Primary Beam Fragmentation

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0

N (A-Z)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Z

r-processpath

rp-processpath

RI yield in ions/s

>1012

1010

108

102

1

.01

10-4

10-6

106

104

Region ofKnown Nuclei

Light target

RISING ACTIVE STOPPER BEAM SETUP: DECAY SPECTROSCOPY OF SECONDARY BEAM AFTER IMPLANTATION on DSSSD ARRAY. IMPLANTATION –ββββ-DECAY CORRELATION

The Rising Active Stopper 2007 GT ββββ-decay GSI-FRS campaign in A≈50-60

S4

A.Gadea IFIC-CSIC, Spain & INFN-LNL Italy

For the S326 and S316 RISING collaborations

GSI-FRS

Investigation of T=0 proton-neutron pairing in the Gamow-Teller ββββ-decay of the TZ=-1

62GeA.Gadea (INFN-LNL and IFIC-Valencia), A.Algora (IFIC- Valencia),

E. Grodner (INFN-LNL and HIL-Warsaw)

J=0 T=1

J>0 T=0

Pairing is a fundamental concept in

nuclear physics. Since long 62Ga is contemplated as a candidate for high spin

phenomena related with T=0 pairing.

Through the 62Ge GT β-decay it is possible to explore also T=0 pairing properties of low-lying 62Ga states.

Early hint of p-n pairing: the Wigner

effect in mean-field

mass formula

mass deffect within mean-field

Superallowed GT ββββ-decay and proton-neutron condensate: the SU(4) supermultiplet

In the case of some light nuclei, the considerable GT strength can be explained by the Wigner SU(4) symmetry. SU(4) symmetry is heavily broken by the spin-orbit splitting of the single particle states �fragmentation of strength .

Tz=-1

Tz=0

Tz=+1

T=1

S=0

T=0

S=1

62Ge

62Ga62Zn

F

GT

F

γ

Suggested the possibility that SU(4) symmetry is partially restored by p-n pairing forces. Thus large GT strength to low lying T=0 1+ states in odd-odd N=Z nuclei could be a fingerprint of T=0 p-n pairing

F. Iachello, YCTP-N13-88 (1988); P. Van Isaker, J. Phys.: Conf. Ser. 20 (2005)

N=ZN=Z

Boson space of correlated Boson space of correlated

nucleon pairs in IBMnucleon pairs in IBM--44

6262Ga N=3Ga N=3

F. Iachello, Proc.Int. Conf. on Perspectives for the IBM, Padova p.1 (1994).F. Iachello, Yale University preprint YCTP-N13-88 (1988).

F. IachelloP Van Isacker, J. Phys. Conf. Ser. 20 (2005) 131

Pseudo-SU(4) (fp-shell ���� sd-shell)

62Ge 83ms

62Ga 116ms

58Zn

29

30

31

32

1.9 1.95 2.0 2.05 2.1

62Ge

Ga

Zn

FRS: 62Ge 2.5 x 104

Total “correctly”implanted 62Ge:1.9 x 104

Surviving Implantation:1.6 x 104

A/q

Z

Sort by: E. Grodner INFN-LNL and HIL-WarsawJ. Grebosz IFJ-PAN Cracow, A.Gadea IFIC-Valencia

Fragmentation

of primary 78Kr

750MeV . A

~ 4×108 ions/s 9Be 4g/cm2

target

Analysis with a

customized

version of Spy

and Cracow by

J.Grebosz

FRS - S4 + implantation in

DSSSD Active Stopper: Survival

probability for 62Ge = 84%

Efficiency of the

DSSSD Active

Stopper for β-decay positrons. The first 40ms excluded:

51%

Gate on 62Ge FRS+implantation Selected two sequential decays after implantation i.e. decay of 62Ga following the decay of 62Ge.

62Ge Lifetime Determination

T1/2=82.9 ± 1.4 msE. Grodner INFN-LNL and HIL-Warsaw

Fit 40-1000 ms

exclu

ded

Identify transitions in 62Ga

3.9

%

2.1

%2.2

%

2.1

%

3.5

%

1.8

%

62Ga

T=1 0+

62Ge

T1/2=82.9 (14) msQEC=9.76(14) MeV

1017,4

4.75 ± 0.15 0.070

4.91 ± 0.15 0.050

4.88 ± 0.15 0.054

4.84 ± 0.13 0.059

4.36 ± 0.17 0.17

4.54 ± 0.17 0.12

Log ft B(GT) gA2/4ππππ

Apparent Log ft ���� B(GT) ≤ given value

+0.017-0.017

+0.015-0.017

+0.013-0.019

+0.016-0.022

+0.05-0.05

+0.03-0.05

First 1+ known

form LNLLNL--GASP GASP

inin--beam study beam study

D.Rudolph D.Rudolph

PRC69(2004)PRC69(2004)

034309034309

Shell model Calculations for the 62Ge GT ββββ-decay

I.Petermann,G.Martínez-Pinedo,K.Langanke,E.Caurier Eur.Phys.J.A34,319–324(2007)

KB3G interaction

full fp-shell

model space

P.Sarriguren private P.Sarriguren private

communication and communication and

P.Sarriguren et al. P.Sarriguren et al.

PRC 64 (2001) 064306PRC 64 (2001) 064306

Preliminary QRPA Preliminary QRPA

B(GT) calculations B(GT) calculations

with with Skyrme (SG2) Skyrme (SG2)

interaction, interaction, ββ~0.2~0.2

No GT hindrance No GT hindrance

factor included.factor included.

