I N D E X ( N U M B E R , N U M B E R )L 0 N G - 2 * L E N G T H

C A L L I N V E R T ( C O E D , J M A X V . 3 5 . O E T E R M )W R I T E ( 6 , 1 0 0 1 I C E T E R M _

R E W I N D 2 R E W I N D 3C A L L M Y t O t n , 1 , 0 , 0 1 0 0 1 1 1 = 1 , N U M B E R I F I I l . L T . N O O R U M I G C TO 4 + 3

R E A D ! 2 ) I CO I I I . 1 = 1 , L E N G T H )R E W I N D 2 GO TO 4 4 4

4 4 3 C A L L MY I 0 I 4 , 3 , C O , L O N G )I F I K E R R S I D . E Q . O I G C T O 4 4 4 W R I T £ ( 6 , 1 0 0 2 ) K E R R SS T O P

4 4 4 C A L L M Y I 0 I 4 , 1 , 0 , 0 1 00 1 1 2 = 1 , 1 1I F I I 2 . L T . N C O R U M I G O T O 4 4 5 R E A O I 2 ) ( C l 1 I ) . 1 = 1 . L E N G T H )GO TO 4 4 6

4 4 5 C A L L M Y I 0 I 4 . 3 . C 1 . L 0 N G I I F I K E R R S I I ) . E O . O > G O T O 4 4 6 W R I I E 1 6 . L 0 0 2 1 K E R R SS T O P

T H E S C A L A R P R O D U C T S OF A L L T H E S T A T E S A R E F O R M E D F O R A G I V E N H V A L U E . N OT E T H A T T H E R E I S NO M - M I X I N G ANO W I T H I N A G I V E N M S U B V E C T O R T H E P K C O U C T S A R E 1 - 1 , 2 - 2 , 3 - 3 , E T C . , B E C A U S E O F T H E O R T H O G O N A L I T Y OF T H ED I F F E R E N T M ' S

4 4 6 0 0 2 M = I , J M A X V

r% n o

C 0 V I H I - 0 . 0 0 N C M - N C M A X ( M )DO 2 1 = 1 , NCM N U M X = N U ( M ) ♦ I

2 C O V I M ) = C O V I M ) + C 0 ( N U M X I * C 1 ( N U M X )1 W R I T E I 3 ) ( C O V t M ) , M = 1 , J M A X V )

C O V F O R M S T H E I N H O M O G E N E O U S P A R T O F T H E L I N E A R E O U A T I O N S T O B E S O L V E O , R E S U L T I N G I N T H E A M P L I T U D E S , Y , A S D I S C U S S E D A B O V E . N O T E T H E T R I ­A N G U L A R N A T U R E O F C O E O , W H I C H WAS P R E P A R E D I N P R E L I H

R E W I N D 8 R E W I N O 9N U M B = J M L T M X .0 0 2 S 1 M = l , J M A X V N X = N J ( M )I F ( N X . E Q . O ) G O T O 2 5 1

R E W I N O 3 S4 4 9 0 0 5 l T l = l , N U M B E R

I N O I I T 1 ) = 0 0 0 5 I T Z = I , N U M B E R I F I I T 2 . G T . I T l ) GO T O 5 R E A D ! 3 ) I C O V ( J ) , J = 1 , J M A X V )K = I N D E X ( I T I . I T 2 )YIK I=0.00 OU 3 1 = 1 , J M A X V

3 Y ( K ) « Y ( K ) + C 0 E D ( M , 1 ) * C O V I 1 1 5 A S I I I T 1 , 1 7 2 1 = 0 . 0 0

C A S C H M I D T O R T H O N O R M ! L I Z A T I O N I S D ONE ON T H E S T A T E S

1 = 14 K » I N O E X I I , I )

I F ( Y ( K ) . G T . 1 . 0 - 4 ) G 0 T O 6 1 = 1 + 1I F I I . G T . N U M B E R ) G O TO 6

GO TO 4 6 A S T ( I . I ) = 1 . 0 0 / D S Q R T ( Y ( K ) )

I P l = I * l INOII 1 = 1I F ( N X . L T . 2 ) G 0 TO 7 8 11 = 10 0 1 1 1 = I P I , N U M B E R1 M l - I - 1i m = m iA S T I I , I ) = 1 . 0 00 0 7 J = 1 , I M 1I F I I N D l J I . E 0 . 0 1 G 0 TO 7T E M P = 0 . 0 0N X 1 = 00 0 8 0 K 2 = 1 , 1 1

8 1 K 4 = N X 1 + K 2 I F ( 1 N 0 ( K 4 ) . N E . 0 ) G 0 T O 8 2 N X l = N X mGO TO B I

8 2 K = I N O E X ( I , K 4 )L = M A X 0 ( K 4 , J )N X 2 = 0DO 6 0 K l = l , 1 1

8 3 K 3 = N X 2 * K L

091

Page 232: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

IF(INO(K3) . NE.01GO TO 84 NX2=NX2*1 GO TO 83 84 IFIK3.LT.L)GO TO 80T E M P = T E M P * A S T < K 3 , K 4 ) * A S T { K 3 , J ) * Y ( K )

8 0 C O N T I N U EA S T ( I , J 1 = - T E M P

7 C O N T I N U E

T E M P = 0 . 0 0 0 0 9 2 J 1 = 1 , II F ( A S T I J 1 , J 1 ) . E Q . 0 . D 0 ) G 0 T O 9 20 0 9 1 J 2 = I , II F I A S T I J 2 , J 2 ) . E Q . O . O O ) G O T O 9 1 J * I H D E X < J 1 . J 2 I

9 T E M P = T E M P . A $ T ( I , J 1 ) * A S T ( I , J 2 ) * Y ( J )9 1 C O N T I N U E9 2 C O N T I N U E

1 F H E M P . G T . 1 . E - 0 4 ) GO TO 1 0 0S 1 * 0 . 0 0GO TO 1 0 1

1 0 0 S I “ I . O O / O S Q R T I T E M P I I N D ( l l = l1 1 » 1 1 P I

1 0 1 0 0 1 0 J = l , l1 0 A S T I I , J ) * A S T 1 1 , J ) * S 1

1 F 1 1 1 • E Q . N X ) G 0 TO 7 81 1 C O N T I N U E

W R I T E 1 6 , 5 0 0 0 ) 1 1 . NX 5 0 0 0 F O R M A T ( 2 1 5 )8 W R I T E ( 6 , 1 0 0 1 ) t (A S T ( I , J ) , J « I,N U M B E R ) , 1 = 1 . N U M B E R )

W R I T E ( 6 . 1 0 0 1 ) ( Y I K ) , K « 1 , M A X I N 0 )1 0 0 1 F 0 R M A K B D 1 5 . T )

N J ( M l = 0N X * 0GO TO 2 5 1

7 8 N U M 8 = M A X 0 ( N U M B , I )w R I I E I B ) ( I A S T ( I , J ) , J = 1 , N U M B E R ) , 1 = 1 . N U M B E R )W R I T E 1 6 , 1 0 0 2 ) ( I N D ( J ) , J = 1 . N U M B E R )

1 0 0 2 F O R M A T I 1 X . 1 0 0 I 1 )W R I T E ( 9 ) I I N D l J ) , J » 1 , N U M B E R )

2 5 1 C O N T I N U E

N U H B E R o NUMBR E T U R NE N D

no no

SUBROUTINE STPTWOD I M E N S I O N N C M A X 1 3 5 ) , C 0 ( 6 7 0 0 ) , C l ( 6 7 0 0 > , S O M I 2 0 ) , C O E O I 3 5 1 3 5 ) , N U I 3 5 ) «

1 K U K ( 8 ) , N O O ( 6 7 0 0 ) , I NO 1 7 0 ) , MS I 1 0 ) , C O V ( 3 5 ) , S 1 1 0 ) , N J I 3 5 )0 1 M E N S I O N Y ( 2 5 0 0 ) . A S T I 7 0 , 7 0 ) , H { 7 0 , 7 0 )COMMON N N N . J F O R C E , N U M B E R

C O M M O N / B L K l / T J P O , J T W , N U M J , L N G T O T , N N N M l , N S P S , N S P S P 1 , J M A X V , J M A X M O , 1 L E N G T H . L N G T T 1 , J M L T M X , N N N P 1 , J T W 1 2

C O M M O N / B L K 2 / C 0 . C 1 , S O M , C O E O , C O V , N C M A X , N U , K U K , N O O , I N O , M S ,1 S . N J

C 0 M M 0 N / B L K 5 / Y , A S T C O M M O N / 0 L K 6 / K E R R S 1 7 > , NODRUMO O U O L E P R E C I S I O N C O , C 1 , C , S O M . C O E D . C O V , S O D , F K G , T E H A , T E M E , T J P O O O U B L E P R E C I S I O N Y , A S T , T E M P , S I

-I N O E X 1 1 1 , 1 2 1 = NUMB E R * ( M I NO ( I I , I 2 ) - 1 ) » M A X 0 ( I 1 , I 2 ) - I M I N 0 ( I 1 , 1 2 ) * l ( M INO(11,121-111/2

H A X I N U = I N O E X ( N U M B E R , N U M B E R I L 0 N G = 2 * L E N G T H N U M B = J M L T M X . J M L T M X / 2

R E W I N D 1 R E W I N D J0 0 1 0 1 1 1 * 1 , N U MB E R R E A D I I H C H I I , 1 * 1 , L E N G T H )

1 0 0 C A L L M Y I 0 I 4 , 1 , 0 , 0 )R E W I N D 2 00 101 12*1,11 I F I I 2 . L T . N C D R U M ) GO T O 1 4 4 7 R E A D 1 2 ) ( C 0 ( l ) , l = l , L E N G T H )GO TO 1 4 4 8

1 4 4 7 C A L L M Y I O ( 4 . 3 . C O , L O N G 1I F ( K E R R S U ) . E Q . 0 ) G 0 T O 1 4 4 8 W R I 1 E ( 6 . 5 0 0 0 1 K E R R S

5 0 0 0 F OR MA T I 7 I 5 1 S T O P

T H E N Q N - O R T H O N Q R M A L l Z E O H A M I L T O N I A N P R O D U C T S A R E F O R M E D I N C O V , MlT H T H E SAME T Y P E OF M - S E L E C T I O N R U L E S A S F O R C O V

1 4 4 8 0 0 1 0 2 M = l , J M A X V C O V ( M 1 * 0 . 0 0 N C M = N C M A X ( M IDO 1 0 2 1 = 1 , NCM N U M X = N U ( M 1 ♦ I

1 0 2 C 0 V ( M ) * C 0 V ( M ) + C 1 ( N U M X ) * C 0 I N U M X )1 0 1 MR I T E ( 3 ) ( C O V ( M ) , H * 1 , J M A X V )

A G A I N T H E T R I A N G U L A R E Q U A T I O N S A R E S O L V E D , T H I S T I M E F O R T H E N O N - U R T H O N O R M A L I Z E O M A T R I X E L E M E N T S , V

R E W I N D 6 R E W I N D 9DO 2 5 1 M = l , J M A X V N X = N J ( M lI F ( N X . E O . 0 ) GO TO 2 5 1 R E AO ( 9 1 ( I N D U l , J = 1 . N U M B E R )

1 4 4 9 R E A D ( 8 ) ( ( A S T I I , J ) , J = 1 . N U M B ) , 1 = 1 , N U M B )R E W I N D 3

191

Page 233: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

o o

0 0 1 5 I T l » l . N U M B E R 0 0 1 5 I T 2 » 1 , N U M B E R I F ( I T 2 . G T . I T 1 ) G 0 T C 1 5 R E A D ! 3 1 ( C O V I J ) , J = 1 .JMAXV) K M N D E X I I T 1 , I T 2 )Y!K)=O.UO 00 103 I = 1» JMAXV 103 YIK)=YIK)+C0E01M,1)*C0VII) 15 H1IT1,IT2)=0.T H E T R A N S F O R M A T I O N M A T R I X A S T I S T H E N A P P L I E D T O T H E H A M I L T O N I A N H A T R I X TO Y I E L D T H E H A T R I X B E T W E E N O R T H O N O R M A L I Z E O S T A T E S

DO 1 6 2 1 1 = 1 , N U M B E RI F U N U U l > . E Q . O I G O T O 1 6 2DO 1 6 1 1 2 = 1 , 1 1I F I I N O I 1 2 ) . E Q . O I G O T O 1 6 10 0 1 7 2 I S 1 = I , N U M B E RI F ( I N D I I S I I . E C . O I G O T O 1 7 20 0 1 7 1 I S 2 = 1 , N U M B E R I F U N D t I S 2 > . E C . O I G O T O 1 7 11 * I N O E X ( I S I . I S 2 )

1 7 H i u , ! 2 1 = H ( I L , 1 2 ) + A S T ( I I , I S 1 1 * A S T U 2 , I S 2 ) * Y ( I )1 7 1 C O N T I N U E1 7 2 C O N T I N U E

1 6 H I 1 2 , 1 1 ) = H I I I , 1 2 )1 6 1 C O N T I N U E1 6 2 C O N T I N U E

K F C R C f c = 2 * l J F O R C E - l )1 = 00 0 3 I 1 = 1 , N U M B E R .I F 11 MO t I L > . E Q . O I G O T O 31 = 1 + 1 J = 00 0 1 J l = l , N U M B E R I F ( l N O U l ) . E Q . O I G O T O 1 J = J + lH I I , J ) = H < 1 1 , J 1 1 I F I J . E Q . N X I GO T O 2

1 C O N T I N U E2 I F ( I . E O . N X I GO TO 43 C O N T I N U E4 W R I T E 1 1 0 , 1 0 0 0 1 J T W , N N N , K F O R C E , M , N X , I ( H I I . J ) , J - l . N X > , ! • 1 , N X >

W R I T E ! 6 , 1 0 0 0 1 J T W , N N N , K F 0 R C E , M , N X , « ( H ( I , J ) , J » 1 . N X ) , I - 1 , N X )1 0 0 0 F O R M A T U X , 1 2 , 1 1 , 3 1 2 , 5 E 1 4 . 7 / I 1 0 X , 5 E 1 4 . 7 ) )

2 5 1 C O N U N U E

R E T U R NEND

I

OU

U

S U B R O U T I N E C 0 D 2 L ( K U K , N E M P , N N N ) O I M E N S I O N K U K I B l L E H P - N E M P DO 1 1 = 1 , NNN J = 6 * t + 6

1 K U K I I ) = I S H I F T U S H I F T ( L E H P , J ) , - 5 4 )R E T U R NE N D

S U B R O U T I N E L 2 C 0 D I K U K , N E M P , N N N )D I M E N S I O N K U K ( B )I F I N N N . E Q . 8 1 G 0 TO 2 N N N P 1 = N N N + 1 0 0 1 I = N N N P 1 , 8

1 K U K I I 1 = 02 NEMP=KUKI8) + ISHIFT(KUK(7),61♦ISHIFT(KUK(6)»t2)+ISHIFT(KUK(51,18)4 1ISHIF T(KUK(4I,24) + ISHIFT 1KUK(31,30)♦!SHIFT(KUKt 2),36)+ISHIFTIKUKt 21) ,42)R E T U R NENO

SUBROUTINE ARRANGIMS, IC)OIMENSION NCHAX1351,CO 16700),C116700),SOMI20),COEOI35,35>.NU<35). 1KUKI8), NOD 16700),INDI70),MSI 101, COVI35>,SI10),NJI35)COMMON NNN,JFCRCE,NUMBERCOMMON/BLK 2/CO,C1,SOM,COEO,COV,NCHAX,NU,KUK,NOD,I NO,MS,1S.NJDOUBLE PRECISICN CO,Cl,C,SQM,COEO,COV,SOD,FKG,TEMA,TEME,T J P O

T H E A R R A Y MS I S P L A C E O I N O R D E R S O T H A T T H E L A R G E S T T E R M I S H S f l ) . IF. A N Y TWO T E R M S A R E E Q U A L I C I S G I V E N T H E V A L U E Z E R O . O T H E R W I S E 1 C I S - 1 F O R AN ODD P E R M U T A T I O N , AND + 1 F O R AN E V E N P E R M U T A T I O N

NNNMl=NNN-lIC-17 1 = 12 IF(MStt)-MSII+l))6,4,l1 IF 1 1—NNNM1) 3 , 5 , 53 1=1+1 GO TO 26 N=HSI 11MSII I=MS11+1)

MS 1 1 + I ) = N IC=-IC GO TO 74 IC-05 R E T U R N ENO 162

Page 234: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

non

S U B R O U T I N E S E A R C H I N E M P . M . L E Q )01 PENSION NCMAX(35)<C0(6700),C1(6700),SQM(20),C0ED(35»35),NU(35), 1KUX(8).NOOI6700), I NO(70).MS 110),COV(35),S( 10),NJ(35>COMMON N N N . J F C R C E . N U M B E RC O M M O N / B L K 1 / T J P O . J T W . N U M J , L N G T O T . N N N M 1 , N S P S . N S P S P 1 » J M A X V . J M A X M O .

1 L E N G T H . L N G T T 1 , J M L T M X . N N N P l , J T W 1 2 C O M M O N / B L K 2 / C O , C 1 , SQM., C O E D , C O V , N C M A X , N U . K U K , N O D , I N O , M S ,

1 S . N JD O U B L E P R E C I S I O N C O , C 1 , C , S Q M , C O E O . C O V , S O O , F K G , T E M A , T E M E , T J P O

T H E WORD N E MP I S S E A R C H E D F O R I N T H E L I S T N O O . I F T H E WORD I S L A R G E R T H A N T H A T I N T H E L I S T T H E S E A R C H S K I P S 1 0 P O S I T I O N S , I F S M A L L E R , T H E S E A R C H I S C O N T I N U E O B A C K W A R D , U N T I L T H E WORD I S F O U N D I N P O S I T I O N L E Q

M E M P = N E M P I B = N U ( M ) * 1 I E = l B * N C H A X ( M ) - l I E Q = 1

6 I F ( N E M P - N 0 0 t I B ) ) l , 2 , 3

3 I B = I B ♦ 1 0 L E C = L E Q * 1 0 I F ( I B - I E ) 6 , 6 , 1

1 DO 5 1 = 1 , 9 L = I1 E N = I B - II F ( NE M P - N O O ( I E N ) ) 5 , 7 , 5

5 C O N T I N U E

W R I T E ( 6 , 1 0 ) M , L E Q , L 1 0 F 0 R M A T ( 3 ! 6 , 2 2 H E Q U A L I T Y - S E A R C H - F A I L E O )

W R I T E ( 6 , 2 1 2 1 1 NE MP 2 1 2 1 F 0 R M A T I I 1 7 )

0 0 2 2 1 = 1 , L E N G T H 2 2 W K I T E I 6 , 2 2 2 4 ) 1 , N O O ( I )

2 2 2 4 F O R M A T ( 1 5 , 1 1 7 )S T O P

7 L E Q = L E Q - L2 R E T U R N

E N D

S U B R O U T I N E M Y I O I I T A P E , M A N A G E , A R R A Y , N U M B E R )D I M E N S I O N A R R A Y ( N U M B E R )C 0 M M 0 N / B L K 6 / K E R R S ( 7 ) . N O O R U M

GO TO ( 1 , 2 , 3 ) . M A N A G E1 C A L L D R U M I 0 ( 5 L T A P E 4 , 6 L R E W I N 0 , 0 . 0 , 0 , I R E S P , K E R R S )

R E T U R N

2 C A L L 0 R U M I 0 ( 5 L T A P E 4 , 5 L U R I T E , 0 , N U M B E R , A R R A Y . I R E S P , K E R R S )R E T U R N

3 C A L L 0 R U M 1 0 1 5 L T A P E 4 , 4 L R E A 0 . 0 , N U M B E R , A R R A Y , I R E S P , K E R R S ) R E T U R NE N D

ONO J

Page 235: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Z 30-4 39

55o»?3>SS5S ►-»»- -g -g «g gi -g s » (M>uw v> s s n -4 -j -j o fg rg(✓> CD <✓> 03

,, ^ ^ a x > * O N p rg -g g t rg •-

Xni y< ® > 73 • o > sn 73 X

-4 30m —• v» o-4 X

-403i i ( .-4 C</* </*>

jo -nc <3 •

73O

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> •o- o r“ x m > > t * 73

co a > c

*ooo-n>30>-<

X X x w ™I i » O C D O X X ^ X H K H C O X t » 2 ^ •g-grgx> -wCr,'X 'X f g X ' s n > * - r v * / * o o ) > w n ^ h

o x x ♦ ♦ mi ♦ ♦ o i a>CT> m m X r - x * X * X fg XUJ X X P* ► - W X rg wco m -g w ►

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o o o o o o o o o o o o oX 3 0 X X » 7 3 X 30 3 0 X ^ 7 3 X X 3 3 3 X 3 2 X 3 3 3 3 3o o o c o o o o o o o o oo o o o o o o o o o o o or o p ' O c a g ^ v ^ v w N N ' Oo o o o o o o o o o o o o

m c s n o o o o o o o o o nZ c * C O O O O O O O O O OO V 1 2 Z 2 Z 2 Z Z Z Z Z Z

=- rg rs; * -g x* O N O V I M V I

»— N> O ' w O M N - j X* x* fsj O O ^ V) oX- O OO O OO O o O o o o o o o o o c o o o o oUlNfO O O X ' O 03 CD

N O O r j -T* u:o O r -lt> u*. -g O • - fg »—• Xs ST>o o ►-S' \J\ &o N) fwO X- X-o o oO V O o o o o o o o o o o o o o o o o o oo rsj ►- O O X' CC 03 03

O LWrg »— w * - o t—S3) O is; O fs> o rg O X' o o o o o o o o o o o o o ^ *+ * oCC CD

rg rgfg rgo osn v/if g rg x* g rg ► - sn » - fg »— f g q**- oO X*o o o o o o o o o o o o o o X* rg cd a

t - i / i o r ^ c . i / i ^ L v w w r z w-o > X X X •o X > t r o x x o o

O’ «g *g rg -g •4 -g > *g

m r * 3 CD XZ CD X rg rg X X 4 9 X I / I 9 H-4 O* rg rg « -g -g >o **

•» ♦ C. 1 ♦ 3X p*

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491o o o o o o o o o o o o o o o o o o o o o o o o o o o o oX X X X X X X X D O X X X T J X X X X X X X X X X X X X X X X X T r T t T t t X I C T ^ C ^ J t - C T - C - C C I - C T C ^ T C t o o o o o o o o o o o o o o o o o o o o o o o o o o o o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 * 3 0 0 0 0 < A < o x a a a ( c a o c t a c c - g * g - g - g - g * * w * g -+i'~j'~4OO0-oO0‘0' p'OOftiNO'XXwMw'C'JCLgOu'XuMM'O'XfflgO'ViXwQ O C Q Q O n Q o o r * ) r . a n n n n r » n r » f t r t r v r t n r t / > « i ^

Page 236: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

T h i s c o de w a s d e s i g n e d f o r u s e on t h e C o n t r o l D a t a

C o r p o r a t i o n 3 40 0 at T e l - A v i v U n i v e r s i t y , Is r a e l . T h e r e q u i r e d

i n p u t is as f o l l o w s :

(a) A t i t l e c a r d to be p r i n t e d o n the o u t p u t (80 c o l u m n s ) .

