Stephen Lars OlsenSeoul National University

February 10, 2014

A New Spectroscopy of Hadrons

High-1Gangwando

Through a theorist‘s mind

Visions of hadrons

What is seen by an experimenter

multiquark states from diquarks & diantiquarks

magentaanti-triplet

_ 3

_ 3

_ 3

yellowanti-triplet

cyananti-triplet

d

d d

d

d

u

u

u

u

u

uss s s s s

us

d

du

s

d

H-dibaryon

(anti-green) (anti-blue) (anti-red)

red-blue diquark green-red diquark blue-green diquark

uu

d

ds

Pentaquark

_

uccd

tetraquark meson_ _

magenta-cyan-yellowcolor singlet 6-q state

magenta-cyan-yellowcolor singlet 5-q state

green-magentacolor singlet 4-q state

(anti-green)

“exotic” hadrons that particle theorists love

multiquark states from “molecules”

H-dibaryon

uu

d

ds

Pentaquark_

c

uc

d

p,s,r,w

_

_

D

D*

p,s,w

us

d

us

d

s,w

tetraquark meson

L

L

N

K

baryonium

uu

d

uu

d

p,s,w

p

p_ _

__

_

“exotic” hadrons that nuclear theorists love

Non-qq mesons or non-qqq baryonspredicted by `QCD-motivated’ models

u cuc c c

u du

sd_

___

u d

usds

_u c

uc

__

_p

D0

D*0_

pentaquarksglueballs H-dibaryon

diquark-diantiquarks hybridsmolecules

_

Where are they??

non-qq & non-qqq color-singlet combinations_

The XYZ quarkonium-like mesons

Charmonium spectrum

Any meson that decaysto a c and c quark shouldfit in one of the (gray)unassigned states.

XYZ charmoniumlike mesons

1+(-)

0-+

0++

1++

Zc(3900)+ 3899 ± 6 46 ± 22 1+(-) Y(4260)p-(p+J/y)

0-+

0+(+)/1—(+)

0+(+)/1—(+)

cc assignments for the XYZ mesons?_

no unassigned levels forthe 1- - Y(4260) & Y(4360)

the X(3940) & X(4160) asthe hc(3S) & hc(4S) wouldimply huge hyperfinesplittings for n=3&4

the Y(3915) mass andG(YwJ/y) are toohigh for the cc0(2P).Also, no sign of YDD

the (4) charged Zsmust have a minimalquark content of ccud_

the X(3872) is a longcomplex story

_

_

the Y(4260)

s(e+e- hadrons)

Ecm (GeV)BaBar PRD86, 051102

M(p+p-J/y) (GeV)

found by BaBar in e+e- gISRp+p-J/y

Y(4260) p+p-J/y confirmed by BelleBelle PRL99, 182004

Y(4260) peak in s (p+p-J/y)occurs at a dip in s(D(*)D(*))

G(p+p-J/y) is large,10~100 × charmonium

e+e- gISRp+p-J/y

No sign of Y(4260) D(*)D(*)

M(p+p-J/y) (GeV)

BESII PRL88, 101802

Ecm (GeV)

X. H. Mo et al., PLB 640, 182

e+e- hadrons

Is there a b-quark version of Y(4260)?

BB

BB*

B*B*

e+e- hadrons

Ecm (GeV)

e+ e- h

adro

ns

e+ e- p

+ p- J/y

e+ e- p

+ p- ϒ(1

S)

?p+p-ϒ(1S)

e+e- p+p-J/y

_

Is there any anomaly in(4S,5S) p+p- (1S) ?

“bottomonium” bb mesons

2MB = 10358.7 MeVϒ(4S

)

p+p-

G(4S)p+p-(1S) G”(5S)”p+p-(1S)

2S3S

4S

(4S) (1S) p+p-

477 fb-1

52±

10 e

vts

Belle: PRD 75 071103

Signal

23.6 fb-1Belle: PRL 100 112001

325±

20 e

vts

parent N(p+p-(1S)) G(Y4Spp1S) Gtheory

(4S) 52±10 1.75 ± 0.35 keV

1.47±0.03 keV

“(5S)” 325±20 590 ± 110 keV <1.5 keV

Lum ~1/20th

σ ~1/5th Signal ~×6

“5S”4S

3S2S

“(5S)” p+p- (1S) ?