26

54

28 Ni 2854

26 Fe

27

54

27 Co

0+

Tz=-1

T=1

0+

Tz=0

T=1

0+

Tz=+1

T=1

β+ (p,n)(3He,t)

If isospin symmetry works these

two mirror processes should be

identical

The main idea of this work was to test if

isospin symmetry is good enough

to justify the combined analysis

Study of Tz=±±±±1 Into Tz=0 GT transitions in the f shellB. Rubio (Valencia), Y. Fujita (Osaka) and W. Gelletly (Surrey)

Analysis F. Molina (Valencia)

∑=

+=GTi

iFermittT

111

2/1

From

β-decay

B(F)=

N-Z

From

(3He,t

)

Y. Fujita… et al.

PRL 95 (2005)

N=Z

Z=28

Z=20

N=28

N=20

Luckly enough we have all

Stable targets in the f shellβ+ and β- or CE reactions

B. Rubio, Osaka 31 Jul 2009

(3He,t) CE Reactions @ RCNP(Osaka)

ββββ+ decay of Tz=-1 RISING + ACTIVE STOPPER @ GSI-FRS

Ex in daughter nuclei (MeV)

Co

un

ts

0 2 4 6 8 10 12

Charge Exchange Reactions Results (RCNP-Osaka)

HIGH RESOLUTION!!!

0

1000

2000

3000

2000

4000

6000

1000

2000

3000

500

1000

1500

42Ca(3He,t)42Sc

46Ti(3He,t)46V

50Cr(3He,t)50Mn

54Fe(3He,t)54Co

g.S

(IA

S)

g.s

.(IA

S

)

g.s

(IA

S

)g.s

.(IA

S)

16F

g.s

.

0.1

93

0.4

24

12N

g.s

.

12N

0.9

60.

0.6

11 (

1+

)0.9

94 (

1+

)

1.4

33 (

1+

)

2.4

61 (

1+

)

2.6

99 (

1+

)

2.9

78 (

1+

)

3.8

70 (

1+

)

0.6

52 (

1+

)

2.4

11 (

1+

)

2.6

94 (

1+

)

3.3

92 (

1+

)

3.6

54

(1+

)

0.9

37 (

1+

)

4.5

50 (

1+

)4.8

28

(1+

)

3.8

95

(1+

)

3.3

77 (

1+

)

5.9

21 (

1+

)

4.3

32 (

1+

)

5.7

28 (

1+

)

3.6

89 (

1+

)

T. Adachi et. al.,

PRC 73, 024311 (2006)

Y. Fujita et. al.,

PRL 95 212501 (2005)

T. Adachi et al., NPA 788, 70c (2007).

Y. Fujita et. al.,

PRL 95 212501 (2005)

50Fe

54Ni46Cr

42Ti

A/QA/Q

A/QA/Q

ZZZ

Z

~1 million counts

~5.8 millions counts

~2 millions counts

~4.8 millions counts

Tz=−1 Nuclei of Interest Identify at GSI-FRS

Beta Decay Results and comparison with CEA=54, T=1

First 4th GT States till 4.5MeV were seen by beta decay

937 (

1+

)

937 (

1+

)

3377 (

1+

)3377 (

1+

)

3895 (

1+

)3895 (

1+

)

4550 (

1+

)

4828 (

1+

)

5921 (

1+

)

4550 (

1+

)

B. Rubio, Osaka 31 Jul 2009

A=50, T=1

First 4th GT States till 3.3 MeV were seen by beta decay

652 (

1+

)

2411 (

1+

)

2694 (

1+

)

3392 (

1+

)3392 (

1+

)

2694 (

1+

)

2411 (

1+

)

652 (

1+

)

3654 (

1+

)

4332 (

1+

)

5728 (

1+

)

0+

1

+

A=46, T=1

All the GT States were seen by beta decay

994 (

1+

)

1433 (

1+

)

2461 (

1+

)

2699 (

1+

)

2978 (

1+

)

3870 (

1+

)

994 (

1+

)

1432 (

1+

)

2460 (

1+

)

2697 (

1+

)

2978 (

1+

)

3870 (

1+

)

Results: preliminary BGT values from beta decay

Francisco Molina

Analysis in progress IFIC(Valencia)

A=54 B(GT) decay B(GT) CE

937 keV 0.471(55) 0.493(62)

3378 keV 0.074(14) 0.079(11)

3889 keV 0.064(17) 0.103(14)

4544 keV 0.075(27) 0.147(20)

A=50

652 keV 0.547(90) 0.510(14)

2404 keV 0.126(23) 0.151(40)

2685 keV 0.090(19) 0.106(28)

3380 keV 0.281(55) 0.350(93)

A=46

994 keV 0.330(329) 0.368(44)

1433 keV 0.107(107) 0.122(15)

2462 keV 0.146(146) 0.201(24)

2698 keV 0.111(111) 0.205(25)

2978 keV 0.479(478) 0.625(75)

3870 keV 0.105(119) 0.117(14)

Large B(GT) uncertainties are due to the errors in the beta decay half-life. A better value should come from the present experiment.

Isospin symmetry works in general (full strength) but some differences appear at high excitation energy, which should be understood

This is the first experimental testof BGT gs symmetry in the f shell. These cases are specially “clean” since they

involve only

ππππf7/2 to ννννf7/2and

ππππf7/2 to ννννf5/2

kind of transitionsand we compare only the two gs states

On behalf of the S326 and S316collaborators thanks to all the RISING, ACTIVE STOPPER, FRS and GSI -accelerator division Colleagues