(b) J T W , N N N - T w i c e th e p a r t i c l e a n g u l a r m o m e n t u m (JTW),

a n d th e n u m b e r of p a r t i c l e s (NNN) i n (213) f o r m a t .n

(c) NJ - T h e m u l t i p l i c i t y o f J - s t a t e s in th e (/) c o n ­

f i g u r a t i o n i n (2413) f o r m a t .

(d) A N G L E - T h e a r r a y o f l i n e a r m i x i n g p a r a m e t e r s f o r

t h e p a i r i n g a n d q u a d r u p o l e f o r c e s . A N G L E = 0 c o r r e s p o n d s to p u r e

p a i r i n g a n d A N G L E = 1 to a p u r e q u a d r u p o l e f o r c e .

(e) H - O u t p u t f r o m the p r o j e c t i o n c o de f o r e a c h v a l u e

o f th e t w o - b o d y a n g u l a r m o m e n t u m .

(f) T I T L E S - 20 c o l u m n t i t l e s a p p e a r i n g on t h e e n e r g y

l e v e l d i a g r a m s f o r e a c h v a l u e of th e m i x i n g p a r a m e t e r s u p p l i e d

t o A N G L E .

P r o c e s s i n g p r o c e e d s as f o l l o w s:

(a) T h e f i r s t t h r e e d a t a c a r d s a r e r e a d in.

(b) R a c a h c o e f f i c i e n t s a r e c a l c u l a t e d f o r the q u a d r u p o l e

f o r c e .

(c) A N G L E is r e a d in.

(d) T h e p a r a m e t e r i z e d H a m i l t o n i a n is r e a d in, a n d th e

p a i r i n g a n d q u a d r u p o l e f o r c e s a r e c o m b i n e d .

(e) T I T L E S a r e r e a d in.

(f) T h e H a m i l t o n i a n f o r e a c h v a l u e o f t o t a l a n g u l a r m o ­

m e n t u m is d i a g o n a l i z e d b y the g e n e r a l p u r p o s e s u b r o u t i n e H D I A G

165

2 . A n a ly s is Code

Page 237: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

(v. A p p e n d i x B - I I I ) . If A N G L E = 0 th e e i g e n v e c t o r s a r e s t o r e d

f o r u s e i n s e n i o r i t y a n a l y s e s . If A N G L E = 0 , th e o v e r l a p s w i t h

t h o s e f o r e A N G L E = 0 ar e c a l c u l a t e d , r e s u l t i n g in t h e s e n i o r i t y

c o m p o s i t i o n s o f th e e i g e n s t a t e s of th e H a m i l t o n i a n .

(g) E i g e n v a l u e s ar e s t o r e d f o r t r a n s m i s s i o n to the

p l o t t i n g r o u t i n e .

(h) D I A G R M is c a l l e d , w h i c h g e n e r a t e s o u t p u t i n th e

f o r m o f e n e r g y l e v e l d i a g r a m s (v. A p p e n d i x B - I I I ) .

166

Page 238: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

PROGRAM SPECTRUM 01 MENS I ON V(13.13 >,U(13,13),PIVOT<13>,IP IV0TI13), T ( 201 01 MENS I ON H(13,13).ENERGY(28,100),NJ(28),W(10)•SENIOR<1 3 , 5 )0 1 ME NS I ON P L O T ( 1 5 0 0 ) , J C O U N T I 1 5 0 0 )D I M E N S I O N P R 0 8 L M ( 2 0 ) » T I T L E S ( 5 , 1 0 )0 1 MEN S I ON A N G L E ( 9 ) , N O S T A T I 2 8 , 5 ) , N U M S R I 2 B )D I M E N S I O N O C C U P Y ( 1 3 )L O G I C A L F I R S T , O C C U P Y

CC G ( F L ) = - F L * I F L + 1 . ) / S O R T I C 2 . * F l - l . ) * F L * ( F L * l . » ♦ ( 2 . * F L * 3 . »>

CF I R S T * . T R U E .

1 0 0 0 R E A 0 ( S , l 0 0 9 ) l P R 0 B L M ( n » I = l , 2 0 )1 C 0 9 F O R M A T ( 2 0 A 4 )

I F ( E O F , 5 1 7 3 , 4 0 0 4 0 0 W R I T E ( 6 . 1 0 0 2 1 P R O 0 L M

1 0 0 2 F O R M A T ! 1 H 1 . 2 0 X . 2 0 A 4 I R E A 0 1 5 . 1 0 0 1 ) J T W . N N N

1 0 0 1 F O R M A T I 2 4 I 3 )S P J = F L 0 A T ( J T W 1 / 2 .J T W 1 2 = ( J T W . D / 2 T J P t = J T w M F J T W 1 2 = J T W 1 2 M O O U L = M O O ( N N N , 2 ) ■0 1 V I D E " F L O A T ( ( N N N - M O O U L I * ! J T W - N N N - M 0 0 U L + 3 ) > / I 4 . * F J T W 1 2 )

CJ M A X V " ! N N N * ( J T W - N N N + 1 ) * 2 ) / 2 R E A D I 5 , 1 0 0 1 ) I N J ( J ) , J « l . J M A X V )j m l t m . x = o NUMBE R = 0 0 0 3 9 J = l , J M A X V N X = N J ( J )J M L T M X " M A X O t J H L T M X . N X )

3 9 N U M B E R = N U M B E R * N X

c0 0 I I J * 1 . J T W 1 2 T 0 I J = 2 * ( J - l )

1 1 W ( J ) * R A C A H ( S P J , S P J . S P J , S P J , 2 . , T 0 T J )WI 7 ) " 0 .R E 0 Y 2 = 0 .L " J T W1 20 0 1 2 L L “ 1 , 2 F L » LR E D Y 2 " R E 0 Y 2 * ( - 1 . ) * * L * S Q R T C 2 . * F L * 1 . ) * R A C A H C S P J , F L , S P J , F L . . 5 , 2 .

C G ( F L )1 2 L » L - 1

R E D Y 2 = ( R E 0 Y 2 * T J P 1 ) * * 2

CI C 0 U N T " 0 N UMP L T " 11 U N I T * 5R E AD I 5 . 1 0 2 5 ) ( A N G L E I J ) . J - 1 , 4 )

1 0 2 5 F O R M A T ( 4 F 1 0 . 4 )DO 6 6 I A N G L E * 1 . 4 R E W I N D 3G P A I R * I A N G L E < I A N G L E ) - l . ) / D I V I D E G Q U A D * A N G L E 1 1 A N G L E ) * R E 0 Y 2

CC C O M B I N E T H E M A T R I C E S F O R D I F F E R E N T J - C O U P I I N G

0 0 5 J F O R C E " I , J T W 1 2 T E M P 2 = 0 .W C O E F = W ( J F O R C E )

oo

D O 5 J - l , J M A X V N X " N J ( J )I F ( N X . E Q . O ) G O T O 5

C

R E A D U U N I T , 1 0 0 3 X ( H ( 1 1 , 1 2 ) , I l - l . N X ) , 1 2 - l . N X )1 0 0 3 F 0 R M A T ( 1 0 X , 5 E 1 4 . 7 )

2 I F ( I U N I T . E Q . 5 ) W R I T E ( 3 , 1 0 0 3 ) ( ( H ( I 1 , I 2 ) , I 1 " 1 , N X ) , I 2 " 1 , N X )

0 0 4 1 1 = 1 , NX K - l l - N X DO 4 1 2 = 1 , 1 1 K = K + N X —I 2 * 1 I E M P 1 = H ( I 1 , 1 2 )

I F ( J F O R C E . N E . I ) G 0 TO 3 E N E R G Y ! J , K ) = 0 .

. I E M P 2 = T E M P 1 * G P A I R3 T E M P I = T E M P 1 * G C U A 0 * W C 0 E F * T E M P 24 E N E R G Y ! J , K ) = T E M P I * E N E R G Y t J , X >5 C O N T I N U E

I F ( F I R S T ) R E A D ( 5 , 1 0 0 9 ) ( T I T L E S ( ! , N U M P L T ) , 1 " 1 , 5 )W R I T E ( 6 , 1 0 0 4 ) ( T I T L E S ! I . N U M P L T I , 1 = 1 , 5 )

1 0 0 4 F O R M A T ! 1 H 0 . 5 A 4 )c

0 0 6 J = l , J M A X V N X = N J ( J )I F ( N X . E O . O ) G O TO 6 MOMEN T = J * 1 1 * M 0 0 U L ) - 1

C A L C U A L T E E I G E N V A L U E S 4 3 M A X 1 N 0 = ( N X * ( N X + 1 ) ) / 2

I F I N X . N E . D G O TO 3 3 3 H I 1 , 1 ) = E N E R G Y ( J , 1 )GO T O 4 4

3 3 3 K = 0 0 0 7 1 1 = 1 , NX 0 0 7 1 2 = 1 1 , NX K = K * 1

7 H I I I , I 2 ) = E N E R G Y ( J , K )1 0 2 0 F O R M A T ( 1 X . 9 E 1 3 . S )

C A L L HO I A G ( H , N X , 0 , U , N R , P I V O T , I P I V O T « 1 3 )

3 3 4 I F ( I A N G L E . NE • 1 1 GO TO 4 5

W R I I E ( 3 ) ( ( U ( I 1 , I 2 ) , I 2 = 1 , N X ) , I I = 1 , N X )0 0 9 4 1 1 = 1 , NX

9 4 O C C U P Y I l l l = . F A L S E .KK = 00 0 9 5 1 1 = 1 , NX I F ( O C C U P Y I 1 1 ) ) G 0 TO 9 5 K 0 U N T R = 1 T E S T = H ( 1 1 , 1 1 )I 1 P I = 1 1 * 10 0 9 6 1 2 = 1 1 P I , N XI F I O C C U P Y I 1 2 ) I G O T O 9 6! F I A B S ( T E S T - H ( I 2 , I 2 ) ) . G T • l . E - 3 I G O T O 9 6K 0 U N T R = K 0 U N T R * 10 C C U P Y ( I 2 ) * . T R U E .

9 6 C O N T I N U E KK = K K ♦ 1N O S T A T ( J , K K ) = K O U N T R

9 5 C O N T I N U E N U M S R I J ) = KK 0 0 8 0 U > 1 , N X

Page 239: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

o o

DO 8 0 1 2 = 1 1 , NX S U M - 0 .0 0 8 1 K » 1 » NX

8 1 S U M - S U M * U ( K , l l ) * U ( K , 1 2 )V ( I I , 1 2 1 - S U M

8 0 V ! I 2 , m = S U M DO 8 2 1 1 “ 1 , NX82 W R I T E 16, 1020)(VI11 ,12 ) , 12-1, NX)GO TO 4 4C

4 5 R E A O ( 3 ) I ( V I 1 1 , 1 2 ) , 1 2 = 1 , N X ) , 1 1 = 1 , N X )0 0 9 7 1 1 - 1 , NX K K - N U M S R I J l 12-00 0 9 7 1 = 1 , KK K K K - N O S T A T ( J , I )S U K 2 - 0 .0 0 4 6 1 = 1 , K K K 12=12*1 S U M 1 - 0 .0 0 4 7 K - l . N X

4 7 S U M 1 = S U M 1 » U ( K , I I ) * V ( K , I 2 )4 6 S U M2 = S U M . 2 * S U M 1 * S U M I 9 7 S E N I 0 R 1 I 1 . 1 I - S U M 2

S T O R E E I G E N V A L U E S I N T H E A R R A Y P L O T 4 4 DO 8 1 = 1 , N X

I C O U N T - I C O U N T ♦ I P L O T ! I C O U N T ) * H I I , I )

8 J C O U N T I I C O U N T I - M O M E N TI F I I A N G L E . E C . l . O R . N X . E Q . D G O T O 6 W R I T E 1 6 , 1 O S O ) MOMENT

1 0 5 0 F O R M A T 1 / 4 H * J = , 1 3 )I F I M O G U L . E C . 1 ) W R I T £ 1 6 , 1 0 5 1 )

1 0 5 1 F O R M A T t l H * , 6 X , 2 h / 2 / )I F ( M O G U L . EC*. 0 ) W R I T E ! 6 , 1 0 5 2 )

1 0 5 2 F O R M A T ( 1 H * / 1 DO 4 8 1 1 = 1 , NX

4 8 W R I T E ( 6 , 1 0 1 8 ) 1 1,I S E N I O R I 1 1,12) ,1 2 = 1 , K K )1 0 1 8 F 0 ? . M . A T 1 1 X , I 2 , 1 X , 1 3 F 9 . 5 )

6 C O N T I N U EC

K = ( N U M P L T - 1 > * N U M B E R + 1 I F I H O O U L . E C . D G O TO 5 0 W R I T E 1 6 , 1 0 0 7 )

1 0 0 7 F O R M A T 1 1 H 0 , 6 1 3 X . 6 H E N E R G Y , 7 X , 1 H J , 3 X ) )WRITE<6,1006)I PLOT 1J),JCOUNT( J ) , J = K , ICOUNT)1 0 0 6 F 0 R M A T I 6 I E 1 5 . 7 , 1 3 , 2 X 1 1

GO TO 5 15 0 W R I T E I 6 . 1 0 1 7 )

1 0 1 7 F O R M A T 1 1 H O , 6 I 3 X , 6 H E N E R G Y , 8 X , I H J , 2 X ) )W R I T E 1 6 , 1 0 1 6 1 I P L O T ( J 1 , J C O U N T ( J ) , J - K , I C O U N T )

1 0 1 6 F O R M A T ( 6 1 E 1 5 . 7 , I 3 , 2 H / 2 ) )5 1 I U N I T - 36 5 N U M P L T = N U M P L T « 16 6 C O N T I N U E 1C

N U M P A C - N U M B E R / 1 0 * 15 2 C A L L 0 1 A G R M I P R O B L M . N U M P A G , T I T L E S , N U M P L T - 1 , N U M B E R , P L O T , J C O U N T ,

M C O U L • 3 )CF I R S T = . F A L S E .

GO TO 1000 73 STOP ENO

H1cnCD

Page 240: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

A P P E N D I X B - I I

P A R T I C L E - H O L E C O M P U T E R C O D E

1. I n p u t C o d e

T h i s c o d e w a s d e s i g n e d f o r u s e o n th e I B M 709*1/70*10

D i r e c t C o u p l e d S y s t e m at Y a l e U n i v e r s i t y . It g e n e r a t e s

i n p u t m a t r i x e l e m e n t s of th e o n e - a n d t w o - b o d y p a r t s of

th e H a m i l t o n i a n a n d th e J + o p e r a t o r , i n th e H a r t r e e - F o c k

s c h e m e , i. e . , it t r a n s f o r m s t h e s e o p e r a t o r s f r o m a s h e l l

m o d e l b a s i s to th e H a r t r e e - F o c k b a s i s .

P r o c e s s i n g p r o c e e d s as f o l l o w s:

(a) J N U M , N S P S a r e r e a d in. J N U M is th e n u m b e r of

d i f f e r e n t s i n g l e - p a r t i c l e a n g u l a r m o m e n t a in the s h e l l m o d e l

b a s i s ; N S P S t h e n u m b e r of s i n g l e - p a r t i c l e s t a t e s fo r n e u t r o n s

a n d / o r p r o t o n s .

(b) A l i s t of C l e b s c h - G o r d a n c o e f f i c i e n t s is g e n e r a t e d .

(c) T w o - b o d y m a t r i x e l e m e n t s i n th e s h e l l m o d e l b a s i s

a r e r e a d i n e i t h e r f r o m c a r d s o r a t a p e , c o n t r o l l e d b y a

c o n t r o l ca rd , th e f i r s t f o u r c o l u m n s of w h i c h sa y C A R D o r TA PE.

(d) P R O B L M - a n 80 c o l u m n t i t l e to b e p r i n t e d o n th e

o u t p u t , is r e a d in.

(e) M C O D E - a n a r r a y g i v i n g th e M - v a l u e s o f th e i n d i v i d u a l

p a r t i c l e s t a t e s , is r e a d in.

(f) T h e H a r t r e e - F o c k b a s i s is c h e c k e d f o r p r t h o n o r m a l i t y

to th e a c c u r a c y o f t h i s m a c h i n e . T h e S c h m i d t p r o c e s s is e m p l o y e d .

(g) O n e - b o d y e n e r g i e s a r e r e a d in.

169

Page 241: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

(h) T h e t r a n s f o r m a t i o n to th e H a r t r e e - F o c k b a s i s is

p e r f o r m e d .

(i) O n e - a n d t w o - b o d y m a t r i x e l e m e n t s a n d t h o s e o f J + ,

a l l i n th e H a r t r e e - F o c k b a s i s a r e o u t p u t to b e r e a d i n b y

P H E X C I T , w h i c h f o l l o w s .

170

Page 242: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

D I ME NS 1 3 N R 0 0 T ( 4 , 8 ) , I M U L T ( 2 3 ) , M V A L U ( 8 , 6 3 )D I M E N S I ON C I 4 , 2 3 > , M C 3 D E ( 2 O ) , H F J P L S ! 2 0 , 2 3 ) . H F l B 0 V C 2 0 , 2 0 ) D I M E N S I O N D ! 4 , 2 3 ) , Y ( 2 1 0 > , A S T I 4 0 0 ) , P R 0 B I M ( 2 0 )0 1 ME N S I DY M V A L U E ! 8 , 5 3 , 2 > . N J ( 8 ) , V 3 ! 4 , 4 , 4 , 4 , 8 ) , V I ( 4 , 4 , 4 , 4 , 8 > , T ( 4 ) 0 I M E N S I 3 N B 0 Y 2 1 ! 1 8 3 3 ) , B 0 Y 2 2 ! 1 5 9 6 ) , B D Y 2 3 ( 1 0 8 1 ) , B D Y 2 4 ! 6 1 1 ) ,

8 0 Y 2 5 I 2 1 0 ) , B D Y 2 6 < 5 5 ) , 3 D Y 2 7 ( L O ) , B 0 Y 2 8 ( 1 )COMMON C C < 1 3 , 8 , 5 4 )03J3L E PRECISION C,0,Y,AST,SCAL4R,SJMI,SUM2,TEMP DOJ3LE PRECISION FJ,FM1 ,FM2,FFM,HFJPLS 03J3LE PRECISION ROOTO A T A C A R 0 , T A P E / 4 H C A R D , 4 H T A P E /R E W I N D 4R E A 0 ( 5 , 1 3 3 1 ) I S K I PI F ! I S X I P . G T . 3 ) C A L L R E A D E R ! I S K I P )R E A D ! 5 , 1 3 3 1 1 J N U M , N S P S

1 3 3 1 F 3 R M A M 2 4 I 3 )S 3 R T 2 = S 3 R T ( 2 . ) j n j m s u = j n u m « j n u m

j m A X M = 2 * J N U Mm a d j s t = j m a x m u

ML I M I T = J M A X M - 1 C A L L C C C O E F ( J N U M )R E A 3 I 5 , 1 3 3 3 )HOW I F I H 3 W . E 3 . C A R D I RE AD C 5 , 1 3 3 4 )

1 ( ( 11 I Y D ( J l , J 2 , J 3 , J 4 , J ) , V 1 ( J 1 , J 2 , J 3 , J 4 , J ) , J » l , J M A X M ) , 2 J 4 = I , J N J M ) , J 3 = 1 , J N U M ) , J 2 = l , J N U M ) , J l ° l , J N U M )

1 3 3 4 F D R M A M 5 E 1 6 . 8 )I F ( M 3 w . E 3 . T A P E ) R E A O ( 3 ) V 3 , V l R E A O I 5 , 1 3 0 2 ) S T R N T H 0 0 7 3 J 1 = 1 , J N U M 0 0 7 3 J 2 = 1 , J NUM

7 1 T E M P I = S T R ' I T HI F ! J 1 . E 3 . J 2 I T E M P 1 = 2 . ♦ S T R N T H 0 0 7 3 J 3 = 1 » J NUM 0 3 7 3 J 4 = l , J N U M T E M ? = T E M P lI F ! J 3 . E 3 . J 4 ) T E M P = T E M P 1 * 2 .DO 7 3 J = 1 , J M A X MV 3 I J l , J 2 , J 3 , J 4 , J ) = V 3 1 J l , J 2 , J 3 , J 4 , J ) * T E M P Y 1 ( J 1 , J 2 , J 3 , J 4 , J ) = V 1 ( J 1 , J 2 , J 3 , J 4 , J ) * T E H P

7 3 V 3 ( J 1 , J 2 , J 3 , J 4 , J ) = ( V 0 ( J 1 , J 2 , J 3 , J 4 , J ) * V 1 ( J 1 , J 2 , J 3 , J 4 , J ) ) * . 5CN S P S P = N S P S * N S P S N S P S ? 1 = N S P S P * 1

5 3 0 3 R E A 3 ( 5 , I 3 3 0 1 P R O B L M 1 0 3 3 F ORMA T ( 2 D A 4 )

w R I I E I 6 , 1 3 5 0 ) P R O B L M 1 3 5 3 F O R M A T ! I . H 1 , 2 3 X , 2 0 A 4 )

R E A D ! 5 , 1 3 3 1 I ( M C 3 0 E ( N ) , N » 1 , N S P S )N I C E = 30 3 5 5 N = 1 , N S P S N I C E = N I C E » N S P S P 1

6 5 I M J L T ( N ) = N I C E00 54 J = I,JNUM ,F J = J * J0 0 5 4 M = I , J MAXMF F M = M - J N U MT E M P s F J - F F M * F F MI F ( I F M P . L E . 3 . ) G 3 TO 6 3R O O M J , M ) = D S 3 R T I T E M P IGO T 3 6 4

o o

63 ROOT(J,M)«0.64 CONTINUEC LOWl“1 LI Ml = NSPS 1X1 = 3 L0W2=1 LI M2 = NSPS 1X2 = 3WRITE(6,1010)1313 FORMAT!47H3HARTREE-F3CX (OEFORKEO) SINGLE PARTICLE STATES)00 139 ISPlN-1,3C REMOVE NEXT CARO IF PROTON 1-B03Y .NE. NEUTRON 1-BODY ENERGIESC IF!ISPIN.E3.21G3 TO 102IF! ISPIN.E0.21G3 TO 102GO TO (801,802,99),ISP1N 831 WRITE( 6, 1320)(J,J = l,ML I MIT,2)1323 FORMAT!I3H3STATE NO.,2X,4!11X,2HJ«,11,2H/2))00 I N=I,NSPS I REAOI5,1002)(0!J,N),J°1,JNUM)1002 FORMATI4F10.4)ORTHONORMALI2E THE SINGLE PARTICLE SPACE 00 435 N=1,MLIMIT,2 INDE X =3 KOUNT = 300 432 Nl=l,NSPS H1=MC3DE(.N1)IF(Ml.E3.N1KOUNT=KOJNT*l DO 432 N2=N1,NSPS 1N0EX=IN0EX*I SCALAR»3.IF(M1.NE.N.0R.MC30E(N2).NE.N)G0 TO 402 00 431 J = I,JNUM401 SCALAR=SCALAR*OIJ,Nl)*D(J,N2)402 Y{ IN3EX)=SCALARCALI SCHMITtXOUNT,NSPS,Y,AST)00 405 N1=1,NSPS,2 IF(MC0DE(N1).NE.N)G3 TO 405 00 433 J = I,JNUM SJM1=3.SJM2=0.NJM3ER=Nl-NSPS 00 434 N2=1,NSPS NUM3ER=NUMBER»NSPS IFIMC00EIN2).NE.N)GO TO 404 TEMiP = AST( NUMBER)SJM1 =SdMUTEMP*D( J,N2)SJM2 = SJM2HEMP*0( J,N2*1I404 CONTINUEC<J,NI)=SUM1403 C(J,Nl«l)=SUM2405 CONTINUE00 436 N=1,NSPS 4 36 WRITE(6, 1005 IN,MCODE(N),IC(J,N),J>1,JNUM)1035 FORMAT!16,3X.3H X =,12,2H/2,4E16.7)