Υ(1S)π+π-

Υ(2S)π+π-

Υ(3S)π+π-

M2(π+π-)

M2(ϒ

π±)

M2(ϒ

π±)

M2(ϒ

π±)

π+π-

π+π-

“(5S)” p+p- (1S) ?

M(ϒ(1S)π±)

Υ(1S)π+π-

Υ(2S)π+π-

M2(ϒ

π±)

π+π-

π+π-

Υ(3S)π+π-

M(ϒ(3S)π±)

“(5S)” p-Zb1,2+

p+ (1,2,3S)

(3S)

(2S)

(1S)

M((nS)π+)max

p+

10,6

10 M

eV10

,660

MeV

Belle PRL 108, 122001 (2012)121.4 fb-1

JP of the Zb states

JP of the Zb states

19

Belle PRELIMINARY

Zb(10610)M=106082 MeV

G=18.42.4 MeV

Zb(10650)

M=106532 MeV

G=11.52.2 MeV

Belle PRL 108, 122001

Summary of parameter measurements

mB+

mB*

2mB*

March 2012bd

bd

B

B*

B-B* & B*-B* molecules??B

B*

b

b

_

B-B* “molecule”

B*

B*

b

b

_

B*-B* “molecule”_ _

_ _

Zb(106010)± Zb(106050)±

MZb(106010) –(MB+MB*) = + 3.6 ± 1.8 MeVMZb(106010) –2MB* = + 3.1 ± 1.8 MeV

Slightly unbound threshold resonances??

M=10608.11.7 MeVG=15.52.4 MeV

M=10653.31.5 MeVG=14.02.8 MeV

PDG: MB + MB* = 10604.50.6 MeV MB* + MB* = 10650.2 1.0 MeV

Belle:

_ _

Zb(10610)BB* & Zb(10650)B*B*_ _

Zb(106010)± Zb(106050)±

M(B*B*)_

M(BB*)_

“(5S)” p-(BB*)+_

“(5S)” p-(B*B*)+_

Bf(Zb(10610)BB*

Bf(Zb(10610)p+(bb)

_

_ =6.1±0.4 Bf(Zb(10610)B*B*

Bf(Zb(10610)p+(bb)

_

_=2.8±0.4

Belle arXiv:1209.6450

Are there c-quark versions of Zb’s

Is there a b-quark equivalent?

Y(4260) discovered

Yes, & it decays to Zb states

Are there c-quark versions of Zb’s?

???

run BEPCII/BESIII as a Y(4260) factory

Belle PRL99, 182004

BESIII: arXiv:1303.5949 s(e+e- p+p-J/y) = (62.91.93.7) pb

e+e- gISRp+p-J/y

TypicalJ/y +-e+e- p+p-J/y

@Ecm=4260 MeV

Y4260

J/y p+

p-

e+ e+

Y(4260)p-Zc(3900)+ p+J/y

Mass = (3899.0±3.6±4.9) MeV

Width = (46±10±20) MeV

Fraction = (21.5±3.3±7.5)%

BESIII: PRL 110, 252001

Significance >8s

p+

p-

26

Zc(3900) confirmed by Belle

Mass = (3894.5 ± 6.6 ± 4.5) MeVWidth = (63 ± 24 ± 26) MeVFraction = (29.0 ± 8.9)% (stat. err.

only)

Belle: PRL 110, 252002

p-

Mass = (3883.9 ±1.5 ±4.2) MeV

Width = (24.8 ±3.3 ±11.0) MeV DD*/p+p-J/y = 6.2 ± 1.1 ± 2.7

Y(4260)Zc DD*

Y(4260)p-Zc(3900)+

DD*_D0D*+

D+D*0_

_

_

BESIII PRL 112, 022001 (last month)

D*+

D0

_

Significance >18s

_

JP of the Zc(3900)?

e+ e-

p-

Zc

JPC=??

JPC=0-

initial state:

€

J;Jz = 1;±1 P = −1

final state: p Zc

0- 0+ forbidden by Parity ---

0- 0-

0- 1+ flat

0- 1-

€

L;Lz S;Sz

€

1;±1 0;0

€

0;0 1;±1

€

1;±1 1;0 − 1;0 1;±1€

dNd | cosθ |

€

∝ sin2 θ

€

∝1+ cos2 θ

JP=1-

JP=1+

JP=0-

The data clearlyestablish JP=1+

1;±1

BESIII data

q

Are there others?