C SET JP I HE M VALUE OF THE 2-BODY STATES99 00 103 M«l,JMAXM 103 NJ!MI= 3

Page 243: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

03 105 91=1,9SPS M1»MC0DE(N1)MVALJI=IHULTTN1)03 135 92=L3W2,LIH2 IFI 91.EQ.92)GO 13 105 992=92-1<2M=(Ml♦m; 0DE(N92))/2*l IFtM.LT.llS3 TO 105 9'JM3ER = 9J(M)»1 9 J I M ) = 9 J M B E R MV41JE< M,9UMBER,1)=91 MVALJEIM,9UMBER,2)=92 MVAL J( M, 9UM8ER) =MVALU1*92 105 C39TI9UEIF(ISPI9.EQ.31G3 TO 85 832 READI5,1D32>ITU>,3 = 1,390*1)I F t ISPM.£3.2)33 TO 87 85 HR I (El 5,1006)IT(J) , J = l,J9UM)1335 FORMAT 141H09EUTR09 SI95LE PARTI OLE E9ER3IES - J=1/2,F8.4,5X.7H .3/2,F8.4,5x,7H J«5/2,F8.4,5X,7H J=7/2,F8. 4 , 5X, 5H(MEV)),<R ITE ( 5,1001 19UM3ER 30 T3 85 87 „R I TE(6, 1308)(T(J) , J«I,J9UM)1303 FORMAT( 41H0PR3T09 SI93LE PARTICLE ENERGIES - J« 1/2• F8.4,5X,•7H J=3/2,F8.4»5X,7H J=5/2,F8.4,5X, 7H J=7/2,FB.4,5X, 5H(MEV)»CC BES19 CALCJLAU9G VARIOUS MATRIX ELEMENTS85 03 2 91=L0W1,LIM1 N91=9I-I<1 mi=m; ooein91i M MI =(Ml.MAOJST)/2 MMM1=( IABSMl) + l )/2 9PRIM1=IMULT(91)IMP1=JMAXM*(MMl-l)03 2 92=L0rf2,LlM2 992=92-1<2 H2=MG00E(992)M 92 = tM2.9A0JSTI/2 M 9 92 = ( IAHSIM2)»l)/2 I9?2=I MR I»MM2CC FORM Jf MATRIX ELEMENTSGO T 3 (833,834,32),ISPI9803 TEM»=0.■ IF(92-Ml.9E.2)G3 TO 3 DO 4 J=liJNUM 4 IE9P = IE9P»C( J,91)*C( J,92)*R00TU,MM1)3- HFJPLSI 92, 91 ) = TE9PCC FORM 1-33DY PART OF HAMILTONIAN804 IF(91.Gr.92)GO 13 33 TEMPO.IF19).9E.921G0 13 31 DO 33 J = I, J9UM 30 TEMP=TEMPvttJ,N91)*ClJ, 992 >*T(J). 31 HF130T(99I,N92)=TEM?HF130YI992,991>=TEMP IFIISPIM.E0.21G0 TO 2CC FORM 2-330Y PARI OF HAMILTONIAN32 1FI91.E3.92JG0 TO 233 IF(ISPI9.EQ.2)G3 TO 2

M=(Ml+M2)/2+l IFlM.LT.llGO TO 2 NPRIME = 9PRIMl«-N2 MAX I 9 = 90(M)00 43 NJMB=1,MAXIM 43 IF(MVALJ<M,9UMB).EQ.NPRIME)G0 T3 42 WRITE(6,1234)1234 FORMAT(1 OH STOP 1234)STOP 42 L=9JMR-MAXIM00 23 NJMBER=1, NUMB TEMP3=0.93=MVALJE(M,NUMBER,1)993=93M3=MC00E(9N3)MM3=(M3AMADJSTI/2 . MMM3 =(IAHS(M3)*l)/2 94=MVALJE(M,NUMBER,2)N-9 4 = 94-1 <2 M4 = m;0DE(N.94)MM4=(M4.MA0JST)/2 MMM4=( IABS(M4Ul)/2 IMP4=JMAXM*(MM3-1)+HM4J1CG= 000 53 J1=1,J9UM IEMP1=C(JI.N91I DO 53 J2 = 1,J9UMjicg=j i : g»iIFIJl.Lr.MMMl.0R.J2.LT.MNN2)C0 TO 33 TEMP2=TEM?1*C(J2.NN2)J1PRVM = J102 J 3PR YM =1ABS(J1-J2)J2CGO00 51 J3=l,J9UM TEMP3=TEMP2*C(J3.NN3)DO 51 J 4=1» J9UM J2CG=J2CGtl1F1J3.LT.MMM3.0R.J4.LT.MMM41G0 TO 51TEMP4=TEMP3*C(J4.NN4)J2PRTM0304JMI 9=MAX 01J3PRYM,IABSIJ3-J4))*1 JMAX=MI901J1PRYM,J2PRYM)IF(JMI9.GT.JMAX1G0 TO 51 T EMP = 0.03 6 J=JMIN,JMAX CG11=CG1J1CG,J.1MP2)Ca21=C,IJ2CG.J,IMP6)10 IFMSPI9.E0.3IG3 TO 862TEMP=TEMP*CG11*V1(Jl,J2,J3,J4,J)*CG2l GO TO 6862 TEMP=TEM?.CG11*V0IJl,J2,J3,J4,J)*CG21 6 CONTINUETEMP3=TEMP0*TEMP*TEMP4 51 CONTINUE 53 CONTINUE

25 L = L»MAXIM-9UM8E.R*1GO TD (501,502,503,504,505,506,507,538), 501 8DY21(L)=TEMP0 GO T 3 20

Page 244: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

502 80Y22(L)“TEMPO30 TO 20503 BDY2 3 IL)-TEMPO30 TO 20504 30Y241LI * TEMPO30 TO 20505 BDY25IL)8TEMPO30 TO 20505 B0Y25IL)-TEMPO30 TO 20507 80Y27(LI=TEMPOGO TO 20508 B0Y28IL1-TEMPO20 CONTINUE2 CONTINJE30 ro (21.23.82),I SPIN 21 WRITE(6,2002)2002 FORMAT<27H0NEUTRDN 1-BODY HAMILTONIAN)30 TO 2423 nR IIE I 5,2003)2003 FORMAT(26H0PR0T0N 1-BODY HAMILTONIAN)24 WRITEIS,2001)1 (HFIBOYII,J),J*1,NSPS),1*1,NSPS)2001 FORMArI IX,12F10.6)WRITE(4) (IMF1B0Y(I,J),J=1,NSPS),I=1,NSPS)1F(!SPIN.E9.2)G0 TO 102 BI wRirE(6,10ll)(NJ(M),M=l,JM4XM)1011 FORMAT!13HINEUTRON-NEUTRON M-MULTI PL ICITIES,1114)30 TO 8482 WRITE(5,1012)(NJ(HI,M=1,JMAXM)1012 F.ORMAT(33H1NEJTRON->ROTON M-MULTI PL ICITIES,111 4)84 DO 106 M=1,JMAXMMAXIM-NJTM)IFIMAXIM.E0.0130 TO 106wRirE(S, 2005 )MM\/ALJE<M,NUM3ER,I>,I = l , 2 ) tNUM3ER*l,MAXIM) 2005 FORMAT!17(213,IH,))106 CON!INUElFtISPIN.EO.3130 TO 2725 WRITE(6,2004)2004 FORMAT!35H0NEUTR0N-NEUTR0N 2-BODY HAMILTONIAN)30 TO 2927 wRITE(f>.3232!3232 FORMAT!34HONEUTRON-PROTON 2-B00Y HAMILTONIAN)29 WRITEI4) (NJ(M),H=1,JM4XM)00 SI M-l.JMAXM MAXIM-NJIM)IFIMAXIM.EQ.3IG0 TO 61 • MM , M - 1wRIT EI 5, 1007)MM 1007 FORMAT! HO,3HM =,12,17H (UPPER TRIAN3LEI)WRITE!4) I MmU(M,NJM3ER), NUMBER* I, MAXIM)1 0W= 1LI MM MAXIM*I MAXIM* 11 1/2600 30 TO (SOI,602,503,504,605,606,607,608),M601 WRI TEI 6, 200111 B0Y2K < ) ,<«L3W,LIN)701 WRITEI4) (3DY2l(<),<=L0W,LIM) ,30 TO 61602 WRIIE(6,2001)(B0Y22I<),K*LOW,LIM)702 WRITEI4) <BDY22(<),<-L3W,LIM)30 TO 61603 »RITE(6,2O01)(B0Y23(<),<=lOW,LIH)703 WRITEI 4)’ (80Y23(<),<*L0W,LIM)

GO 70 61604 MR I TE(6,2001)(B0Y24I<I, <«LOH,LIM)704 MR ITE14) <8DY24(<),<=L0W,LIM)GO TO 61605 WRITE(6,2001)(B0Y25(<),X*L0W,LIM)705 WRITE(4) (8DY25IO,<=LOW,LIM)GO TO 61606 WRITE(6,20011(B0Y26IR), K-LOW, LIMI706 WRIT c(4) (BOY2 6 ( 0 ,<=LDW,LIM»30 TO 61607 WRITE(6,2001)(B0Y27(<),<*L0W,LIM)WRITEI4) (BDY27<<),<=L3W,LIM)GO TO 61608 WRITE(6,2001)(B0Y28(<),K*L0H,LIM)WRITE14) (BDY28I<),<=LOW,LIM)61 CONTINUE. IF(ISPIN.EQ.3)G0 TO 109 901 HRITE(6,2000)2000 F0RM4TISH1JPLUS)903 WRITEI6,2001)11NFJPLS(I«J),J=liNSPS),1*1,NSPS) WRITE!4) ( ( HFJPLSfI,J),J*1,NSPS),1*1,NSPS)101 LOWl=NSPS*1limi- nspspIKl-NSPS LUW2-L0WI L I M2 = LI M1 IX2=I XI 888 30 (0 109102 LOWl8 1 LIM1-NSPS

U\=0109 CONTINUE GO TO 5000 STOP tND

Page 245: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SJBR3JTINE SCHM t T (NX*NUM3ER,Y»AST) DIMENSION Y(1) ,ASTI NUMBER,11*1NDI20) D3J3LE PRECISION Y,AST,TEHP, SI LOGICAL IND03 5 -I T1 = 1, NUMBER INDIIT1>=.FALSE.DO 5 IT2 = 1,NUMBER5 ASTI ITl,IT2)=0.1 = 111 = 34 <=NJM8ER+U-ll-U*M-3) )/2 IFIYI<).ST.0.0031)C3 TO 6 1 = 1 + 1IF! I.LE.NUMBER)S3 T3 4 WRirEI6,l(1 F ORM A T I 7rl STOP I)STOP

6 ASTI I,I) = 1.D0/DS3RT(Y(K))1P1 = I ♦ 1INDII>=.TRUE.1FINX.E3.1)S3 T3 78 11 = 1IFI IPl.LE.NUMBERIGO TO 3 wRirE(6 , 2 )2 F QRMA I ( 7rl STOP 2)STOP3 03 11 I = I P1,NUMBER IM1=I-111PI» 11 + I ASTI 1 , I 1 = 1.DO 7 J=1. IHl IFI.N3T.IN0IJ1IG3 T3 T 1EM?=3.NX 1 = 303 93 <2=1,II81 K4=NXl+<2I F ( I stDC <4 >) C3 73 82NXI=NX1+IGO TO 8182 K=LINfcAR(NUMBER,I,K4) l = MAOU4,J)NX 2 = 300 93 <1=1,1183 K3=NX2+<1 IFUND(<3))G0 73 84 NX2 = NX2U• GO T3 8384 IFU3.Lr.LIGn 73 80 TEMP=rEMP+AST(K3,K4l*ASTIK3,J)*Y(K)83'C3NTINJEASTI I , J)»-TEHP7 C3NTINJE1EMP=3.03 42 31=1,1IFIASTIJI,J1).E3.0.)G0 TO 9203 31 J2 = 1,1IFIASTIJ2.J2I.E3.0.IG0 TO 91 J=LINEA1(NUMBER,JI.J2)TEM?=rEMP+AST(I,J1)»ASTII,J2)*YIJ)

91 CONTINUE92 C O N T I N U E I F t r E M P . G T . l . E - 3 4 ) G 3 T O 10 0 Sl = 3.GO TO 131C 100 Sl=l.DO/OSQRTITEMP)INOII I = .TRUE.11 = 11 PI101 03 13 J => 1 , I10 AS r CI, J)=ASTI I , J)+s1 IFI11.E3.NXIRETJRN11 CONTINUE 78 RETURNENO

FUNCTION LINEARINUM8ER,11,12)C N1=MIND(II,I2I-1 N2«MAX0<11,12)LINEAR=NJMBER*N1+N2-INI*1N1+1))/2C RETURNEND

SUBROUTINE CGCOEFIJNUM)COMMON CG(10,8,&4)03J3LE PRECISION FJ1,FJ2,FJ, FM1, FM2, FM,NINHAFC JMAX=2+JNUMNINHAF=-JNUMNINMAF=NINHAF-.5D003 1 J=I, JMAXFJ=J-1FJl=-.5C JPR!ME=3 00 1 J1=1,JNUM FJ1=FJ1+1.00 FJ2=-.5DO 1 J2=1,JNUMFJ2=FJ2+1.00JPRIME=JPR1ME+1C FMI=NINHAF M = 0on 1 Mt=l,JMAX FMUFMl + l.DO FM2=NINMAF 00 1 M2= L * JMAX F M2 = F M2 + I. DO FM=FM1+FM2 H = M + 1c 1 CALL C3FCG(FJI,FJ2,FJ,FM1,FM2,FM,CGUPRIME,J,M1 1C RETJRNENO

Page 246: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

2. PHEXCIT

PHEXCIT is a multi-phase Fortran IV program designed for

use on the IBM 360/44 of the Wright Nuclear Structure Laboratory,

Yale University, its purpose is the calculation of the mixture

of one- and two-particle/hole excitations to the Hartree-Fock

state with an analysis of the individual contributions.

The overlay structure is shown in Figure 25. Phases,

at any given level, are loaded into core (temporally) in the

direction left to right.

(a) R00T2 is the root phase, which is always resident in

core storage. The following subroutines and main program make

up this phase:

PH2 is the main program. Its function is to load all

phases into core at the correct times.

TWOBDY locates two-body matrix elements in the input

data, taking account of the antisymmetry of two-body states,

positive and negative angular momentum z-projections, and

isospin components.

LOCATE finds the correct position of determinantal multi-

particle states in a list of all positive M-states using a bi­

nomial coefficient algorithm.

DECODE accepts a coded one-word description of the multi­

particle state and populates the individual single-particle

states which make it up.

TRIANGLE is a triangular flow output routine for symmetric

or antisymmetric matrices.

S0LVER2 extracts angular momentum components from over-

175

Page 247: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

lap functions with good z-projections by solving a triangu­

lar matrix equation.

BICO produces binomial coefficients.

PLUSJ applies the raising operator successively to any

combination of multi-particle states with the same z-projection

of angular momentum.

(b) READR finds the correct set of input data on the

input tape.

(c) BEGINR controls all sub-phases having to do with

neutrons or protons separately.

(d) PRPARE

PRPARE2 prepares the list of all possible neutron or

proton states with z-angular momentum projection greater than

or equal to zero, and tests these states for their one- or

two-particle nature. It decides which of these states are to

be treated as intrinsic.

CODER accepts individual particle states, generating

a single coded word to identify the multi-particle determinantal

state.

(e) HAMLTN applies both the one- and two-body operators

to the intrinsic states. If the problem is to be solved as a

hole calculation with the shell closed, then the proper addi­

tive adjustments are made for the energy spectra.

(f) FINEE controls the extraction of angular momentum

components from M-overlaps, and the calculation of metrics for.

1-particle/l-hole non-zero M-states.

176

Page 248: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

(g) COMBIN

KOMBINE2 extracts angular momentum components from

M-overlaps for both the neutron (proton) metrics and energy

matrices, generating separate contributions of each state to

the Hamiltonian matrix.

BLEND2 calculates metrics for one-particle/one-hole,

non-zero (positive and negative) M-states.

MINUSJ applies the angular momentum raising operator

to the negative M-states generated by BLEND2.

(h) WORK begins the formation of isospin states, gen­

erating the coupled neutron-proton solutions in angular

momentum subspaces. The neutron-proton Hamiltonian interac­

tion is calculated and added to the energy solutions.

(i) COUPLE completes the mapping of angular momentum

subspaces onto isospin subspaces for both the metric and the

Hamiltonian. The final analysis programs are then loaded to

produce the separate contributions of 1- and 2-particle/hole

excitations to the final solutions.

(j) SCHMIT

SCHMITS2 applies the Schmidt orthonormalization pro­

cedure to the metric angular-momentum-isospin subspaces, gen­

erating transformation matrices to be applied to the Hamiltonian

matrices.

0RTH02 operates with the transformation matrices from

SCHMITS2, resulting in final energy matrices between orthonormal

states. Eigenfunction compositions and occupation number

expectations are also calculated.

177

Page 249: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1 7 8

S Y M E I G d i a g o n a l i z e s t h e f i n a l e n e r g y m a t r i c e s a n d g e n ­

e r a t e s o r t h o n o r m a l e i g e n f u n c t i o n s .

( k ) P L O T g e n e r a t e s c o m p a r a t i v e e n e r g y l e v e l d i a g r a m s .

Page 250: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

Figure 25. PHEXCIT Phase Overaly Structure. Phases, at

any given level, are loaded into core (temporally) in the

direction left to right.

Page 251: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

P H E X C I T P H A S E OVERLAY S T R U C T U R E

Page 252: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

DIMENSION NCMAXI8,l>.NUC8.lt.MCODE(12>,ISKATR(142).KRSPNDCIO),NJC15), STATE! 10),<OUNTR(8. 10,1), ITYPE! 142,1) .ADJUST (2) DIMENSION PRD3LMI20), OCCNUM!12,10)COMMON/LINE/INDEX!10,10,1)CDMMDN/S<ALAR/CDED(15,15),COVI2,55,8),COOI2,142,8),YC2,15,55).BINO.MI 15,15)CDMMON/NTRAXT/HFIBDYI12,12), B0Y21(405),B0Y22(325),30Y23!171).B3Y24I55), 8DY25 110) ,BDY26II) , B0Y2711),B0Y28( I ) CDMMDN/INTEOR/NJTRON«PRDrDN,N'JCLON,MDOUL»JMAXM« JMAXP, JHAX , NSPS,1 JID,LENTHN,LENTHP,LENGTH,NUMJN,NUMJP,NUMJ,MAXIN,2 MAXIP,NUMJHF,K0NTRL(5), MATRON, NSPSPl, 1 OF I NOlogical*i iskatrINTEGER PROTON,OOUBLDDJ3LE PRECISION COED,BI MOM, COVINTEGER*2 NJ.NCMAX.NU,MCODE,I NOE X,XRSPNO, STATE, I TYPEDOES THIS HAVE TO BE REDEFINED******--------- ♦»*+♦♦♦++*DEFINE FILE 2 2100,360,E.IOFIND

NOTE - BECAJSE OF THE TREATMENT OF (POINT) FOR STORAGE. THE PROGRAM WILL NOT WORK FOR KONTRLI1)“2** THIS PROGRAM ONLY WORKS ON EVEN-EVEN, N«Z NUCLEI* SINGLE PARTICLE STATES MUST BE ARRANGED WITH POSITIVE M BEFORE* CORRESPONDING NEGATIVE M STATES4♦KDNTRLII) EXPLANATION* 1 1-SOLVE ONLY ONE PRD3LEH 2-SOLVE 2 PROBLEMS* 2 O-PROJECT FROM STATES ONLY 1-PART ICLE-HOLE EXCITATIONS4 2-BOTH OF THE ABOVE» 3- O-SAME 1 -BODY OPERATOR FOR N ANO P 1-01FFERENT 1-BODY OPERATORS* 4 8-THIS IS A PARTICLE PROBLEM 1-HOLE PROBLEM* 5 O-THIS IS A NEUTRON/PROTON PROBLEM 1-NEUTRON PROBLEM♦DATA INPJT ON UNIT 5 UNLESS OTHERWISE SPECIFIED* IS<IP - NJM3ER OF CASES TO BE SKIPPED ON INPUT TAPE* PR03LM* I XONTRLII) ONTRL(2) <DNTRL(3)' ONTRL(4) X0NTRLC5)* 2 NEJT RONS, PROTONS, JMAXN, JMAXP, NSPS* 3 MCODE* 4 NJ - NE J T RON MULTIPLICITIES* 5 HF130Y - NEUTRONS* 6 NM* 7 M/ALJE, B0Y21,BDY22,...« .8 HFJPLS* --------- --------------- KONTRL11) =2--------* 9 NJ - PR3T0N MULTIPLICITIES•10 HF133Y - PROTONS (IF 01FFERENT FROM NEUTRONS)•11 NM FOR INTERACTION*12 MVALJE,30Y21,BDY22,...F0R INTERACTION* N'JMP AG•

UNIT 4 UNIT 4 UNIT 4 UNIT 4UNIT 4UNI T 4 UNIT 4

DO 5000 IJKL"1,10 REWIND 4CALL LOAD READR RE AD(5,1001)1 SKIP CALL READER!ISKIP) READ(5,1000)PR03LH 1000 FORMAM20A4)

WRI TE(6,1002)PROBLM 1002 FORMAT!1H1.20X.20A4)READ(5,1001KONTRL 1001 FORMAT(BI3)RE AO I 5,1001)NUT RON,PROTON,JMAXN,JMAXP,NSPS,JTONSPS?l=NSPS+NSPS+lAOJJS1(1)=0.4DJJST(2)=0.CALL LOAO REG I NRCALL BEGIN!NJ.NCMAX.NU.NCODE,ISXATR. XOUNTR, AOJUST,ITYPE, DOUBLI IF(<0NTRL(51.NE.1)G0 TO ISL = 000 1 L1=1,NUMJHF 00 I L2=L1,NUMJHF L*L*lDO 1 J-l.JMAX I Y(l,J,L)=COV(l,L,J). CALL LOAO WORKCALL SCHMITIY.AST.NJ.NUMJHF,NUM3ER,IND.INOEXl.l.JMAX)MAXIN0=I NUMBER*!NUMBER*!))/2 00 10 L=1,MAXIND00 10 J=1,JMAX10 Y(1,J,L)=C0V<2,L,J»1 ISPIN = 1 GO TO 18

C 15 NUCLON»NUTRON*PROTON M0DJL=M30(NIJCL0N,2) .JMAX=JMAXN+JMAXP-1c II SPIN"I(K0NTRLC21+11/21*2*1 IFCONTRLC 3) .EO.O)ADJUST! 1)»2.*A0JUSI(1)CALL LOAD WORKCALL WORKER(NCMAX,NJ.MCOOE.NJ,11SPIN,KOJNTR,ADJUST!2 ) , I TYPE, KRSPNO.SIATE.OOUBL,OCCNUM)C IB CONTINUEADJJS TI 1)"ADJUST I1)*ADJJST(2)CALL LOAO COUPLECALL COJPLEI11S>IN,Y,DOJ3L.XRSPNO,STATE,INDEX,NJ,ADJUST,PROBLM, OCCNUM)PAUSE PAUSE SOOO CONTINUEC STOPEND

179

Page 253: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SJBROJTINE HFZBOYCM.SIGN)CQMM3v/JPLUSR/HFJPLS(12.12),M03JLOI12) SO SHELLCOMM3N/3LOC</HV41UE(28>,NM16),IPR0D(24),MVALJI6,12,12)C0MM3N/3L0C<2/INI»M1,IN2.M2»IN3»M3»IN4,N4,MM»LCOMMON/INTEGR/NJTRON.PR3T3N,NUCLON,M30UL, JMAXV, JMAXP,JMAX,NSPS,1 • JT3,LSNTHN»LENTHP,LE NGTH «NUMJN» NJMJP»NUMJ*HAXIN*2 HAXIP»NUMJHF»<0NTRL(5)«MATR0N»NSPSP1»10FIND 03J3LE PRECISION HFJPLSINTEGER*2 MVALUE.N.M, IPR30.MVALU,MODULOH = MM N I = I N 1 N2=IN2 N3=IN3 N4=IN4IFIM.SE.1IG3 TO 3 M = 2 - M<< = ( IABSlMl)MABSIM2)fIABSIM3IMABSCH4l>/2 IF(M33KK,2).EQ.l )SIGN*-S!GNN L * MOOJL 0 ( N1)N2=M0DJl0(N2>N3*M30JLO(N3)N4 = M30JL 31N4)3 NUM3U = MVALU(M,Nl,N2)NJM3R2=MVALU(M,N3,N4)MAXI M = NM ( M)L1= MIN3< NUMBRl,NUMBR2)-l L2=MAX3(NUHBRl,NUMBR2)L=M4XIM*LI*L2-(L1*(L1*1))/2REIJRN End

SJBROUTINE S3LVEIC0T)DIMENSION C3TII)COMMON/SKAL AR/C3E0115.15),C3V12,55,B),COO(2.142,8),YI2,15,55),8 INOMt15,15)COMM3N/INTESR/NJTRON,PROTON, NUCLON,M3DUL,JMAXV,JMAXP,JMAX,NSPS,1 JTOtLENTHN*LENTMP»LENSrH,NUMJN*NJMJP»NUMJ«MAXlN*2 K4XIP,NUMJHF,<0NTRL(5).MATR0N,NSPSP1,I0F!ND D3J3LE PRECISION COED,8 IN3M, COT, TEMP, COVJ*JMAXU DO 4 1*1,JMAX LAHB3A*J J = J-lTEMP.COriJ)IF(I. EO.1)GO TO 403 3 JPRIME*LAMBDA,JMAX3 TEMP* TEMP-C3E0IJ,JPRIME)*COTCJPR1ME)4 COT!J)=TEMP/COEO(J*J)RETURNEND

SJBR3JTINE LOCATE I SIGN,XUK.LE3,NUCLON,MATRON) DIMENSION <U<(1),HU<(10)COMM3N/LDKAT/IBICOI12,6),LOXATE I 925,I ) INTESER*2 LOXATES13N* 1.DO 23 N*1,NUCLON

2 3 MU<(N)*KU<(N)1 = 132 IFIMJXIIl-MUXI1*1)133,34,3633 1=1+1IFI I-NUCL0N)32,21,21 36 N = M’J< 11)MUXII)=MUX(1+1)MUX(I+1)*N SISN*-SISN ■ IFt I.EO.DGO TO 33 1 = 1-1 GO TO 3234 SISN*0.RETURN

21 IFIMATRON.EQ.OIRETURN 1 = 1D3 1 N=1, NUCLON L-MJXIN)1 I=I+IBICO(L,N)LE3*L0.<ATE(I, MATRON)RETURNENDSJBR3UTINE C302L(XU<, I, J, NUCLON) DIMENSION KUKII) COMMON/STATES/NOOI 533,1) C0MM0N/C0DE/X0DERI6*12)NN=NJCL3N NEMP* NOOII,J)NNN=NNDO 1 N=l,NNH = NEHP/OOER(NNN,1)KUK!NNN)=MNEMP = NE MP-XOOERINNN, M)1 NNN= NNN-1RETURNENDSJBR0JT1NE TRIOJT(A.N)DIMENSION All)1 = 1DO 1 11=1,N LOW* ILIMIT=L0W*I1-1 I-LIMITM 1 WRITE!4 ,1000)(A(J),J=LOW,LIMIT) 3 FORMAT!IX,10F10.5)RETURNENO

)

180

Page 254: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

o o o o

o x n -<o c: o m *n m /4 w: o - j:

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► - tt— X •

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n o o v*U U « Lx x x o> x x m u lj x uX X V» <-m c <D 1/1 m Lb A* 73 D -Q

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« o O X «- x x u cr- w c. Xuj>h l *ti A3 1/1* X Ux u h l AX > Xm — « 73 *o »— <J>o X ■n«• *o r" a r- — m—i «. x * m x i/i* (iJO VLJ X x • —•Xa r~ o c -* *o ►- C OX LOc x x /w rv« JO• • r u 4 u * H •X < u X * -t *—*■» Xc m n r“ lj rv• c11 11 • m x - x*r“ A X « « (V XO C O -1 Z Xo oX >o x x c u u u« -i v n o m oX j/ ♦ r- c « m« p r o p K «—9 m x o w Xm ui4« - • rX —' L> X ►-X oU • -1 U N C IX X o —X;» * c-t X r-50 C ♦ oO X u •**2 L 1« X »X * xVI X X*© C •VI X t»U X•- •© >« « Xx *oo c«n X <-•«c.xz « >O X x> •X zM l/iz *o4 V*

181

Page 255: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SJ8R3JTINE BEG!N(NJ,NCMAX,MU»HC3DE, ISKATR,KOJNTR,ADJUST, ITYPE.DOUBLE)DIMENSION NJ(I),MCOOEII),ISXATRI1),A0JUST(2)01 MENS 13N NCMAX(8,l),NU(B,l),H(142,10),ITYPEC142,1>,VECT0RC533>,X3UNTRI8,10,1)C3MM3N/LINEZ INDEX I 13,10,1)C0MMON/C3DE/<QDER(6,12) SO SHELLCOMMON/JPLUSR/HFJPLS!12,12),HODULO(12> ■ SO SHELLC3MM3N/ I NTEGR/N JT RON , ? R 0 T ON , NUC LO.N, M3DUL , JMAXN, JHAXP, JHAX.NSPS,1 J r0, LEnthn. lenthp,LENGTH,numjn, njmjp, numj, max in,2 MAXIP,NDMJHF,<0NTRL<5),MArR3N,NSPSPl,I0FIN0 LOGICAL*! ISRATRINTEGER PROTON.OOUDLE E3JIVAl = NC£INUM3ER.ONTRL<l) )D0J3LE PRECISION HFJPLS, VECTOR, HINIEGER*2 NJ.NCMAX.NJ.MCOOE,INOEX, M3DUL3, 1 TYPEI3FInD=1 NJCLON=NjrRON JMAX = JMAXN D3J31t =3 REWIND 8DO 50 MATR0N*1»NUMBER 1F<MATR3N.£3.2)33 TO 10MCOOE IS TWICE THE ANGULAR MOMENTUM PROJECTION OF EACH OF THE SINGLE****** PARTICLE STATES *REAOI5,10011 IMC30EII) , I*l,NSPS) *MOOJL = MOD(NUCL ON,2)ODER IS JSED FOR COOING AN3 DECODING STATES (SEE SUBROUTINESL2COO ANO CDD2L)XODE = 1NN=MAX3INJTR3N,PROTON)- NN=MIN0<NN,61 00 2 N=l,NN DO 3 1=1,NSPS 3 K00ERIN,M)=<3DE*H 2 <OOE=<OOER(N,NSPS)*<ODEMOOJL0 ARE FUNCTIONS OF THE SINGLE PARTICLE STATE NUMBERS,JSEO TO CONVERT NEGATIVE M STATES T3 POSITIVE M STATES ANO VICE VERSA (SEE SUBROUTINES HF233Y ANO JMlNUS) no 9 N=1,NSPS,2 M33JL3!Nl=N*1 9 MOOJLO(NH)*NNJ IS THE NUMBER OF STATES WITH A GIVEN TOTAL ANGULAR MOMENTUM 13 REA3(5,1331MNJ(J),J = l,JMAX)1301 F 3.RM A T ( 2 4 I 3 )NCMAX IS THE NUMBER 3F DIFFERENT STATES WITH A GIVEN TOTAL ANGULARM3MENTDM PR3JEC11 ON <=NJ(JMAX)NCMAX(JMAX,MATRON)**L E N31H= X JPRIME=JMAX-1 D3 I J=2,JMAXK=NCMAX!JPR I ME*I,MATRON)*NJ(JPRIME)NCMAXt JPRIME,MATRON)*K length=length*x I JPRlME=JPRIME-lNJMJ=NCMAX<1,MATRON)CALL LOAD PRPARECALL PR5PARINCMAX( I,MATRON),NU(1,MATRON),MC33E.X0UNIR,

ITYPEI1,MATRON),D3U3LE)1*000 4 Il*l,NUMJHF DO 5 12*11,NUMJ.MF 1*1*1INOEXTII,I2,MATR3NI*I 6 INDEX(I2,I1,MATR0N)=I IF(NJMBER.E0.2)G3 T3 U WRITE(6,1032)NUMJHF1332 FORMAT!16H3PR0JECTI3N FR3MI2,24M NEUTRON (PROTON) STATES)GO TO 711 IF(MATR0N.EQ.2IG3 TO 12 WRITE(6,1033INUMJHF1333 FORMAT!16H0PR0JECTION FR3MI2.15M NEUTRON STATES)GO TO 712 WRITE 16, 1035JNUMJHF^1335 FORMAT! 15H0PROJECTION FR3M,I2,14H PROTON STATES)

T CONTINUECALL LOAD HAMLTNCALL HAMLrN(H,MC30E,ITYPE(l,MATR3N),I SKATR,A3JUST)• REWIND 1IFIMAIRON.EO.DRE AD I4)((HFJPLS(I,J),J»1,NSPS),I-l, NSPS)1 PR I ME* 100 4 1=1,NDMJIF(I TYPE I I.MATRON).EQ.0)30 TO 4 00 8 K=l,LENGTH B VECTOR!<)=0.D0 VECTOR! 11 = 1.00CALL JPLUSIVECTOR,NU!I,MATRON),MCOOE,2)WRITE!1)(VECTORIX),X=l,LENGTH)IFIIPRIME.EO.NUMJHFIGO TO 45 IPRIME=IPRIHE*1 4 CONTINUE

C 45 IFIMATR3N.E0.2IG3 T3 40 MAX IN = NJMJHF NUMJN=NJMJlenmn*length43 CONTINJECALL LOAD FINEECALL FINISHIH,NCMAXTl,MATRON),NJ(1,MATRON),MC33E,!TYPE(1,MATRON), ISKATR)IFI<3NTRL(5).E3.1)RETURN NUCL ON = P R3 TON 50 JMAX*JMAXP MAXIP=NJMJHF NJMJP=NJMJ LENTHP=LENGTH RETURN ENO

Page 256: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

o u

SJBR3JTINE PREP4RINCMAX,NU,MC3DE,K0U.NTR,ITYP6,30UBLE)DIMENSION NCM4X<1),NU(1),MC30E<1),K0U,NT(21,ITYPE(1>,MUX(6),XUX(&) DIMENSION POINT 15333,2),X3UNTR<3.10,1)COMM ON/S TATES/NOD I 533,1)C0MN0N/i.3<AT/ IB I GO! 12,6),LOXATE(925,1)C3MM3V/JPLUSR/HFJPLSI12,12).MODULO!12)C3MMON/INTE3R/NjrRON,PROT3N»NUCLON,M3DUL»JM4XN»JMAXP»JMAX»NSPS»1 UI3,LENTHN,LENTHP,LEN3TH,NUMJM,NUMJP,NUMJ,MAXIN,2 MAXIP.NUMJHF.XONTRLIS), MATRON,NSPSPl, I OF I NO D3J3L E PRECISION HFJPLS EQU!YAL = NCEH3LES,K3NTRL(2))INTEGER HOLE,AUORES,PR3I3N,DOUBLE,HOLES INTEGER*2 NCMAX,NU,MG3DS,P3INT, L0X4TE, MODULO,I TYPEMINl*MlN3< NUTRON,PRO ION)N P I 3 M I N I UMAXI3MAXO(NUTRON,PROTON)MATRIN32«MATR0N-2 IFIMATR3N.E3.2IGO TO 2IBIG3 ARE BINOMIAL COEFFICIENTS USED TO LOCATE STATES IN THE LISTNOD (SEE SUBROUTINE LOCATE)03 20 I-l.NSPS <3I-1 L*XIBIC3(I,1)*L 00 23 J=2,MAXI < = <-1IF !J.GT.1-1IG0 TO 22 L*(LM)/J IBI CO I I * U)*L GO 10 23

22 -!8!C3(I,J)*023 GONTINJEc 2 NJMJHF°l N J I I I O00 133 M»2,JMAX MM 3 M“ INJIM)=NJ(MM)♦NCMAX(MM)103 NCMAX(MM)=3NCM4XI JMAXIOC 00 1 N31,NUGLON 1 XJ<(N).»N KU<(1)-0 IIY=*EI l ) - lC GREAT E A LIST (NOD) OF STATES HAVING ANGULAR M3MENTUH PROJECTIONC ■ GREATER THAN OR EQUAL TO ZERO. STORE THEM 3Y M-OROER. THE ARRAYC L0<ATE GIVES THE CORRES»ONOENCE BETWEEN H-OROERIN3 AND THE ORDERC OF PRODUCTION

LX*300 10 <31,LENGTH3 00 9 N3I. NUGLON [TEST3XU<(N»l)-l IF<N.E3.NUCL3N)ITEST*NSPS 1FKJ<(N).E3.ITEST)S0 TO 9 XU<(N)=<J<(N)Hl IFIN.EO.1IGO TO 5M=N-1DO 3 Nl*l,M B XU<IN1)3 NI

C 5 NSI3*0DO 4 Nl*1,NUCLON M*XU<(N1)4 NSIG*NSIG»HCODE(M)LX=LX*1IFINSIG.LT.MDDUDGO TO 3 NS IG* NS IG/2MC IX»NGMAX(NSIG)+1 NGMAXINSIG)*IX MG = NU(NSIG) MX

GALL L2G00IXJX, NOD I MG,MATRON) , NUCLON)LOXATEILX.MATRONloMG IFINSIG.NE.1.0R.MG.E3.D30 TO 10 IFHOLES.EQ.OIGO TO 205CC _ FIND THE PARTICLE-HOLE STATESC IT IS ASSUMED THAT IF NUTR3N .NE. PROTON THEN THERE IS A NEUTRON EXCESSHOLE 3 0 NNM= 1DO 231 NM*I, NUCL3N iF(<JX(NNM).EQ.NM)G3 TO 202 IFIHJLE.E0.2IG0 TO 205 MISING«NM HOLE3 HOL EM GO T3 231202 NNM=NNMH 201 CONTINUEC GO TO (208,209),HOLE C TYPE THE IP-1H STATES208 NJ.MJHF = NUMJHFM IFIMISING.GT.MINDGO TO 203 IF(XJX(N'JCLON).3T.NJTRON)30 TO 204203 I TYPE I MG)*2 GO TO 13234 ITYPE(MG)»3 GO TO 13CC TYPE THE 2P-2H STATES209 NEMRl-XJXINUCLON-l)■NEMP2*XU< I NUGLON)IF(MG0r)c(NEMP2).NE.MC00E(HISING))S0 TO 205 IF(NSMP2.NE.NEMPl+l.DR.M0DCNEMP2,2).NE.0)6O TO 205 NUMJHF3NUMJHF+1 11YPEI M3)=4IF(M4rRDN.E0.l)D0UBLE=00UBLE*l GO 10 13235 ITYPE(MG)*0 GO TO 139 CONTINUE 10 CONTINUEC FINO THE PARTICLE-HOLE STATES HAVING ANY ANGULAR MOMENTUM PROJECTIONC ANO XEEP TRACX OF WHICH STATES THEY GOME FROM. THESE ARE REQUIAEO-iC IN SUBROUTINE BLENO COC AODRES 3 (LENGTH,NUMJHF) UJXX20 ADORE S* 3 ICOUNIO03 336 <2*1 ,NUMJ

Page 257: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

!FUTYPE(<2).EQ.0)G0 TO 306 K<2«XX2*lCALL C002LIHJK, K2, MATRON,NUCLON)<1 = 003 304 M=1,JMAX <0JNT(1)=3 XDJNT (21=0 NCM=NCMAXt M)03 300 1=1,NCM X I » < 1 » IADORES-ADDRESHCALL CD021IXU<,<1,MATRON,NUCLON)00 300 ITRIY=1,2 IIRY=ITRIY»MATRIN lFIITRIY.EO.DGD TO 307 IFtM.EO.llGO TO 300 00 3DB N=l,NUCLON NM=<J<(N)303 <J<(N)=m30UL0(NM)307 HOLE = 0DO 301 N= 1,NUCLON 00' 302 NM=1.NUCLON IFKJ<(N).EQ.MUX<NM)IGO TO 301 302 CONTINUEIFHOLE.EQ.11GO TO 305HOLE = 1 ^301 CONTINJE<*<OJNT(ITRIYDI XOJNTtIT RIYI=K POINTIAOORES.ITRYHR GO TO 300 335 POINT(ADORES,I T R Y )» 0 300 ICOJNT=MAXO(ICOUNT,<1304 XOJNTRIM,<<2,MATRDN)=HAXO(<OUNT(1),K0UNTI2))306 CONTINUE

c WRITEIS,1000)ICOUNT 1000 F0RMATI23M0THERE ARE A MAXIMUM 3FI3.38H PARTICLE-HOLE STATES HAVIN.G A GIVEN M)C IRITHDMATRIN IRIT2=IRlTl»l 00 310 M = 1,J MAX NCM*N3MAX(M)N'JM = NU I M)DO 310 .1 = 1, NUM J HF LOW- I I-D•LENGTH*NUMFl LIMIT=L0H*NCM-1 310 WRITEI8X (POINT(J,K),J = LOM,LIMIT),K=tRITl,IRIT2) 'RETURNEND

SUBROUTINE L2C0D(KU<,K0DE,NUCLON) DIMENSION KUX( 1 ) , KODE(2) COMMON/COOE/XOOER(6,12)

c NEMP»0 .NN=NJCLON DO 1 N=1,NN M=<J<(N)NEMP=NEMP*KODER(N,M)1 CONTINUE KDDEt1) = NEMP

cRETURNEND

481

Page 258: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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SJBR3JTINE HAMLTN(H,MCODE»ITYPE»ISKATR»AOJUST)DIMENSION H(1)»MC3DE(1)»ITYPE!1)*ISX4TRI1)«ADJUST(2)»KUK(6) ,IBUFR(28)CDMM3N/NTRAXT/HF1BDY!12,12), B0Y2I(405),BDY22I325),• 30Y2 3!171),B3Y24!55), BDY25(101,B0Y26<I ) , B0Y27(1 ) ,BDY28!1) COMM3N/3lOC</MVALUE( 28) ,NM(6), I PROD! 24) ,MVALUti,12.12) CDMM3n/ 3LOC<2/NM1,MM1,NN2,MM2,M1SAVE.M1,M2S4VE,M2,M,LL C3MM3N/INTE3R/N'JTR0N,PR3TDN, NUCL3N t M3DUL»JM4XN»JMAXP»JMAX»NSP$»1 JI3,LENTHN,LENTHP,LEN3TH,NUMJN,NJMJP,NJMJ,MAXIN,2 MAXIP,NUMJHF,<ONTRl(5),M4TRON,NSPSPl,IDFl.ND INTE3ER AODRES.HDLEL0G!CAL*l ISXATR E3UIVALENCEMDLE,XONTRL(4) )DOJ3LE PRECISION H , T E.MP , TBME INTS3ER*2 MVALJE,NM,[PR33,MVAIU,M:03E.ITYPEc IF tMATR3N.E3.1.0R.X3NTRL( 3).EQ.l)READ!4)((HF1 BOY 11, J) , J = 1, NSPS),1=1,NSPS)IFIMATR3N.E0.2I33 TO 99 NSPSP'NSPSPL-1 II=NSPS?1 03 98 I = L, NSPSP IPR33( I) = 1 I 98 11=11*NSPSP1CC INM) IS THE NUM3ER 3F DIFFERENT 2-B30Y STATES FOR A 31 YEN 2-PARTICLEC M valueREAD!4 ) ( IBUFR(H),M=l,JT3)33 52 M = 1, J T 3 62 NMIM)=I3JFRIM)00 133 M=1,JTOMAXIM=NM(M)IFIMAXIM.E3.3I33 TO 103REAOI4)I!BUFR(NJMBER)«NJNBER“1«MAXIM)33 64 NJMBER=l,MAXIM 64 MVALJE(NJMBER)=IBUFRINUMBER)03 53 NJMBER=1,MAXIM I= MV A LU E(NUMBER)1 l = l/NSPSPl12 = 1-1PR30II 1)53 MVALJIM,I 1 , I2) = NUMB£RL=IMAXIM*1 MAX IM♦1))/2GO 73 I 11, 12,13,14,15,16,17,18),M11 REA3!4)(bOY21(X),K=1,L)33 13 13312 REA3!4)130Y22IX),X=1,L)33 T 3 13313 RE A3(4)(B0Y23IX),K = 1,L)33 T 3 13314 RE A3(4)I30Y24IX),X«1,L)30 TO 13315 REA3!4)(BDY25IX),K=1,L)33 T 3 13015 RE A3(4)(3DY26IX),X = 1,L)33 T3 13317 READ!4)1RDY27IXI,X=1,L)33 T3 133

IB READ! 4)(3DY28(X),K = 1,L)133 CONTINUENOTE THAT (ISXATR) IS DEFINED INVERSELY, I.E., HOSE S T A T E S W H I C H ARE SCATTERED TO HAVE ELEMENTS (.FALSE.)

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99 00 131 I-1 ,NUMJ 131 ISXATRII)■•TRUE.OPERATE ON THE HARTREE-FOCK STATE ANO, IF OESIRED, ON THE PARTICLE- HOLE STATES WITH ANGULAR MOMENTUM PROJECTION ZERO 11 = 1ADDRES=3 03 22 1=1,NUMJ IF( t T YPE(1 ) .EQ.D)GO TO 22 <«ADDRES DO I J = 1,NUMJ K= <♦ I 1 H(X)=3.30CALL C002LIXUX,I, HATRON,NUCLON)CHOOSE THE FIRST PARTICLE AND SCATTER IT 03 21 Nl=l,NUCLON ‘ N1P1»NI*LM1SAVE=<J<(N1I ML=MCODc(MLSAVE)DO 90 NN1=1,NSPS mM1=MC0JE(NNI)XU<(N1)=NN1IFIN1.E3.NUCLON.OR.NNi. EO.NSPS)30 T3 24 NN1P1=NN1*1CHOOSE THE SECOND PARTICLE AND SCATTER IT CF3R THE 2-BODY OPERATOR) DO 23 N2=NIPI,NUCLON"M2S A V E = X'JX I N2 )M2=MC03E(M2SAVE)HPRIME=M1+M2 M=M»RIME/2*1 DO 13 NN2=NNLP1,NSPS MM2 = MC03E(NN2)IF(M?RIME.NE.MM1*HM2)G0 TO 10 XU<(N2)=NN2LOCATE THE NEW STATE IN THE LIST, 03TAIN ITS 2-300Y MATRIX ELEMENT, AND ADO ITS CONTRIBUTION TO THE HAMILTONIAN CALL LOCATE!SIGN, XUX, LEX, NUCLON, MATRON)IF(SIGN.E3.3.)30 TO 10 CALL HF2B0Y!MRETRN.SIGN)GO TO ( 31,32,33,34,35,36,37,38),MRETRN31 TBME=BDY21(LL)GO 73 4332 TRME = B0Y22!LL)GO T3 4333 TBME=BOY23(LL)GO TO 4334 TBMC=BDY24(LL)GO T 3 4335 TBME=BDY25(LL)30 TO 4336 TBML=B0Y26(LL)GO TO 43 |_j37 TBME=B0Y27(LL) COGO T3 43 UR3B THME=B0Y28(ll>40 X=ADDRES*LEXIF(SIGN.EQ.-1.)TBME*-TBME ISX4TR(LEXI=.FALSE.HI XI =H( < ) ♦ TBME

Page 259: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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Page 260: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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SJBROJTINE COMBIN(H»NCMAX,NU»MCODE»ITYPE»IS<ArR)DIMENSION VECTR1(5331.VECTR2I533) ,C0T(8) ,COT TI 3 > ,RITE UDO) DIMENSION HI 1) .NCMAXIII,NJ<1) , MCDDE(1>,I TYPE(I ) , ISKATRI1> COMMON/SXALAR/COED!15,15),COV!2,55,8) ,COD(2,142,81 ,Y(2,15,55) ,B I NOMI15,15)COMMON/INTE3R/NUTR0N.PROT ON.NUCLON,M3DUL.JMAXN,JMAXP, JMAX,NSPS,1 JT3,LENTHN.LENTHP,LENGTH,NUMJN.NUMJP,NUMJ,MAXIN,2 MAX IP,NUMJHF,<ONTRL(SI(MATRON,NSPSP1,I0FINDinteger adoreslogical*i isxatrINTEGER*2 NCMAX,NU,MC3DE,irrPED0J9LE PRECISION COED,3 INOM, COT, COV,SCALAR, VECTRl, VECTRZ ,HC IFIXONTRLI ll.EQ.21GO TO 40 WRITE(6,1031)1001 FORMATI27HONEUTRON AND PROTON METRICS)GO 10 4240 IFIMATR0N.E0.2)G0 TO 41 WRITE I 5, 1002)1002 FORMAT! 15H0NEUTR0N. METRICS)GO 1.0 4 241 „RITE(6,1004)1034 FORMAT!15H3PROT0N METRICS)COVIN,-,j) CONTAINS THE AMPLITUDES OF THE NORMALIZATION AND ENERGY MATRICES FOR BOTH NEUTRON AND PROTON STATES WITH ANGULAR MOMENTUM PROJECTION ZERO FOR EACH VALUE OF TOTAL ANGULAR MOMENTUM J ( I )-NEJT RON NORMALIZATION, 121-NEUTRON ENERGY,(31-PR0I0N NORMALIZATION, (41-PROTON ENERGY42 RE «I NO 1 MANAGE*MATR3N*MATR0N LI MI I 1*1MAXI NO*(NUMJHFM NUHJHF + 11)/2 DO 5 IJ X* 1, 2DO 1 <=1,NUMJHF ll*<-numjhf IFllJR.EO.l)GO TO 47 REWIND I LIMIT1 = <47 DO 45 <1=1,LIMIT145 REAO!l)(VECTR2(L),L*l,LENGTH)IF(IJK.E0.1)llMIT2«<

' REWIND 1 00 11 I»I,LIMIT2 IF!IJX.E3.11G0 TO 16 . IF!IS<A!R(I) ICO TO 11 IF( I TYPE I I ) .EO.OIGO TO 20 16 REA0(1)(VECTR1(L),L-1,LENGTH)GO TO 45 20 00 13 L=l,LENGTH ID VECTR1Il)*0.D0 VECTRl!11*1.DOCALL JPLJS(VECTR1,NU,MC30E,2) i46 NJMX«0 00 32 M=I, JMAX NCMX = NCMAX IM1 SCALAR*3.00 03 2 1*1,NCMX NJMX = N'JMX»1

2 S C A L A R » S C A L A R + V E C T R 1 I N U M X 1 * V E C T R 2 ( N U M X )32 : 0 T ( M ) « S C A L A RC

C A L L S O L V E (C O T )I F U J X . E 3 . 1 I G 0 TO 13

C C O D ! L , J ) C O N T A I N S THE S E P A R A T E C O N T R I 3 U T I O N S OF E A C H T E R MC H A M I L T O N A l A N TO THE E N E R G Y M A T R I C E S OF C O VC II) - P R O D U C T S W I T H C O N T R I B U T I O N S F R O M S T A T E S W I T H M ■ 0

D O 35 J* l . J M A X 35 C O D ! 1 , I , J ) = C O r < J )

CA D O R E S * I - N U M J LL * X - N U M J H F D O 31 L * 1 , X L L = L L * N J M J H F - L + I A D O R E S * A O O R E S + N U M J TEMPO*!!! A D O R E S )- D O 33 J * I , J M A X

33 C O V ! M A N A G E i L L , J ) * C O V ( M A N A G E , L L , J ) » C O T ( J ) * T E M P O 31 C O N T I N U E

G O TO 11C13 L L * L L + N U M J H F - I + 1

D O 34 J * 1 , J M A X3 4 C O V ! M A N A G E , L L , J ) » C O T I J )11 C O N T I N U EI IF IJX.E3.2 WRITE 2 IOFIND,1000 COO LM1, LM2,LM3 ,LM1 1,2

1 , N U M J ,LM3 l.JMAX 1030 FORMAT!VDA4)C4 9 D O 43 J * 1 , J M A X

J P R I M E * J - lL * 0D O 44 L l = l , N U M J H F D O 44 L 2* 1 , L 1 L = L + lL M * ( L 2 - 1 ) * N U M J H F + L I - I L 2 * ( L 2 - l ) ) / 2

44 R I T E ( L ) * C O V ( M A N A G E , L M , J )5 0 W R i r E ( 6 , 1 0 0 3 )JPRIME

1 0 3 3 F O R M A T ! 3 H 3 J = I 2 )43 C A L L r R I O U T I R I T E , N U M J H F )

IF! I J < . E 3 . 2 ) R E T U R NCW R I !E ( 6 ,1005)

1 3 3 5 F O R M A T ! 1 H 1 , 5 X , 8 H E N E R G I E S )■MANAGE = M A N A G E + 1 0 0 1 0 0 l=1,MAXIND D O 1 0 3 J * 1 , J M A X

1 3 0 C O V ( M A N A G E , L , J ) » O . D OL I M I T 2 * N U M J

5 C O N T I N U E R E T U R N E N D

Page 261: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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SJBROUT I NE BLEND ( NCMAX,NU« MCODE )DIMENSION NCMAX(l),NU(l),MCODEIl)DIMENSION VECTR1(533),VECTR2(533),VECTR3(533),C3SI8)«COT 18),POINT!142,10,2)COMMON/SXALAR/COEDI15,15),CDVI2,55,8),C0D(2,142,B), VI2,15,55),BINOMI15,15)COMMON/INTEGR/NJTRON,PRO TON,NUCLON,MJDUL, JMAXN,JMAXP,JMAX.NSPS.1 JT0,LENTHN,LENTHP,LEN3TH,NUMJN,NUMJPfNUMJ,MAXIN,2 MAXIP»NUMJHF,<0NTRU5), MATRON,NSPSP1 , 1 OF I NO INTEGER ADORESLOGICAL MANAGEINTE3ER*2 NCMAX,NU.M30DE,POINT00J3LE PRECISION COED,31NOM, COT, COS, SCALRl, SC4LR2, XI, X2, COV, VECTR1.VECTR2.V6CTR3SELECT PARTICLE-HOLE STATES NOT HAVING ANGULAR MOMENTUM PROJECTION ZEROANO FIND THEIR CON T RIBU11 ONS COO(I,-,J) TO HE HAMILTONIAN MATRICES(1) - PROOJCTS WITH POSITIVE M 12) PROOUCTS WITH NEGATIVE MX<=2«MATR0N-1AKP t = <<♦1REWIND B00 52 L M2 - I»NUMJHF52 READ< 3)T( POINT(LM1,LM2,LM3I,LMl»l,NUMJI,LM3-1,2)00 70 M-2.JMAXMP1=M*1 MM1 = M-l NC.M- NCMAX I M)REWIND 100 53 LM2=1.NUMJHF53 RE AO IB)I IP0INT{LM1,LH2,LM3),LM1=1,NCM),LM3=1,2)00 70 <-1,NUMJHF• 90 54 1 = 1,NUMJ 00 54 J-l.JMAX COOI 1 , I , J >=0.54 COOI2 , I, J > = 0.»62 REAOt1){VECTR1(LK),LK"1,LENGTH)NJMX = NIJ(M)00 51 1 = 1 , NCM NJ.M< = NJMX»1DO SO L<=1,NUMJHF 50 I F I »0 INTI I ,LK,K<)+POINT< I , LK ,KKP1) .3T.0) GO TO 60 30 TO bL 50 00 53 L4-1,LENGTH VECTR2(l<)=0.0063 VECTR3.lLO-0.00 VECTR2INJMXI-1.00 VECTR3INJMX)=1.00CALL JPLUSIVECTR2,NU,MC00E,MP1I call JMINUSIVECTR3,NU,MC00E,NUMX,MM1|

71 M'J-JMAX J-MJ00 54 JJ-l.JMAX IFIJ.LT.M)GO TO 68 SCALRl-3.00SCALR2-0.00 . |SCALR2-3.NJM3=NJIMJ*l)*lIF < MJ.E3.JMAX)NJMB=LENGTH*1NCMX-NCMAXIMU)00 55 L-l.NCMX

SC AL R l-SCALRl+VECTRK NUMB )*VECTR2( NUMB)65 SCALR2-SCALR2FVECTR1(NUMB)*VECTR3(NUMB)IF( JJ.E3.D30 TO 69 LAMBOA-Jfl00 55 JPRIME-LAMBOA,JMAX Xl-COEOI .MU,JPRI ME)X2-0S0RT(C0ED(M,JPRIME))SCALRl-SCALRl-CDTIJPRIME)*XI/X266 SCALR2- SCALR2-COS(JPRIME I*Xl*X2 69 X1-C0ED(MU,J)X2=DS0RT(C0ED(M,J))COT!JI=SCALRl*X2/Xl COS!JI=SCALR2/(X2*X1)GO TO 67 , 6B COTIJl-O.OO C OS IJ >- 3 .DO67 COOI1 , I,J)=30T(J)C00(2,I,J)-C0SIJ)MJ-MJ-I64 J-J-lC 61 CONTINUE73 WRITE 2 I OF I NO,1000 COD LM1.LM2.LM3 ,LM1 1,2 ,LM2 l.NUMJ ,LM3. 1, J M AX1000 FORMA TI90A4)RETURNEND

NJMB-NUMB-1188

Page 262: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SJBR3JTINE JHINUS(VECT3R«NU,MC03E,I,MLOM)DIMENSION VECTOR!1),NUI11. MCODE<U , KUK110),MUX(13)C3MM3N/J9IUSR/HFJPLS(12?12)«M30UL0(12) SD SHELLCOMMON/INTE3R/NJTR0N,PR3T3N,NUCLON,M0DUL,JM4XN,JMAXP,JMAX,NSPS»1 • JT3,L5NrHN»LENTHP»LENjTH,NU.MJN,NUMJP,NUMJ,MAXIN,2 MAX IP.N'JMJHF, KONTRL (5), HA IRON, NSPSP1 , I OF I NO INTE3ER+2 NJ,MC33E,M3DUL003J3LE PRECISION HFJPLS, VECTOR, X, TEMPMPl-MLOW+103 II <<=l,MLOWIFKK.NE.IIGO T3 4L = I + 1NCM= 103 T 3 5

4 L = NJ(MP1+1I+l NC M = L-NJ(MP1I-I5 03 13 K=1,NCM L = l-1< = VEC TOR(L)• IF(X.E0.3.130 TO 10 CALL C032L(MUK,L,MATRON,NUCLON)03 3 N= 1,NUCLON M = M J < 1 N 1 3 KUON)=M3DUL0!M)CALL LOCATE!SIGNS. KUK, LEX,NUCLON,0)D3 1 N=l,NUCLON M = K JO N I HPRI-E-MUKIN)• MM=MC3DEtMl+2 03 2 NN=1,NSPS IF1MC3DEINN1.NE.NHI30 TD 2 KJK(N1=NN MJKINI = M3DUL01NN1 PH4S E = 1.CALL LOCATE!SIGN,XUX,LEX,NUCLON,MATRON)IF(S!GN.E3.0.)G3 TO 2 IF1S13N.NE.SIGNS)PHASE--1.IF ( U.LT.MLOWICALL LOCATEISIGN• MUX,LEX,NUCLON,MATRON)

3 TEM?=HFjPLS(NN,M)oxIF!9M4SE.E3.-l.>TEM>=-TEMP VECT3R(LEX 1=VECTOR!LEX)+TEMP 2 CONTINUEMJUNUMPRIME 1 <J<( MUM10 CONTINUE11 MPUMPl-1MANAGE-NJMJ+l 03 13 K=M4NAGE,LENGTH 43 VECTOR! 0=0.00CALL JPLJS(VECT3R,NU,HC0DE,2)RETURNENO ,

Page 263: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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SJBROJTINE WORKER!NCMAX,NU»MCOOE»NJ,11SPIN.XOJNTR,ADJUST,I TYPE, KRSPNO.STATE,30U8LE,OCCNUM)DIMENSION MC0DE(1),XRSPND(1)»XUX(12)»MUX(12)»4ST(1),NJ!1)»ST ATE!I)DIMENSION NCMAX(8, I),NUI 8 ,1).POINT!142,10,2),COT(15 ) . IBUFR!28),1 XOJNTRI 8, 13, I ). ITY>E ( 142,1) ,0CCNUM( 12,10) ,C0F (2,142, B) ,

2 corn IS) .COUPLE 110,10) ,C0UPEL(13,13)COMMON/LINE/I NOE XI10,10,1)COMMON/JPLUSR/HFJPLS!12,12),MOOJLO(12) S D S H E L LC3MM0N/310CX2/XXI,M1,XX2,M2,KX3,M3,KX4,M4,MSTAR,LLLCOMMON/3LOCX/MVALUE(28) ,NM( 6 ) , IPROD(24),MVALJ!5,12,12) S D S H E L LC0MM3N/NTRAXT/HF18DY(12,12), BOY2I(436),B3Y22(325),83X23(171),80Y24(55),BOY25I1D),BOY26II), B0YZ7(1 ) ,BDY2B!1) COMM3N/S<ALAR/COED(l5t l5),COV(2,55,U),COO(2,142,3),Y(2,I5,5S),81N0M115,15)COMMON/INTESR/NJTRON,PROION,NUCLON,MODUL,JMAXN,JMAXP, JMAX, NSPS,1 J10,LENrHN,LENTHP,LENGTH,NUMJN,NJMJP,NUMJ,MAXIN,2 MAX IP,NUMJMF,X0NTRL(5), MATRON,NSPSPI, I OF I NO INTEGER ADORES,PRO TON,81 OCXS,DOUBLEINTEGER‘2 NJ,NCM4X,NJ,MCOOE,POINT,XRSPNO,INOEX, I TYPE,. • MOOULO.MVALUE.NM,IPR30.MVALU,STATEOOJ3L E PRECISION HFJ>LS, C3E0,3 INOM,COT, COTT, X, XX1,XI, XX2, I , 1 1,1 YPRIMl,YPRIM2»XPRIMl,XPR[M2,TEMP,GIANT,ClANT1»BIN0,CUPL»CUPLI2 ,COEOS,SIGMA,SIGMAl,RATIO,YY1,YV2,;0UPEL,COUPLE,COV DATA LEFT/IH)/,l1NE/IH /.RIGHT/1H /.PLUS/1H /REWIND 3 MANAGE =0IF(XONTRL(5).EQ.3)AOJUST=AOJUST*2.JJJMAX=1LU0T=JM4XN*MAX1Nblo: xs=numjn*jmaxn*2IAOJOIFIMODI3LOCXS,90).NE.O)1400*1BL0:XS=3L0CXS/93»IADDMAXInD=<NUMJHFM NUMJrtFM ) )/2NSPSP=NSPSP1-1wRITE(6,1010)1010 FORMAT!17H1INTRINSIC STATES)GO TO 893(NM) IS T H E N U M B E R .OF 0 1 F F E R E N T 2 - B O D Y S T A T E S F O R A G I V E N 2 - P A R T I C L E * * * * * * M V A L U E . *

9 1 3 R E A O l 4 ) ( I B U F R I M J ) , M J * i , JTO)0 3 54 H J * I , j r O 54 NM(MJ)='IBUFR(MU)03 130 MU*I, J TO MAXI M*NM( .MU)IF(MAXIM.EQ.0)G3 TO 100READ! 4) ( I BUFR (XOUNT) , KOJNT*I, MAXIM)DO 53 XOJNT*!,MAXIM 53 MVALJE!XOUNT)=I3UFR(XOUNr>DO 200 <3UNT*I,MAXIM I=MVALUE(X3UNT)U*I/NSPSP1 12 = 1-1 PROD!11l-NSPS 203 MVALJIHj, I 1 , I2)=X0UNT LMMAXlM«tM4XlM»l>)/2 GO TO (11.12,13,14,15,16,17,18),MU11 REAOI4) (BDY21(<),X»1,L)GO TO 10012 REAOI4) (BDY22(K),K"1,L)

G O T O 1 0 013 R E A D ! 4) ( B D Y 2 3 I K ) ,X *1

G O TO 1 3 314 R E A D ! 4) (B 0 Y 2 4 ! < 1 , X * 1

G O TO 1 3 015 R E A D ! 4) ( B 0 Y 2 5 (X 1 , X * 1

G O 10 13 016 R E A D ! 41 (B 0 Y 2 6 ! X ) ,X *1

G O TO 10 017 R E A D ! 4) ( B D Y 2 7 ( K ) , K * 1

G O TO 10318 R E A O I 4) (B D Y 2 8 (X ) , X * 1

1 0 0 C O N T I N U EJ.MAXM = MI NO I J M A X N , J M A X P )J J J M A X = J M A X M J J M A X = J M A X H * J M A X M - 1

: ' h e r e t h e a d j u s t m e n t f o r h o l e s t a t e s i s c a l c u l a t e dI F ( X 0 N T R L ( 4 ) . E Q . 3 ) G 0 TO 8 9 0 DO 951 X X 1 * 1 , N S P S M l = M C O D E ( K K l >XX 3 = X X 1 H3 = MI0 0 951 K K 2 * 1 > N S P S M 2 = M C 0 D E ( K K 2 )X X 4 = X X 2 M 4 ° M 2M S T A R = I M 1 * M 2 ) / 2 * 1 S I C N * 1•C A L L H F 2 B D Y ( M R E T R N , S I G N )G O TO ( 9 5 1 , 9 6 2 , 9 6 3 , 9 6 4 , 9 6 5 , 9 6 6 , 9 6 7 , 9 6 8 ) , M R E T R N

96 1 T E M P = B D Y 2 l ( L L L )G O TO 9 5 5

9 6 2 T E M P = B 0 Y 2 2 ( L L L )G O TO 955

9 6 3 T E M ? = B D Y 2 3 ( L L L )G O TO 9 5 5

9 6 4 T E M P = B D Y 2 4 ( L L L )GO TO 95 5

9 6 5 T E M P * B 0 Y 2 5 ( L L L )G O TO 9 5 5

9 6 6 T E M P = B O Y 2 6 1 L L L )GO TO 95 5

9 6 7 T E M P * B D Y 2 7 I L L L )GO TO 9 5 5

9 6 8 T E M P = B 0 Y 2 8 ( L L L )9 5 5 I F ( S I G N . E Q . - 1 . ) T E M P * - T E M P

A O J J S T * A O J U S T * T E M PI F ( < X l . L E . N U T R O N ) A D J U S T * A D J U S T - T E M P I F ( X X 2 . L E . N U T R 0 N ) A 0 J U S T * A 0 J U S T - T E M P

951 C O N T I N U EW R I T E ( 6 , 1 0 0 0 )

1 0 0 0 F O R M A T (1 HI, 1X )

8 9 0 X K ° X O N T R L ( 1)KKKK=2*KK X * X X X X - 1 X X X = N U T R 0 N * 1

S E L E C T I N T R I N S I C N E J T R O N - P R O T O N C O M B I N A T I O N S F O R S C A L A R P R O D U C T S (RMS)X R 2 P N D = 2 * D O U 8 L E * 2 LI *3

190

Page 264: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

113*303 27 13*1,NUMJN 131*1 TYPE(13,1)IF(I3I.E0.0)G3 13 27 I I 3*I I 3+ 1IF(I3I.E3.4)G0 T3 27 CALL C302L(KUX,I3,1,NUTRON)NEMPl=XJX(NUTRON)C J J 3 = 0DO 25 J 3* 1,NUM JP J3J=ITYPE(J3.XX)IF(J3J.E3.0IG0 TO 26 JJ3*JJ3*lIF113I.E3.3.AND.J3J.NE.3)G0 TO 26 CALL C032LIXUXIXXX),J3,XX, PROTON)NEM?2=<JXINUCLON)IF( I3I+J3J.E3.6.AND.INEMP2.NE.NEHPl*l.OR,HOD(NEMP2 *21• NE.O))CO TO 25 IF(MANA35.EQ.O)<RSPND(LD1)=0 IF( I 3 I. E3.3)GO TO 872 GO TO (373,873,874,875),J3J872 ST'4TE(L1»1)=4 GO TO 933873 SrRTE(Ll»l>*l G3 T 3 933874 lFIM3DtNEM?2,2).EQ.3)G0 TO 26 STATEILIM>=2GO TO 933875 STATEILl+l1*3 IFIMANACE.E3.0)XRSPND(LDl)»KR2PND <RZPN3=XRZPND*1933 L 1 *L1♦1L = L1-'IJMJHFIF(MANAGE.Ea.l)33 T3 62 00 931 LM=1,NSPS 931 0CCNJM(LM,L1)*3.DO 932 LM = 1,NUCLON L MI = XU<(LMI(F(LM.Gr.NurRON)GO TO 935 3CCNJKILM1.L1)=3CCNUM(LM1,L1)♦!.935 IF(l1.E3.1.JR.LM.LE.NUTR3N)30 TO 902 904 DCCNJM(lM1,L1)*0CCNUM(LHI,L1)»1.902 CONTINUE

C WRITE I 6, 1002)LI,IXUX(LM), LM*1,NUCLON)1002 FORMAT!HO,13,5X,1213)!F(J3J.N5.1)WRITEI6,1003)PLJS,PLUS,<XUXILM) , LM*KKX,NUCLON), (XJ<(LM),LM*l,NUrRON)1003 F3RMAT(A1,50X,A1,12I3)GO TO 93CC CALCJLATE THE NEJTR3N-PR3T3N INTERACTIONS62 REWIND 1 REWIND 3WRITE(9,33S3)LINE,LI,RIGHT 3353 FORMAT!IX,2HH , Al, 12 , IX,A1)DO 55 ISJB*1,JJMAX iI*.{ ISJ3»2)/2 . 'IF(MOO(ISJB,2).E0.1.AND.ISJB.NE.1)GO TO 912 NCHM= NCMAXI 1,1)00 913 L M2 * 1» MAX IN

913 REA0I8)((P0INT(LMl,LM2,LM3),LMl*l,NCMM),LH3-t,2) 912 LIMIT*MAXO(XOUNTRI1,113,1),XOUNTRII,JJ3,KK)1 DO 906 MN=1,LIMIT DO 906 MP=1,LIMIT 906 COUPLE(MN,MP)=O.DO DO 39 KI*l,NUTRON <<1*<JXI<1)M1=MC00E1XK1)DO 33 KX1=1,NSPSM3 = MC0DEI XX 3 IXJ<( <D=<<3MDIFDM3-M1M*IIABS(MDIFII1/2*1IFIM0IF1.GE.0IG0 TO 65IF( ISJB.NE.-M0IF1IGD TO 3800 153 NN*I« NUT RON NE MP *XUXINNJ163 MU<(NN)=MODULO(NEMP)■ CALL LOCATE!SIGN1,XUX,MM,NUTR0N,0)IFISIGNl.EQ.O.130 TO 38CALL LOCATE!DUMMY,MUX, MN,NUTRON,1)1 T RY = 2 GO TO 6765 IF! ISUB.NE.MOIFDDGO TO 3BCALL L0CATE(SIGN1,KUX,MN,NUTRON,1) IFISIGN1.E0.0IG0 TO 38 IT RY * 1C 67 MN*MN-NJ(1,1)MMN = POINT IMN,I 13,ITRY)03 60 X2=XXX,NUCLON XX2*<UX(<2)M2 = MC ODE IXX2)MPRIME=M1*M2 MSTAR=MPRIME/2*1 DO 51 XX4=1,NSPS MA = MC ODE IXX4)IFIM3+M4.NE.MPRIME)SO TO 61 XJXlX2)*XX4IFIMDIF1.GT.0IG0 TO 182CALL LOCATE ISIGN2.KUX(XXX),MP,PROTON,XXI IFISIGN2.E0.0.IG0 TO 61 ITRY*X GO TO 191182 00 133 NN=XXX,NUCLON NEMP=XU<( NN)183 MUXINN)=M3DUL0(NEMP)CALL LOCATE!SIGN2.XUX(XXX), MP,PROTON,0)IFISIGN2.EQ.0.130 TO 61CALL LOCATEI DUMMY,MUXIXXX),MP,PROTON,XX)ITRY*XXXXc 181 CALL HF2B0YIMRETRN.SIGN2)GO TO ( A1,A2,43,44,45,46,47,48),MRETRN41 TEM?=B0Y21(LLLI GO TO 4042 TEMP»BOY22(ILL)GO TO 4043 TEMP=B0Y23(LLL)GO TO 4044 TEMP=B0Y24(LLL)GO TO 43

191

Page 265: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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Page 266: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

IF(MMPl.LE.O)GO TO 22X=C0UPLEIMMNl, MMP1)Z3C30U,MN,.Xl)*CDFU,HP,,JK21 Z 13ZIF CI3UBLL.E3.OI30 T3 208TEM9 = C3f t 1,MN, J.<1)*C30(1,MP, JK2)z=z+tempZ1=Z1-TEMP238 cj?l=cj?l+x*z: JPL1=cJPL1+X*ZI22 C3NMNJE23 CONTIN JEC 87 00 34 MJ=1,JMAX 31 AN T = 3.GIANT 1 = 3.LM33A13MAX0(3,MU-JK2)«-1 LM33»2=MIN0(JK1.MU)IF(LMB341.GT.LM3DA2)G0 73 34C <AP?A3MJ-LMBDA1+1 *00 23 IAMBOA=LM30A1,LMB3A2 bIN0=B!N3M<MJ,LAMBDA)S I CM A =0.SICMAIO.COE3S«C3E0I LAHBDA, J<11*C3ED(KAPPA,JX21*8INO IF(MANA3E.E3.O.3R.H.EQ.l.0R.MU.EQ.l)SO TO 21 I3TA1=LAMB3A+M-1 )OTA2=LAMB3A“M+lIFIMIN3IJ<1,J<2,MAX3ILAM334,KAPPA>).LT.M>30 TO 20 RAT !3 0S3RT(C3E3(M, JXD/COEOIM, JK2II 9I-N31 = 3In3M(MU,I3TA1)+RATIO IFILAM33A.3E.M)3IN02-BIN3MIMU,I3TA2I/RATI0

C NNN=NCM4X(M,1 I 03 52 MN=1,NNN1 031 ? 3 3 I 031 M = 3MMNl = P3INT(MN, 113,1)I F tMMN1.3T.3I 1031P3l MMN3-P3[NT(MN,113,21 1FIMMN3.3T.31 I 031M= 1 IFd30VPd031K.E3.0IG0 TO 52C NNP=NCM4X(M,XX1 DO 51 HP=I, NNP ID33P=3 ID33M=3 • MMP1=P3INT(MP,JJ3,K)IF(MMP1.3T.0)I033P=l MMP3=P0INT(MP,JJ3,K<XK)IFIMMP3.3T.31I033M°1 IFd333Pd033M.E3.0>50 TO 51 I035P=I031P+ID33M I005M=I331M*ID03P IFII305PUD35M.EQ.OIGO TO 51C Xa3.X 1 =3.

1 = 3.11-3.X X13 3 •

IF( ID05P.EQ.01G3 TO 732 XX13CQ'J?EL(MMN1» MHP3) *B IND1 X=COOI1,MN,JX11*COF(2,MP,JX2I XI = XIF(IOUBLL.EQ.OIGO T3 732 TEM?=COF(1,MN,JU 1 *C3D( 2,MP, JK21 X=X+TEMP XUX1-TEMP 732 IFII005M.E0.01G3 TO 849XX23C0J?LElMMN3.MMP1I*BIN02 Z=C33I2,MN,JXI)+C0F(I,MP,JX2)Z1 = ZIFd3UBLL.E0.01G3 T3 849 TEM?=C3F(2,MN,JUUCODII,MP,JK2)Z3ZdEMP ZUZl-TEMP 849 IFILAMB3A.lt.H1G3 TO 8492 SI3mA=SI3MA+Z*xX2 SIGMA1=SIGMA1+Z1*XX2 8492 IF1MJ.LT.I0TA1130 T3 51 SIGma=sigma+x*xxi sigmai=sigmai+xi*xxi51 CONTINUE52 CONTINUEc 21 XO.XlO.IFIM.NE.DG0 TO 215 X=YPRtMl+yPRIM2 X13Y?RIM1-YPRIM2 IFIMANA3E.E3.0I30 TO 215 X-X+YYI+YY2 X1=X1+YY1-YY2215 3I4Nr=GIANT + C0E3S*(3IN0*IX«-CUPL»+SI3MA)3IANri=3IANTl+C3EDS*IBIN0*(Xl+CJPLlI+SI3MA1) 20 <APPA=X4PPA-1COTT ( MUUCOTT (MJI+GIANTl 34 COTIMJ)=C0T(MU)+GIANT 86 CONTINUE 84- CONd NUE334 CONTINUECALL SOLVE I COT I CALL SOLVEICOTT)335 00 2535 J31,JMAX IFILI.NE.1IG3 TO 2534 C3T(JI=C3T(JI*.500 C3TTI JIOOTTI Jl*.5002534 Y( I, J, L1=COT(JI Yt2, J.LUCOTTI J)2535 IF(13JBLL.NE.1)Y(2,J,L)B0.802 IF! JJI.E3.MAXIP1G0 TO 2525 CONTINUE26 1F(JJ3.EQ.MAXIPIG0 TO 2727 IF(II3.E3.MAXINI50 TO 2400C 2403 WRIT E(3 I VIFIMANAGE.EQ.DRETURNMANAGE3!GO 13 910 2010 RETURN ENO

XX2»3.

Page 267: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SJBROJTINE COJPLEIIISPIN.Y.OOUBLE.KRSPNO.STATE.INDEX.NJ.ADJUST, PROBLM.OCCNUH)DIMENSION Y(2,15,55),YY(15,55).INDEXI10,10).OCCNUM(12,10) ,ASTI 133),I NO( ID>,NUMBR(3,41,OCCUPY I12,10,3)DIMENSION <RSPN3< I) , STATEI I1,NJ11) ,PR03LMI20),PLOT 12253), NM3RS(2250),TITLEStS,41 C OMMON/1 NTEGR/NJTRON, PROTON, N'JCLON, MOOUL , JMAXN, JMAXP, JMAX, NSPS, JTO.LENTHN.LENTHP,LENGTH,NUMJN.NUMJP.NUMJ,MAXIN,2 MAXIP,NUMJHF,<0NTRL(5),M4TR0N,NSPSPI»10FINDINTEGER DOUBLEINT£GER*2 KRSPNO,STATE,NJ,INDEX,INODATA TIT LES/4HALL , 4HC3NF, 4H13UR, 4HATI 0 ,4HNS , 4HHART, 4HREE • 4HF3C<,4H STA.4HTE ,4HH = A, 4HN3 2,4HP-2H,4rt STA,2 4HTES , 4 HHF A, 4HNJ 1,4HP-1H,4H STA,4HTES /CALL LOAD SCHMIT I FLAG-3 XOJNTR-OMAXIN0=INUMJHF*(NUMJHF*in/2 REWIND 300 SOD MANAGE-!,?REWIND 8 I3FIN0-1 RE AO(3)Y REWIND 1DO SOO ISPIN-l.IISPIN DO I L-l.MAXIND DO 1 JJ-l.JMAX1 YY(JJ.Ll-O.IF(MANAGE.E0.2IGO TO 3 DO 2 JJ-l.NSPS 00 2 L-l.NJMJHF2 OCCJPYIJJ,L,ISPINJ-D.

3 L - 1DO 450 11-1,4 00 400 J 1 - I 1,4GO TO (1000,2000,3000),ISPIN-: T = 0 STATES1000 GO TO ( HOD, 1203, 1330,450), II 1100 GO TO (1110,1120,1130,450),J11110 DO 1111 JJ-l.JMAX1111 YYIJJ , 1) «YI l ,JJ, l ) IFIMANAGE.E3.21G0 TO 400 DO 1112 JJ-l.NSPS1112 OGGJPYIJJ,1,1)-OGCNJMIJJ,I)GO TO 4031120 DO 1122 <1=2,NUMJHFIF(STATEK1).NE.2)G0 TO 1122 L-LH00 1121 JJ-l.JMAX YY<JJ,L)»Y(1,JJ,K1) 1FIMANAGE.E3.21G0 TO 1122 00 1123 JJ-l, NSPS OCCJPYI JJ,L, ll-OCCN'JMI JJ,<1)*.5 CONTINUE 30 TO 403

1121

11231122

1133 DO 1132 <1-2,NUMJHF IF(STATE(<1).NE.3)G0 TO 1132

K2-XRSPN0IK1)L»L*1DO 1131 JJ-l.JMAX1131 VY(JJ,L)«Y(l,JJ,<n-r(l,JJ,K2>1FIMANA3E.E0.2130 TO 113200 1133 JJ-1,NSPS1133 OCCJPYIJJ,L,1)-(0CCNUM(JJ,<1)*0:CNUM(JJ,K2))*.251132 CONTINUE GO TO 450C1200 GO TO (400,1230,1230,450),J1 C ALSO USEO FOR T » 1 STATES1230 Ml=1 1F(I1.GE.3)HI«M1»D0UBLE1 F( I 1 ,E3.4)M1 = M1*00U3LE LOW-200 1233 <1-2,NUMJHF IF(STATE(<1).NE.I1)G0 TO 1233' MI-MI♦ 1IFIIl.NE.JDGO TO 1234M2-W1-1LOW-<150 TO 12351234 M2 -1IF!Jl.GE.3IM2-M2*DOJBLE1 FIJ1 .E3.4)M2-M2*D0UBLE1235 00 1232 <2-L0W,NUMJHF IF(STATE(<2).NE.J1)G0 TO 1232 M2-M2 *1X4=INUEX(<1,<2)K3-<RSPND(<21 X5=IN0EK(R1,X3I L- INOEX(Ml,M2)00 1231 JJ-1,JMAX YY(JJ,L)-Y( ISPIN,JJ,X4)1231 IFIISPIN.E9.1.AN0.J1.E9.3)YYCJJ, L)■YYIJJ, L) - Y(I , JJ, X5)1232 CONTINUEIF! ISPIN.NE.2.OR.MANAGE.EQ.21G0 TO 1233 00 1236 JJ-l,NS?S1236 0CCJPY(JJ,M1,2)-OCCNUM(JJ,X1)*.S1233 CONTINUE GO TO 400CC ALSO USEO FOR T - 21330 Ml =DOURL E*1 SIGN-l-l.)**(ISPIN/2)00 1333 <1-2,NUMJHF IFISTATEKII.NE.11130 TO 1333 Ml-Ml*1K3=<RSPND(<1)M2-M1-100 1332 <2-Kl,NUMJHF IF(ST4TE<K21.NE.J1>50 TO 1332 M2-M2 * IX5-INDEXI <1*, <21 X8=IN0EX(<3.<2)K4*<RSPND(K2)K7-INDEX(<3,<4)K6=INDEX(<1,<4)L-IN0EX1M1.M2)DO 1331 JJ-l.JMAX1331 YYIJJ.LI-YI 1,JJ,<5)*YIl,JJ,K7)*SISN*CV(l,JJ,X3)fYIl,JJ,Xi))

Page 268: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1332 CONTINUE IF(ISPIN.NE.3.3R.MANAGE.EQ.2)GO TO 1333 DO 1334 J J• I, NSPS1334 OCCUPY!JJ,Ml,3)=(0CCNUM(J J , < 1 > OCCNUMIJJ,K3))*.251333 CONTINUE GO TO 4-50s~200D IFtll.ED.llGO TO 450 GO TO 1230 3003 I F(I 1.E3.3.4ND.J1.69.3)30 TO 1330 400 CONTINUE 450 CONTINUE503 WRITE 2 I OF I NO.4444 YY J,< ,J l.JHAX ,K l.MAXINO 4444 FORM A T(90A4)C XOJNT = 1DO 545 < ASE* I« 3GO TO (526,527,528),<ASE526 L0* = lLlMIT =NJMJHF GO TO 529527 L0W=DDJ3LE+2 LI MlT =NJMJHF GO TO 529528 L3w=1L1 MlT =D0U8LE + lC 529 I OF IN0=100 544 ISPIN*1,11 SPIN IF(<ASE*ISPIN.E3.6130 TO 544READ 2 I OF I NO,44441 Y 1,J,K ,J 1,JMAX ,K l.MAXINOL * 000 530 1=1,NUMJHF DO 530 J = I.NUMJHF L = l + 1IF!I I.NE.l.ANO.II.IT.LOW.OR.I.GT.LIMIT)).OR.(J.NE.l.AN0.1J.LT.LOW.OR.3*GT.LIMIT))IGO TO 534 00 532 JJ=1,JMAX 532 YY(JJ,L)=Y(l,JJ,L)IFIMANAGE.EO.l.OR.J.NE.IIGO TO 530 DO 536 JJ=1,NSPS 536 OCCNJM!JJ,I)=OC:uPY(JJ,ItISPIN)GO TO 530534 00 535 JJ=1,JMAX535 YY1JJ,LI=0.IFIMANAGE.EO.l.OR.J.NE.IIGO TO 530 DO 5 3 T J J = 1,NSPSP■ 637 OCCNJM!JJ,I)=0.530 CONTINJEC GO TO 154D,541),MANAGE540 DO 542 JJ*1,JMAX 542 NJ(JJ)=NJMJHFCALL SCHMU ( YY, AST , N J , NUM JHF .NUM3ER, I NOEX, ISPI N-I , XASE ) NJM3R!I SPIN,RASE)“NUMBER IF(<ASE.EO.l)KOJNTR = OUNTR*NUMBERIF!RASE.EO.l.ANO.NJ!JMAXI.E3.0)IFLAG=1 ,GO TO 544541 CALL ORMDN! YY, AST, NUMJHF. I SPIN-1,PLOT! AOUNTI.NMBRSKOim),< AS E.OJNTR, I NOEX, AD JUST, OCCNUM) <DJNI=<DJNT+NUMSR<ISPIN,<ASE)544 CONTINUE

IFIMANA3E.E0.UG3 TO 545NUMBER*MODIXOUNT.KOUNTR 1-1IF((ASE.E0.1)NUMBER“JMAX/2UIFKASE.EO.l.ANO. I FLAG.E3.1)NUM3ER-NUMBER-lIF!XASE.EO.l )<DUNT = <DUNT + NUMBER<=<0UNTR-NUM3£RIFK.EO.OIGO TO 544DO 546 L* I , <PLOT!OJNT)*PLOTUOJNT-1)NMbRS ! RJ'JNT ) = 7777 546 XDUNT=<3UNT*1 545 CONTINUE 603 CONTINUECALL LOAD PLOT REA0!5,1032)NUMPAG 1332 FORMAT!13)CALL 01 AGRMlPRD3LM,NUMPAG,TITLES,2,KOUNTR,PLOT,NMBRS,O,5,l,60.)X3UnT = <0UNTRUCALL DIAGRMIPROBLM.NUMPAG,TITLES!1,2) ,3 ,K3UNTR,PLOT(KOJNT), NMBRSIXOUNTI,0,5,1,60.)RETURNEND

195

Page 269: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

no

n

S JBRO'JTINE SCHMIT(Y,AST,NJ« NUMBER, NUMB, INDEX,ISO*KASE)DIMENSION ASTINJMBERtDtNJIDDIMENSION Y( 15,55),BST(10,10),I4RAN3U0),JARANGU0),!NE<10),1N0(10) ,INDEX!10,10)COMMON/INTEGR/NJTRON.PRDTON,NUCLON,MODUL, JM4XN,JMAXP,JMAX,NSPS,1 ‘ jrO,LENTHN.LENTHP,LENGTH,NUMJN,NUMJP,NUMJ,MAXIN,2 MAX1P,NUMJHF,<0NTRL 5 , MAT RON,NSPSP1, I OF I NO INTEGER PROTONI NTE 3ER*2 NJ, INDEX, I NO.IAR4NG.JARANG,INEA SCHMIDT 0RTM0N3RM4LIZAT10N IS OONE ON THE SCALAR PRODUCTS OF STATES.MAXI ND=(NUMJHF*(NUMJHF*1))/2 NJMB = 3 244 00 251 M=1» J MAX MM = M- 1 N X =N JIM)WRITE(B)(Y(M,X),<«1,MAXIN0)IFINX.EO.OIGO TO 251 BOUND*.01 < OunT 5 O 355 00 5 IT 1*1,NUMBER INDI IT1) = 100 5 IT2=1.NUMBER 5 ASTI IT1, 1T2)=0.

C 1 = 1II = 04 <=NJMdER*<1-1)-(I * CI-3 ) )/2 IF1Y(M,O.GT.I.E-3)GO TO b 1*1*11FIf. GT.NUMBER I 30 TO 3 GO TO 4C 5 ASTI I,I I«l./SORT(VCM,X))IFIOJNIS.EO.l) 1FIN0*IARANGC I)101*1*1I NO I I ) = 0IFIOJNTS.EO.D33 TO 30 IAR4N3I1)*I JARANGII)=1 30 IFINX.EO.DGO TO 78II = 1IF!I?1.3T.NUMBER)G0 TO 300 11 I * IP1,NUMBER1 Ml = I-1I1PL*I1*1CC CALCJLATE NUMERATORASTI I ,11 = 1.DO 7 J*l,IM1IF!INDIJ).£0.1)30 TO 7T E M° = 0.N X 1 = 000 30 <2=1,II81 <4*NX1*<2IF(IND(<4).EO.O)30'TO B2 , jNX1*NX1*1GO TO 3182 < = I 'O E X II,X4)S 1 = Y 1 M , < )L = MA X 0 I<4,11

o o

00 80 Xl*l ,l l83 X3»NX2*<1 IFIINDI<3).EO.OIGO TO 84 NX2=NX2*1 GO TO 8384 !F(<3.ir.L)G3 TO 80 TEM, =TEMP*ASTIK3,X4)*ASTIX3,J)*S180 CONTINUEASTI I, J)=-TEMP 7 CONTINUEFIND NORMALIZATION TEMP=0.00 92 JI*1,IIFIASTI J 1, JD.EO.O.IGO TO 92DO 91 J 2 = 1,JIIF(ASf(J2,J2).EO.O.)GO TO 91 J=INDEX(J1,J2)S1 = AST< I.J1KASTI !,J2)*YCM,J)TEMP*TEMP+S1IF(J1.NE.J2ITEMP*TEMP*S191 CONTINUE92 CONTINUE IFITEMP.GT.BOUNOIGO TO 10093 DO 12 J*l,I 12 ASTI I , J) = 0.GO 10 11

100 Sl=l./S3RT(TEMPI INDII 1 = 0IF(<0UNrS.EO.l)IFINO*IARANS(I)11 = 11 PIIFKOUNTS.EO.DGO TO 31 IARANGI11)°I JARANGII)* 11 31 DO 10 J=1,I10 ASTI I , J)°AST(I,J)*S1101 IFIIl.EO.NXIGO TO 7711 CONTINUE

C REARRANGE SO THAT STATES ALREADY FOUND ARE PROCESSED FIRST 77 IFK3JNTS.E0.DG0 TO 62 XOUNTS=<OUNTS*1 x=o L = U03 63 1 = 1,NUMBERIFC INOII).EO.OIGO TO 59L = LHIARANGIL)=I JARANGI D»L59 00 60 J*I,NUMBER X = <*1ASTI I , JI*Y(M,K)60 ASTIJ, I)=AST I I , J)DO 51 1=1,NUMBER1 11 = IARANGII)DO 51 J=l,NUMBER J1=IARANGIJ)61 BSTI I , JXASrt I II, Jl) x=o

Page 270: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

n n

DO 66 1=1,NUMBER 03 66 J»I,NUMBER < = <♦1 66 Y(M,<)=3ST(t,JI B3JN3=« 3338 G3 T} 366RETJRN 13 ORIGINAL 3RDERIN3 6? 33 63 1 = 1,.NUMBER INE CI I * IND(1 I DO 63 J=l,NUMBER63 BSE!I,J)=AST<I, J)DO 64 I-l.NJMBERI I 1 = JARANGII I INDI IU1NEIIII I 03 64 J=l,NUMBER Jl=JARAN3(J)64 AST ( I , J UBSTI 11 1, J 1»3 NJIMUI178 NJMR N'JM3 IIWR I Is I 11 11. < INQI J> ,J»1, NUMBER). MAST ( I . J ) .J*1 . NUMBER) , 1 * 1 , NUMBER! 251 CONTINJERETURNENO

197

Page 271: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

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(SI •A tt 3IN m* 0* 444BnG *G A b4 4Vw bA rg40o o 44GO 3 04 g* w X0- 04UiG Oec O tt 04GG f t a a Ui tt Ui tt gUJUJ UJ tt o (O A a — « *• 4“3 m 3 44 B y 44y A-4»4rg rgX £ y <b4 b43 «3 •rg4444 443 3 3 • b4 • Z Or O tt tt 4 rz Z Zo 44ft 4UJ 4UJ44•—A AAA 4Ui AUJA • A • 4 444 4“*AA •4 • a4 « IIA UB4b4A«4» 44II II 3 II A II AAArgrgXI44X XA rg. nA ArgrgXIXItt tt 4444 II ItM AB04 44 »B44B. UJUJ4ftrg 4BXtt rg3 3 Aft ft rgo 4* Qrg3 AO LLi 44Z ZA«nXI AXIz g z 04Z04z 3 u 4ft- 44 A. A4AAAAA4A44A 44z CLA0— rgA4 AB BB w 4B44y 44Z z 443 3 AB3 U. 3 u. 3 U. n u. NUI 443 3 4*3 O XOr- O44Own —•bJi—TCl Ci Tin ri ^ o rg n crv ft*x> xi

Page 272: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

S35953541311

1336C 20319

251C

G3NT1NUECONTINUE3CCJPY(NJM3C)"SJN WRITEI6,1011)1,OCCUPY F 3RH A T( IX,12,IX,12F9.4)WR ITEI 6, 1305)F3RM4T(M3,12311H.))03 19 1131,NX PLOT! IC3JNT)= A<II)NNBRSI IC3JNT)»IS3SPN icojnwcdunt + iIF(<&SE.NE.1.0R.IS0.NE.0)53 TO 251 IFM33I J,2).E0.3)G0 TO 251 PLDT( K3JNT)=H(1,1)NN3RS(<3JNT)=J-1 OJNT = < 3JNT♦ I 3 3N rINUERETURNEN3

Page 273: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

200

APPENDIX B-III

GENERAL PURPOSE COMPUTER CODES

The following general purpose subroutines are included

in this section:

(1) Double Precision Function COFCG - generates Clebsch-

Gordan coefficients in double precision.

(2) Double Precision Function BICO - generates binomial

coefficients in double precision - needed for COFCG.

(3) INVERT - Inverts a matrix.

(4) HDIAG - Diagonalizes a real symmetric matrix by the

Jacobi Method.

(5) Function RACAH - calculates Racah coefficients.

(6) SYMEIG - Calculates the eigenvalues and eigenvectors

of a real symmetric matrix.

(7) READER - skips input data cases on input tape.

(8) DIAGRM - plots energy level diagrams with variable

scales.

Page 274: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

OOUBLE PRECISION FUNCTION COFCGIA.B.C.X,Y.ZIOOUBLE PRECISION A,B,C,X, Y.Z,X1, VI,Z1,X2,Y2.Z2,Z3.R,S,T.U.GOOUBLE PRECISION BICO OOUBLE PRECISION SUM,TEMP IF(C-A-B-0.1)301,301,302302 COFCG“0.00GO TO 300 0030301 IFIA-B-C-0. 1)303,303,302303 IFtB-A-C-O.1)304,304,302304 IF IABS(Z-X-Y)-0.1)305,302,302305 NMAx»NINHC-A*B*.l,C*Z*.l)IF((ABS(Z)-C).GT.0.1)GO TO 302 NM[N=MAX1( .1 ,B-A*Z*.1)SUM*0.00CCFCG*1. DOX13 A* X 0110Y1 =H ♦ Y 0120Z1=C*Z 0130X2 = A-X 0140Y2 = B-Y 0150Z2=C-Z 0160Z3=2.00*C+1.00 R*A* 8 *C*1,000S=C*B*X 0190T = B*C -A 0200J * Y 1 * • 100 306 l=NMIN,NMAX 0220U» I306 SUM=SUM»(-1.D0>*MI+2>*BIC0IZ1,U>*8IC0IS-U,X1)*81C01X2*U,YIJ SUM*(-1.0001**IJ*2)*SUMIF|ABSIX>-0.1)12.12.112 112 IF(X)11,12,1311 TEMP=BIC0(X2,X1)IFIIEMP.GT.0.5)G0 TO 401G=0.00GU TO 201401 G*I.00/TEMP201 L=-lGO TO 14 029012 G=1.D0L*I 0310GO TO 14 032013 G=BIC0(Xl,X2l 0330L*1 034014 IF(ABSIY)-0.1)16,16,114 114 IFIY) 15,16,1715 TEHP*BIC0(Y2,Y1IIF(TEMP.GT.0.5IG0 TO 402 G*0.00 1GO TO 202402 G*G/TEMP202 l=L-2GO TO 18 041016 L = L»2GO TO 18 038017 G=G*8IC0(Y1,Y2) . ' 0420L=L*2 043018 IFIABS(Z)-0.1)20,20,118 118 IF(Z>19,20,2119 G = G»8IC0U2,Z1) 0450L=L-3 0460GO TO 22 0470

20 L»L*1GO TO 22 osoc21 TEMP*B1COIZl,Z2)IF(TEMP.GT.0.5)C0 TO 425 G*0.00GO TO 225 425 G*G/TEMP 225 L=L*122 L=(8»L)/2 05J0GO T0(23,24,25,26,27,28),L 054023 G=G*BICO(-2.D0*Z,-2.00*X)GO TO 307 056„24 TEMP=8IC0(-2.D0*Y,-2.D0*Z)•IF(TEMP.GT.0.5)C0 TO 403 G*0.00GO TO 203 403 G=G/TEMP 203 GO TO 30725 rEMP=BlCO(-2.00*X,-2.00*Z)IF(TEMP.GT.0.5)G0 TO 407 G*0.00GO TO 307 407. G*G/ TEMPGU TO 307 060026 G=G*81C0I2.D0*X,2.00*Z)GO ro 307 062027 G=G«BICO(2.D0*Y,2.00*Z)GO 10 307 064028 TEMP=8ICO(2.00*Z,2.00*XJ IFITEMP.GT.O.SIGO TO 40B' G°0.00 GO TO 307408 G*G/TEMP •;307 TEMP*BIC0(R-l.00,2.00*O*BIC0«2.00*C,T)*R IF( rEMP.GT.0.5)G0 TO 499 C0FCG=0.DO GO TO 399499 COFCG=CUFCG*SUM*OSQRT(G*Z3/TEMP)399 RETURN 067„ENO 068()

Page 275: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

1201202203 1203204

20820520/

DOUBLE PRECISION FUNCTION BIC0(A,8)DOUBLE PRECISION A,8,X,Y,UX-A-B 0010IF(ABS(Xl-0.1)202,202,1 IFIXI201,202,203 BIC0-0.00CO TO 207 0040BICO-l.OOCO TO 207 0060IF(ABSIB)-0.1)202,202,1203 IF(6)201,202,204 Y = DMINMD,X>BICO-A/YJ-Y-.91FIJI207,207,208 CONTINUE 00 205 I>1,J U-IBlCO = BICO*t A-UI/ ( Y-UI 0130RETURN 0140ENO ' 0150

SUBROUTINE INVERT!A,N,KKK,0ETERM)C DOUBLE PRECISION MATRIX INVERSIONDOUBLE PRECISION A,B,WORK,AMAX.T,PIVOTDIMENSION A(KKK,KKK),IPIV0T(50),INDEX!50,2) 0ETERH-1.0 00 1 I"I, Nl iPivorm=o00 108 1=1,NC SEARCH FOR PIVOT ELEMENTAMAX-0.00000 103 J = 1,NIFMPIVUTt JI.EQ.l) GO TO 103 DO 3 K=1,NIFUPIVUT(K).EQ.l) GO TO 3 IF(OABS(AMAX).GE.OABS(AIJ,KI II GO TO 3 IROW = J ICOLUM=K AMAX = A IJ, KI3 CONTINUE 103 CONTINUE1 PIVOT! ICOLUM)*I PIVOT1ICOLUM)*!IFIIPIVUTI ICOLUM).GT.l) GO TO 13C INTERCHANGE ROWS TO PUT PIVOT ON 01AGONALIF IIROW.EQ.ICOLUM) GO TO 5 00 4 J = 1,N T=A(IROW.J)A< !ROW,J)=A(ICOLUM,J!

4 A(ICOLUM,J)=T5 INDEX 11, 1) = IRCW INOEXII,2)=ICOLUM PIVOT-AIICOLUM,ICOLUM)C DIVIDE PIVOT ROW BY PIVOT ELEMENTAlICOLUM,ICOLUM)>1.000 00 6 J=1,N6 A(ICOLUM,J)=A(ICOLUM,JI/PIVOT C REDUCE NON-PIVOT ROWSDO 8 J=l,NIF I J.EQ.ICCLUMI GO TO 8 T-AIJ,ICOLUM)Al J,ICOLUM)=O.ODO 00 7 K=1, N7 A(J,K)=A(J,K)-A(ICOLUM,K) *T8 CONTINUE108 CONTINUEC INVERSION COMPLETE, PUT COLUMNS IN CORRECT ORDER00 109 1*1,N J=N*1-IIF(INOEX(J,11.EQ.INOEXIJ,2)) GO TO 109 IROW=INOEXIJ.l)ICOLUM-INOEX(J,2)DO 9 J=1.N T=A(J.IROW)A(J,IKOW)=A(J,ICOLUM)Al J,ICOLUM)-!9 CONTINUE109 CONTINUE RETURNC SINGULAR MATRIX INDICATION13 DETERM=0.0 RETURN ENO

202

Page 276: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

no

n

10

11121415

17

2030

SUBROUTINE HOIAGIH.N,IEGEN,U*NR,X,IQ,NDIM) 'HD1AG - DIAGONALIZATION OF A REAL SYMMETRIC MATRIX.USES THE JACOB I METHOD CALLING SEQUENCE FOR 01 AGONAL IZAT ION‘CALL HOIAG(H,NtIEGEN,U,NR,XtIQ,NDIM)WHERE H IS THE ARRAY TO BE DIAGONALIZED.N IS THE ORDER OF THE MATRIX, H.IEGEN MUST BE SET UNEQUAL TO ZERO IF ONLY EIGENVALUES ARE TO BE COMPUTED.IEGEN MUST BE SET EQUAL TO ZERO IF EIGENVALUES AND EIGENVECTORS ARE TO BE COMPUTEO.U IS THE UNITARY MATRIX USEO FOR FORMATION OF THE EIGENVECTORS.NR IS THE NUMBER OF ROTATIONS.X » WORKING STORAGE IQ = WORKING STORAGENDIM » SIZE OF ARRAYS IN MAIN PROGRAM DIMENSION STATEMENTTHE SUBROUTINE OPERATES ONLY ON THE ELEMENTS OF H THAT ARE TO THERIGHT OF THE MAIN 01 AGONAL. THUS, ONLY A TRIANGULAR SECTION NEED BE STORED IN THE ARRAY H.NOTE THAT THIS PROGRAM PRODUCES ORTHONORMAL EIGENVECTORS FOR DEGENERATE EIGENVALUESDIMENSION HINOIH.NOIMI, UI NO IM,NOIM1,XINDIM), IQ INDIM)SET I NO ICATOR FOR SHUT-OFF.HDTEST=l.0E300RAP=2.0**t-48)IF IIEGEN .NE. 01 G0T015DO 14 1 = 1,N00 14 J=1,NIF( I .EQ. J i l l , 12U(I.J)=1.0GO TO 14U(I,J1=0.CONTINUENR = 0IFIN .LE.•11GOTOIOOOSCAN FOR LARGEST OFF DIAGONAL ELEMENT IN EACH ROMXII) CONTAINS LARGEST ELEMENT IN ITH ROM10(1) HOLOS SECOND SUBSCRIPT OEFINING POSITION OF ELEMENTNMIl=N—I DO 30 1 = 1,NM11 XII) ° 0.IPH=I*1 00 30 J=IPL1,NIF ( X(l) - ABSFI HI I , J11) 20,20,30 'XI I) = ABSFIH tI,J)I IQ(I )=JCONTINUE ^FIND MAXIMUM OF XII) S FOR PIVOT ELEMENT ANO TEST FOR END OF PROBLEM

6HDAG000 6H0AG001 6HOAG002 6HOAG003 6H0AG004 6HDAG00S 6HDAG006 6HDAG007 6HDAG008 6H0AG009 6HUAG010 6UOAGOU 6HCAC012 6HCAG013 6H0AG014 6H0AG015 6HDAG016 6HOAGO17 6H0AG018 6H0AG019 6H0AG020 6H0AG021 6HUAG022 6HDAG02 3 6H0AG0246MDAG025 6HDAG026 6HDAG027 6HUAG028 6H0AC029 6HDAG030 6H0AG031 6H0AG032 6H0AG033 6H0AG034 6HDAG035 6H0AG036 6H0AG037 6HDAG038 6H0AG039 6HDAG040 '6H0AG041 6H0AG042 6H0AG043 6H0AG044 6HUAG045 6H0AG046 6H0AG047 6HDAG048 6HDAG049 6HDAG050 6HDAG051 6H0AC052 6HUAG053 6HDAG-054 6H0AG055 6MDAG056 6H0AG057 6MDAGU58 6HQAG059 6HOAG060

u o

404560

70

BO8590

150

DO 70 I-L.NMllIF( I .LE. 11G0T060IFIXMAX . G E . X(I) 1 G 0 T 0 7 0XMAX-XlllIPIV=IJPI V=I0(11CONTINUEISIFIFIF

100110

MAX. XII) EQUAL TO ZERO*I XMAX) 1000,1000,60 IHDTEST) 90,90,85 IXMAX - HOTEST) 90,90,148 HOIMIN = ABSFI HI 1,1) )00 110 1= 2,NIF (HOIMIN- ABSFI HU,DM 110,110,100 HOIMlN=ABSFIH(1,1 I )CONTINUE

IF LESS THAN HOTEST* REVISE HDTECT

HDTEST=HDIMIN*RAP

148RETURN IF MAX.HI I *JILESS THAN!2**-481ABSF(H(K,K1-MIN) IF (HOTEST- XMAX) 148*1000,1000 NR « NR*1

6HDAG06I6H0AG062 6HDAG062 6H0AG064 6H0AG065 6HCAG066 6H0AG061 6HDAG068 6HOAG069 6HCAG0 70 6HCAG0 7 I 6HDAG0 72 6H0AG0 7 3 6H0AG0 74 6H0AG075 6HDAG076 6HUAG077 6HCAG078 6HDAG079 6HDAG0d0 6HGAG0BI 6H0AG0B2 6HDAG033 6H0AG0B4 6H0AG085 6HCAG0B6COMPUTE TANGENT* SINE ANO COSINEtHII,I) ,H(J*J)TANG=SIGNF(2.0,(H(IPIV,IPIV)-H(JPtV.JPIV)))*H(IPIV,JPIV)/(ABSFIHII6HDAG0B7 IP I V.IPI VI-HI JPIV«JP1VM+SQRTFI IHI IP IV , IP IV >-HI JP1V, JP IV ) )**2*4.0*H6HDAG0BB 2(IPIV,JPIVI**2I) 6HCAG069COSINE=1.0/SQRTF(l.0+TANG**2) 6HDAG090SINE=IANG*COSINE 6HDAG091HII=H(IPIV,IPIV) 6H0AG092HIIPIV,IPIV)=C0SINE**2*(HII*TANG*(2.*H(IPIV,JPIV)*TANG*HIJPIV,JPIV6HUAG0931)1)HIJP1V,JPIV)=C0SINE**2*(HIJPIV.JPIV)- iim HI IPIV,JP)V)=0.

TANG*(2.*H(IPIV,JPIV)-TANG*H

152

153

PSEUDO RANK THE EIGENVALUESAOJUST SINE ANO CCS FOR COMPUTATION OF HI IK) ANO UIIK) IF ( HUPIV.IPIVI - HIJPIV, JPtVl I 152.1S3.153 HTEMP = HIIPIV,IPIV)HIIPIV,IPIV) = HiJPIV,JPIV)HIJPIV,JPIV) = HTEMP RECOMPUTE SINE ANO COS HTEMP = SIGNF (1.0, -SINE) * COSINE COSINE = ABSF (SINE)SINE » HTEMP CONTINUEINSPECT THE IQS BETWEEN 1*1 WHETHER A NEW MAXIMUM VALUE THE PRESENT MAXIMUM IS IN THE I OR

ANO N-L TO DETERMINE SHOULD BE COMPUTEO SINCE J ROW.

200210230240250

00 350 I = 1,NM11IF (I-IP1V)210,350,200IF(I-JPIV)210,350,210IF I IQ I I)-IP IV1230,240,230IF( IQ 11l-JPIV)350,240,350K = IU ( I )HTCMP = H11,K>HI I, K) = 0•

6HCAGQ94 6HDAG095 6HOAG096 6HUAG097 6H0AG09B 6H0AG099 6H0AG100 6H0AGI 01 6H0AG102 6H0AG10 3 6HDAGL04 6H0AG105 6HDAG106 6H0AG1J7 6H0AG108 6H0AG109 6H0AG110 6HUAG111 6H0AG112 6H0AG113 6HCAG114 6H0AGI15 6HDAGI16 6HDAGI17 6hCAG118 6H0AG119 6HDAG120 6HUAG121 6HCAG122

Page 277: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

IPLl-I+l 6HDAG123XII) >0. 6HDAG124c 6H0AG125c SEARCH IN DEPLETEO ROW FOR NEW MAXIMUM 6HDAG126c 6H0AG12700 320 JMPLl.N 6HDAG128. IF I XII>- ABSFI KII.JIl 1 300,300,320 6HDAG129300 XIII *> ABSFIHI I,J) I 6HDAG130IQU) = J 6HDAG131320 CONTINUE 6HDAG132H(I,K)=HTEMP 6HDAG L 33350 CONTINUE 6HDAG134C 6HDAGI35XIIPIVI *0. 6H0AG136X(JPIV) *0. 6HDAG131C 6HDAG138C CHANGE the other elements of h 6HDAG139C 6HDAG14000 530 1*1,N 6HDAG141C 6HDAG142IFII-IPIV1370.530.420 6HDAG143370 HTEMP * H(I.IPIV) 6HDAG144Htl.lPIV) * COS INE*HTEMP ♦ SINEYHII,JPIV) 6HDAG145IF ( XII) - ABSFI HIl.IPZV)1 1380,390,390 6HDAG146380 Xll) = ABSFIHU .IPIV)) 6HDAG14710(1) = IPIV 6HDAG14B390 HI I,JPIV) » -SINE*HTEMP ♦ COSINE*HII, JPIV) 6HDAG149IF ( XU) - ABSFI HU,JPIV)) ) 400,530,530 6HDAG150400 XU 1 = ABSFIHI I, JPIV) ) 6IIDAG1 5 IIQtl) = JPIV 6IIDAG15ZGO tO 530 6HDAG153C 6HDAG154420 IF II-JPIV)430,530,480 6HDAG155430 HTEMP * HIIPIV,I) 6HDAGI 56H( IPI V, I ) - COS INE*HTEMP ♦ SINE*HU, JPIV) 6HDAGI57IF ( XIIPIVI - ABSFI HIIPIV,I)) ) 440,450,450 6HDAG158440 XUPI VI = ABSFIHI IPIV, I 1) 6HDAGL 59ICUPIV) - I 6IIDAGI 60450 HI I,JPIV) » -SINE*HTEMP ♦ COSINE*HU,JPIV) 6H0AG161IF ( XII) - ABSFI HU,JPIV)) ) 400,530,530 6HDAG162C 6HDAG163480 HTEMP * HIIPIV.I) 6HDAG164HIIPIV,I) = COSINE*HTEMP ♦ SINE*H<JPIV,I) (SHDAG165IF ( X(IPIV) - ABSFI HIIPIV,!)) ) 490,500,500 6HDAG166490 XIIPIV) = ABSF(HIIPIV,I)1 6H0AG167IOUPIV) = I 6HDAG168500 HIJPIV.I) » -SINE*HTEMP ♦ COSINE*H(JPIV,I) 6HDAG169IF 1 X(JPIV) - ABSFI H(JPIV.I)) I 510,530,530 6H0AG170510 X(JPIV) = ABSF(HIJPIV,I)) 6H0AG171ICIJPIV) * I 6H0AG172530 CONUNUE 6H0AG173C 6HDAG174C TEST FOR COMPUTATION OF EIGENVECTORS 6H0AGI75C 6II0AG176IFUEGEN .EG. 0)540,40 6HDAGI77540 DO 550 1=1,N ■ ! 6HIJAG1 78HTEMP=U(I, IPIV) 6HDAGI 79Ull, IPIV) = COS!NE*HTEMP + SINE*U(I.JPIV) 6HDAG1B0550 U( I , JPIV)=-SINE*HTEMP + COSINE*UI k*JPIV) 6HDAG1UIGO TO 40 6HUAG1R2

1000 RETURN 6HDAGI 83END 6HDAG1U4

FUNCTION RACAH(A,B.Y,X,C,Z)C IFIC-A-B.LE.O.llGO TO 401 402 C0FJU=0.0 RACAH=0.• RETURN 401 IFCA-B-C.GT.O.IICO TO 402 IFIB-C-A.GT.O.l)G0 TO 402 IFIC-X-Y.GT.0.11G0 TO 402 IF (X-Y-C.GT.0.1IGO TO 402 IFIY-X-C.GT.0.1 IGO TO 402 IF(Z-X-B.GT.0.1)G0 TO 402 IFIX-Z-B.GT.O.MGO TO 402 IF(B-X-Z.GT.0.1IGO TO 402 IF(Z-A-Y.GT.0.1ICO TO 402 IF(A-Z-Y.CT.O.IIGO TO 402 IF(Y-Z-A.GT.O.IIGO TO 402413 NMAX* MINI (A*B-C,X+Y-C,A*Y-Z,B4X-Z»NMIN= MAXI (O..A-C+X-Z,B-C+Y-Z)

IFINMIN.LT.OICO TO 402SUM=0.COF JU = l •I X3 = A*B + X +Y+ 1 . 1 1 Y 3 = C + X + Y *■ 1 • 1 12C=C«C+.1 I Z 3= 12C +1 Z3 = IZ 3IX4=A+C+X-Z+t.l IZ5=Z+Z+1.1 Z5=IZ S 122=I 25-1 IY4=IX3-I2Z I Z4 = B + X-Z + 1.1 IR=A+B+C+1.1 R = IR1T=B+C-A*.l I R1=IY3 R1=IR1IR2 = X + 8 + Z + 1• I R2*IR2IR3=A+Y+Z+1.1 R3 = 1R 3 IT1*Y + C-X +.1 IT2=B+Z-X+.l IT3=Y+Z-A+.1SOI 00 414 I=NMIN,NHAX

IA3=IZ3+I IA4=IY4-1 IAS*I+1414 SUM* SUM+I-1.)**I*BICO(1X3—t«IY3l*8IC0(IY3,1A3)*BIC0(IA3,IX4I*BICOIIX4,IA4)*BIC0(IA4,IZ4)*B’CO(IZ4,IA5I*FL0AT(IA51 COFJU=CUFJU*SUM*SORT(Z3*Z5/(BICO(IR-l,I2CI*BtCOII2C,ITI*R*BICO1 <IR1-1, I2C)*BIC0(I2C,ITlI*R1*B!C0(IR2-1,I2ZI*BICO 112Z, IT2>•2 R2*BIC0(IR3-l,!2ZI*BICO(I2Z,IT3)*R3)I 502 INTEGE = 1X3-1506 COFJU*(-1. )**INTEGE*COFJU/SQRT(FLOATI IZ3*IZ51)499 RACAM=CUFJU INTEGE=IX3-1 D=(-ll**INTEGE racah=racah*dRETURNEND

f7 02

Page 278: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SJBRDJTINE SYMEISIA,N,C,JMLTMX.T.KNTRLl,KNTRL2) DIMENSION A(1) .C(1I,T(1) 003EIGENVALUES AND EIGENVEC TORS OF 4 REAL SYMMETRIC MATRIX 004N=ORDER 3F MATRIX A 005A=JP»ER TRIANGLE OF SYMMETRIC MATRIX TO BE 01AGDNALIZED 305A IS A LINEAR ARRAY, UPPER TRIANGLE ST0RE3 ROWWISE 007EIGENVA.JES ARE RETJRNE3 IN THE FIRST N LOCATIONS OF THE ARRAY A C = E I GENVECTDR MATRIX 008JMLTMX IS THE DIMENSIONALITY 3F C IN THE CALLING PROGRAMC<I,J>=I-TH COEFFICIENT OF J-Trt EIGENVECTOR 303T = 90 CHARACTERS 3F JOB TITLE<NTRLl=l FOR CALCULATION OF EIGENVECTORS, «D FOR NO CALCULATION <NTRL2=L FOR OUTPUT, =0 FOR NO OUTPUT

011IN0EXlI,N) = I«N-l l*t l -m/2»l <=(N*(N*1)1/2n oDO 53 1=1,N 03 53 J=l,I 11=11*11l = N*( J - l ) ♦!-( J*( J - l ) 1/2 53 CCI I I =41 IIIIFI<NTRl2.E0*1)CALL TRI3UTCC.N)

C GENERATE IDENTITY MATRIX 012NMIN = N-1 013IFKNTRLl. EO.OIGO TO 61 03 T3 1=1,N <=I-J“LfMX DO 73 J=1,N <=<*JMLTMX IF I I . EG.J)G0 TO 60 tIRIO.GO 10 7360 Cl 0 = 1.70 CONTINUE ^ 02961 IFIN.CT.l)GO TO 71N’JM = 3 GO TO 553 71 TRACEA=3.03 75 1 = 1,N M=IN3EX(I-1,N)7b TRACEA=TRACEA*4IM) 024C 025N J M = 3I ND = 3 AN3RI=0.C COMPJ T E NORMS 030DO 140 I=1,NMIN M= I ♦ 1NPR33=IN9EXII -1,M»-I DO 143 J = M,N NTEMP=NPR3D*J143 AN3RI=AN3RI*2.*A(NTEMPI*A(NTEMP» 036ANORI=SORTIANORII160 ANDR M = AnDRI 038AN3RF=<.5E-D8)*ANORIIFIANORF) 160,631,190 ' 1 040

C 041C COMMUTE THRESHOLD VALUE, SEARCH FOR ELEMENTS LARGER THAN THIS190 AvDRM=AvDRM/FLDAT(N)200 DD 530 < = 2,N

M»X-I NTEMP=X-N DO 530 1 = 1,M NTEM»=NTEMP*N-L*lIFIABSIAINTEMPM.LT.ANORMIGO TO 530I ND= 1C PIVDT ELEMENT FDUND, COMPUTE SINE ANO COSINE OF. ROTATION ANGLEXLAM=-AINTEMP>N?R30=IN0EX(L-1,N)N0JD=INJEX(X-l,N)XMU=.5*< A INPROOI-AIN3UO))3MEGA=XLAM/(SORT{XLAM*XlAM*XMU*XMU))1FIXMU.LT.0.)OME GA=-OMEGASINE>DMEGA/S3RT(2.*(l.*S3RTI1.-OMEGA*DMEGAII)CDSI=S3RT(1.-SINE*SINE)CC ROTATE L-TH AND K-TH COLUMNS AND ROWS WHERE PIVOT IS AINTEMPIDO 423 1=1,N IF I I.E3.LIGD TO 420

I F ( I - < ) 347,420,343 343 NX = N3J0M-KGO TO 348347 N< = INDEXII-1,N)*K-I348 IFII.ST.DGO TO 353 NL=INOEXIl-l,NI*L-I GO TO 354353 NL * NPROD*I-L354 r EMP = A( NLIA(NLI=TEMP*C3SI-A(NXI*SINE At NX I=TEMP*S1NE»A«NX)*C3S1 423 CONTINUE C IFKNTRLl.EO.OIGO TO 425 M4TRDN=(L-1)*JMLTMX MANAGE = K-1>*JMLTMX00 424 1=1,N M4T RDN = MATR0N*1 MAN4GE=MANAGE*1 TEM?=C(MATRON!ClMATRDNI=TEMP*COSI-CIMANAGE)*SINE424 C(MANAGE)=TEMP*SINE«-C(HANAGE»*C3SI425 NJM=NJM*1 SINCDS=SINE*COS!SINS3=SINE*SINECOSS3=CDS1*COS!TEMP = A(NPROUI-AIN3U0)WDR<=2.*A(NrEMP)*SlNC0SSINE=4IN>R0D>AINPRDO)=SINE*COSSO*AIN3UOI*SINSQ-WORX AIN3JD)=S1NE*S1NS3*A(N3JO I*C0SS3*WORX AINrEMP) = TEM?*SINC0S*A(NTEMP)*IC0SS3-SINS0I 530 CDNTINJc C IF!IND.EO.OIGO TO 5401 ND= DGO TO 230 540 IFIANDRM.GT.ANORFIGO TO 190CC MOVE EIGENVALUES TO FIRST ROW OF MATRIX 601 NL = 1DO 6D4 1=2,N NL=NL*N-I*2

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Page 279: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

634 A(I)•AlML)CC WRITE OJT RESULTS653 IF(<NTRL2.EO.O)RETURNWRITE(6,66D)(TII), I»1,20),MUM 650 FORMAT! 1H3, 2DA4,6X, 3DHNUMBER OF ITERATIONS RSOUIREO , I3//15X,UHE llGENYAtJES)03 570 1*1,N 670 W RITE(6,630)I, A( I )680 F0RM4r(2X,I2,2X,E15.7>IFKNTRLI.EO.OIRETURN WRITEI6>1333)1003 F3RMAT(/.15x,12HEIGENVE;TORS/»■33 71 3 I = 1, M MAIR3'l=t 1-1>*JMLTMX Lj WER = MATR3MU LIMIr=MATR3M*N 710 WRITE(5,733)I,(G(J),J=LDWER,LIMIT)733 F3RMATIIX,13,7E15.7/(4X,7E15»7))RETJRNEmD

SJ8R3JTI NE READER! ISXIP)DIMENSION HFJPLSI12,12),HF1BOY 112 ,12) ,NM16 ) , MVALUE<2BI. B0Y211410>D3J3LE PRECISION HFJ»LS IF!IS<I?.E3.0)RETURM 03 1 XASE-l.ISKIP RE AD(4)HF1 BOV 00 3 J= 1,2 'Re AO I 4) MM 00 2 M=1,6 MAXIM=NM(M)IF(MAXIM.E0.3IG3 TO 2READ! 4 1 ( MYALUEI OUNT) ,K3UNT*l,MAXIM)L = (MAXlMMMAXIM*l))/2 READ!4)(C0V21(K), K>1, L)2 COMTIMJEIF(J.EO.1)READ(4)HFJPLS3 GONT!MUc I CONTINUEWRITEI6,2500)!S<IP 2500 FORMAT!25H1TAPE PROPERLY POSITIONEO,13 , 14H FILES SKIPPEO)RETURNEND

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Page 280: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

SUBROUTINE DIASRM(PRDBLMt NUMPAG,TITLES,NUMPLT,NUMBER.PLOT,JCOUNT,MDDUL,ISCALE,ITRUNK,TRUNK)DIMENSION PR0BLM(l>,TlTLESt5,l),PL0TIl),JCOUNTtI) , EQUAL!2>,LOCATE!2253),IARANGI200).GROUND(25)(PR33LM) IS A 80 LETTER TITLE, CENTERED ON TOP OF THE PAGE, AND (TITLES) ARE 2D LETTER NAMES ASSOCIATED hITH SUCCESSIVE PLOTS.THIS ROJTINE PRINTS (NUMJLT) ENERGY LEVEL D1AGRMS, SIDE BY SIDE,THREE TO A P GE, EACH OF (NJMPAG) PACES LONG. EACH DIAGRAM MUST CONTAIN THE SAME NUMBER (NUMBER) OF LEVELS. THE ENERGIES ARE IN THE ARRAY (PLOT). THE ROUTINE SORTS (PLUT) IN DESCENDING ORDER FOR EACH LEVEL DIAGRAM, ANO RETURNS (PLOT) ANO (UCOUNT) THJS OILREARRANGED. THE ROUTINE SCALES TO (NUMPAG) PAGES, AND PRINTS THE 015ENERGY AND (1) 3JANJJM NJMJtR (JCOJND ASSOCIATED WITH EACH LEVEL. DliIF IMOOJL)= 0 THE OJANTJM NUMBERS ARE INTEGER, ANO 1= UNITY THE 017OJANTJM NJM3ERS ARE HALF INTEGER. IF TWO (OR MORE) LEVELS FALL AT 013THE SAME LOCATION, ALL THE OUAnTUM NJMU-RS ARE LISTED.(jcojnt) should contain twice he ojantjm numbers if they are 1 /2 023INTEGER. IF (ISCALE) - 1,2 THERE ARE SEPARATE SCALES FOR EACH DIAGRAM WITH 2 3EING ADJUSTED TO ZERO. IF (ISCALE) = 3,A,5 THERE IS ONE SCALE FOR ALL DIAGRAMS, WITH A HAVING ONE ADJUSTMENT To ZCRO, AND 5 HAVING SEPARATE' ADJUSTMENTS TO ZERO.SETTING IITRJNK) EUJAL TO JNITY ALLOWS GUTTING OFF THE SPECTRUM ANDAOJJSTING THE SCALE TO A MAaIMuM EXCITATION OF (TRJNK)LEVELS MAY 3E DELETED FROM THE DIAGRAMS BY SPECIFYING IJCOUNT) «7777, 3JT THE ARRAY (PLOT) FOR THESE LEVELS SHOULD BE WITHIN THE RANGE OF THE LEVELS TO 3E PLOTTEDDATA PLJS/1H*/,DVRPLD/H3/,EQUALI1>/1H»/,EQJAL(2)/9H«--*/, .PARENl/H(/,PARcN2/lH)/IT AP E = 3 REWIND ITAPE IC0JNT=NJMBER*NJMPLT MANA3EOSKIP=NJMPAG*66-121SK1P-SKIPM.ICC ARRANGE EIGENVALUES IN PLOT IN DESCENDING ORDER KK- - 1IFINJMBER.GT.DGO TO 300WRITE I6,2009I3VRFLD,PLUS,PLOT!1)RETURN300 DD 3 K-l,ICOUNT,NUMBER D69KK=KK«NJMBER91 N= <93 IF(»LOT(N).GE.PLOT(N*1))3D TO 92x=plotin)PLOT!N)«PLOT(N»l). PLOT!N * 1 ) = XI-JCOUNTIN) / Njcojntini- jcountinm)JCOJNTIN»1)«I IFIN.E3.OGO TO 92 N = N-l GO TO 93C 19892 IFIN.ED.KOGO TO 8N = N*1 ' 200GO TO 9J 8 CONTINUE1FIISCAlE.LT.3130 TO 305 202

ENMAX-PLOTI I)ENMIN-PLOTI NUMBER)DELTA-0.KK-0DO 7 K-l,ICOUNT,NUMBER KK-K <.NUMBERIF!ISCALE.NE.5)30 TO 190 EDELTA-PLDTIKI-PLOTIKK)DELTA-AMAXK EDELTA.OELTA)GO TO 7190 ENMIN = AMINl(ENMIN,PLOTKKI)ENMAX=AMAXUENMAX,PL0T(K) )7 CONTINUEIF!ISCALE.NE.510ELTA-ENMAX-ENMIN DELTAI=DELTAIFIITRJNK.E3.1.AND.DELTA.GT.TRUN.KIDELTA-TRUNKINTERPOLATE TO FIND THE LINE POSITIONS 305 KKODO 9 I-l.NUMPLT X-KKUKK-XX.NJMBERGO TD (191,192,193,199,195),ISCALE191 ADJJST-»LOT(K)OELTA-AOJJST-PLOTIKX)IFIlTRUNK.NE.l.OR.DELTA.LE.TRUNK)GO TO 196DELTA-TRJNKAOJJST=?LDT(K<)*DELTA.GO ro 196192 ENMIN=PLOT(KK)DELTA=PLOT(K)-ENMINIF! I TRUNK.EO.l.ANO.DELTA.GT.TRUNK)DELTA-TRUN<ADJJST-DELTA GROJNDII)= ENMIN GO TO 196193 ADJJST-EN.MAXIF!I TRUNK.ED.1.AND.DELTA1.GT.TRUNK)AOJUST-ENMIN»TRUNK GO TO 196 199 ADJJS T = DEL T A GO TO 195195 AOJJST-DELTA ENMIN-PLOTIKK)GROJNDII)=E NHIN196 DO 9 J = < , K K IFUSCALE.NE.1.AND.ISCALE.NE.3)PL0T(J)-PLOT IJ)-ENH!N ENERGY-AOJUST-PLOTI J)I FI ENERGY.LT.O.)ENERGY-0.IF!JCOJNTIJ) .ED.7777IG0 TO 10 LOCATE! J )=ENER&Y*SKIP/DELTAM.l GO 10 9 13 LOCATEIJI-O.9 CONTINUE

130 I 1 -MANAGE♦1 .I2=MANAGE*NUMBER*1I3=MANAGE*2*NUM3ER»1KONTRL-1WRITE I 6,1031 I(PROBLMIIJ<),IJK-1,201 IDDl FORMAT!HI,12X.2DA9)IF!ISCALE.E3.9I WRITE I 6,2001IE3UALI1),ENMIN 2001 FORMAT!99X,13HGROUNO STATE , Al, IX,E12.5) IF(ISCALE.NE.9)WRITE(6,13D2)

Page 281: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

DO 5 J = l ,3IFI IC3JNT.Ea.MANAGE*J*NUN8ER>50 TO 55 CONTINJ:J * 36 I=MAN4SE/NUN8ER*l L = I ♦ J -1WRITE(6,1332)((UTLES(LI,12) ,L1-1,5>. LZ-I,L>1332 FORMAKIX,3(3X,5A4,20X))33 TD <2,3,2,4,3),ISC4LE2 «RITE(6,(002)33 T 3 43 WRITE(6,1333)(E3JALI1),3ROJNDU2>,12=I, L)1333 FORMAT! IX,313X,7HGR3UNO ,41, E12.4,23X))4 WRITE(6,1032)CC PL3T I HE SPECTRAITESTO03 13 J=1,!S<!P53 IF(J.NE.L3CATE(I1))G0 TD 11 <1 = 3

111=11 i rem3 = 1103 54" X3-1,NUMBER IF(!ll.E3.MANAGE*NUM3ER)33 TO 12 111=111*1i f(l3:4te( i i ).E3.i.o: ate( i i i ) )30 ro 52 lFtLOCATEIIlD.EO.OIGO T3 54 53 T 3 12 52 <1 = <1 ♦ 1IARAnG(<1)=JC0UNT(I1)ITEST=111=11154 CONTIN JE

C 11 IFIL3CATEIIl).NE.0)WRITE(6,2003)3VRFL0,PLUS25 ISE r = 327 IF(l3:aTECI1).NE.0)33 T3 20 ISEI * I 11=11*1 53 ID 2728 IFIISET.E3.1IS3 TO 53 11=11-153 ID 152

C 12 IFII IESr.Ea.3IG3 TO 125 IF(<1.5T.8)53 TD 124 IF(M30JL.E3.l)G3 TO 123 >,wRir£I5,2333)3VRFLD,>LUS»PL3T{Il), E3UAL.(IAR4N3(X)»K=1«KI), JC 3UNT(II)2033 F3RMATCAl/4l,F9.4,Al,A4,9I3)53 13 15212 3 MRirE( 5. 2333>3VRFLD.»LUS,PL3T(Il),E3UAL,(IA»AM3«) ,X=1,K1),JCOUNT(ll)2033 FORMAT I 41/Al, F9.4 ,Al,44,IX,9 It 2 , lrt/))50 13 152124 WRITE IS, 3033)3VRFLO,, LJS»PL3T(I1)«E3U4L*P4REN1» KONTRL tPAREN2 3333 F3RM4TI41/41,F9.4,41,44,IX,41,12,41)WRITE!ITA?E)<1,IIARAN5(<),X=1,XI),JC3UNTill)ONI RL=X3NTRL*1 53 TD 152125 WRITE! 5, 2 33413VRFL0 ,3LUS, PL 3T(11).JCOUNTIIt)2334 FORMAT!41/41,F9.4,5M ,13)

097093099

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119

IFM3DUL.EQ.1)NRITE(6,2005)PLUS 2335 FORMAT!1A1.17X,2H/2)152 11-11*1 I TEST = 3153 IFIIC3JNT.LT.2*NUM8ER*MANA3E)33 TO 13 151 IF(J.NE.L0CATE«I2))53 T3 111XI =3 121=1203 154 0=1, NUMBER IFII2I.E3.MANASE*2*NUMBER)53 TO 120 121=121*1IFUDCATEI12).E3.LOCATE!121)ISO T3 155 IFIL3CATEI 121).£3.0)30 T3 154 50 T 3 123 155 Xl=Xl*lIARANSKll-JCOUNTI 12)HESr = l 12=121154 C3NTINUE111 (SET = 3112 IFIL3CATEI 12).NE.0)50 TO 128 I SET - 1. 12=12*1 GO 13 112 128 IF(ISkT.EQ.l)GO TO 151 12=12-1 GO 13 133120 IFIITEST.E0.0IG3 TO 225 IF(<l.Sr.8 )G0 T3 224 IF(K30UL. EO.I)G3 TO 223WRirE(6,2037)?LJS,PL3TI12 ) .EQUAL, IIARAN51X) , X-l, XI) . JCOJNT(12) 2007 F3RMAII1A1,43X.F9.4,AI,A4,9I3)GO T3 133223 WRITEI6,2337)PLJS,PL3T(I 2 ) ,EQUAL, 11ARAN5(X) , K=1, XI) •JCOUNT( 12)2337 FORMAT!IA1.43X.F9.4,A1,A4,IX,9(12,1H/))GO TO 130224 WRITE(S, 3037)PIJS,PLOT!I 2 ) ,EQUAL,PAREN1, K3NTRL,PARENZ 3337 F3RMAI(1A1,43X,F9.4,A1,A4,IX,A1,I2,A1)WRITE! ITAPE)<1,(IARANG(X),X-I,XI), JCOUNT(12)ONTRL = X3NTRL*l GO T3 133225 WRITE(6,2308)PLJS,PL3I(12),JC3UNT(1212338 FORMAT!1A1,43X,F9.4,5H------- ,13)IF IMOOUL.EO.l)WRITE(6,2039)PLUS2339 FORMAT!141,SOX,2H/2I133 12=12*1 HESr = 0453 IF(IC0JNT.LT.3*NJMBER*MANA5E)50 TO 13 451 IFIJ.NE.LOCATE!13))G3 13 411

Xl = 3 131=13 IrEMP=I3DO 454 <3=1,NUMBERIFI I3I.E3.MANAGE*3*NUMBER)G3 TO 420131=131*1IFIL3C4TEI13).EO.LOCATE!1311)G0 TO 455 IF(L3CATE(131I.EO.OIGD 13 454 GO 10 420

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Page 282: TO MY FAMILY · dicted and experimentally observed states of the nucleus. They do, however, give qualitative explanation to the low- energy excited nuclear configurations found to

455 KI«<1*1IAR4N5(<1)=JC0UNTII3>ITEST=1 13=131 454 CONTINUE411 ISET=0412 IFILOCATEt13).NE.0)50 TO 428 ISET=113=13*1 GO TO 412 428 IF( ISET.EO.HGO TO 451 13=13-1 50 TO 430

: 420 1F(ITEST.EO.OJGO TO 425 IF(<1.3T.8)50 TO 424 IFMOOUL.EO.DGO TO 423wRirE(S,2010)PLJS,PLOT(13)•EQUAL,( IARANS!K),K*1,K1)tJCOUNT( 13)2010 FORMAT!1A1,86X,F9.4,A1.A4,913)30 TO 413423 WRITE(6,2310)PLJS,PL0T(I 3 ) ,EQUAL,( IARANOiK),K>1 ,K1) , JCOUNT! 131 2310’F0RN4T(141,B6X,F9.4,41,A4,IX,9(12,14/))30 TO 410424 WRITE I 6,3010)PLJS, PL3T( I 31, E0U41, P4RENl, KONTRL,PAREN2 3010 FORMAT!lAlf86X,F9.4,Al,A4,lX,Al,12,Al)WRirE(irAPE)<l,(IARANa(X),< = l ,Kl) .JCOUNT11 3)<ON!RL = ONTRL*1 30 !0 413425 wRITE(St2011)PLJS«PL01(!3),JCOUNT!! 3)2011 FORMAT!1A1,B6X,F9.4 ,5H ,13)IF(MOOJL.E3.1)WRITE!6,5450)PLUS5450 F0RMATI1A1,103X,2H/2IC 430 13=13*1 IT ES T = 0 13 CONTINUEMAN43E=MAN43E*3*NUM3ERWR1TE(S,1001)IF! ONTRl. £0.1)30 TO 575 REWIND ITAPE<ONT RL = ONTRL-1 00 500 !NDEX = 1, ONTRLREAD!(TAPEIK1,!IARAN3(K)*K»1*X1)»KOUNT IHM0DJL.E3.DG3 TU 550WRITE(b.4000)PARENl, I NOEX,PAREN2, 11ARAN3(X) , K=1,Kl>,KOUNT 4000 FORMAT!IX,Al,12,41,3513/I5X,3513))30 TO 500553 WRI!E(6,4030IPAREN1,INDEX,PAREN2,!IARAN3!K),K*l,Kl), KOUNT 4030 FORMATI1X,41,12,41,23(13,2H/2)/(5X,23!I3,2rl/2)))500 CONTINUE

c '57S IF!ICOJNT.ST.MANAGE)50 TO 100 RETJRN ENO

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