Study Y(4260)p+p- hc decays

p+p-

BESIII PRL 111, 242001 (2 months ago)

sharp M(phc) peak but not near ~3900 MeV

M(p±hc)

ghc16 channels

g

hadrons

Y(4260)p+Zc(4020)-

Mass = (4022.9 ±0.8 ±2.7) MeV

Width = (7.9 ±2.7 ±2.6) MeV

fraction = 0.18 ± 0.07

no significant signal for Zc(3900)±p±hc

BESIII PRL 111, 242001

M(p±hc)

Fit results:

= 4017.3 ±0.3 MeV5.6 ± 2.8 MeV above D*0D*- thresh.

Zc(4020)

p+

p-

g

p-hc

hadrons

Does the Zc(4020)DD*? … D*D*?_ _

Zc(4020)DD*?_

D0D*+

D+D*0

_

_

4023

MeV

No sign of Zc(4020)DD*_

BESIII PRL 112, 022001

4023

MeV

BESIII arXiv:1308.2760

Mass = (4026.3 ± 2.6 ± 3.7) MeV

Width = (24.8 5 ± 5.6 ± 7.7) MeV

Fit results:

Something there (~10s!), but …

… higher mass (~1.5s) and width (~1.5s)than Zc(4020)phc signal

Zc(4020)D*D*?_

M(D*D*)

_

Zb & Zc mesons --“smoking guns” for non-qq mesons--

ubd

b decay to (nS) (J/y) must contain bb (cc) pair

electrically charged must contain ud pair

_

_

_

bb

b b

B0

B*+

dd

B0-B*+ ? ? Mixture?

ucd

c

Zb Zc

_

molecules?

€

12 (D*D * + D *D*)

€

12 (D*D * − D *D*)

€

12 (DD * + D *D)

€

12 (DD * − D *D)

€

12 (B*B * + B *B*)

€

12 (B*B * − B *B*)

€

12 (BB * + B *B)

€

12 (BB * − B *B)

CMS search for b-sector version of X(3872)

CMS: PLB 727 (2013) 57

€

pp → π+π

−Υ(1S ) + anything

(MB + MB*)-MU(1S)= 1144 MeV >> mw

(MD0 + MD*0)-My(1S)= 776 MeV < mw€

R = σ ( pp → X b →π +π −Υ(1S ))σ ( pp → Υ(2S )→π +π −Υ(1S ))

Relevant channel is ispin-conserving Xbw U(1S)

Y(4260) gX(3872)?

is this from Y(4260) decays?X(

3872

)X(

3872

)

X(38

72)

BESIII arXiv:1310.4101

Y(4260) gX(3872)? …cont’d

BESIII arXiv:1310.4101

X(3872)

Consistent with originating from the Y(4260)

All cm energies combined: 6.3s ~20 evt signal

Summary

QCD-motivated spectroscopies most favored by theorists do not seem to exist

- evidence for Pentaquarks has disappeared

- H-dibaryon with mass near 2mL is excluded at stringent levels

Numerous non-qq mesons not specific to QCD have been found

- Baryonium in J/ygpp at BESII and BESIII ??

- XYZ mesons containing cc and bb pairs

The JPC=1- - Y(4260) and “(5S)” have no compelling interpretation

- huge couplings to p+p-J/y (p+p- (nS)) not predicted in any model!!

- strong sources of charged Zc (Zb) states with M near mD(*)+mD* (mB(*)+mB*)

- evidence for a strong Y(4260)gX(3872) transition

_

_

_ _

Y(4360)

Y(4660)

Y(4260)

Y(4008)

X(3872)

X(4160)

Y(3915)

Z(4430

)

Z 1(4050

)

Z 2(4250

)

Zc(3900)

Y(4140

)

Z b(1061

0)

Z b(1065

0)

Y(4274)

X(3940)

X(4250)

X(4630

)

Lots of pieces

Are they all from the same puzzle?

Back-up slides

Event in the Belle Detector

The “XYZ” mesons

Zb1(10610) 10,607±2 18±2 1- p±ϒ(1,2,3S)/hb(1,2S); BB* `ϒ(5S)’p±Zb1

Zb2(10650) 10,653±2 12±2 1- p±ϒ(1,2,3S)/hb(1,2S);B*B* `ϒ(5S)’p±Zb2

43

“Old” hadron spectrosopy1964 The constituent quark-parton model was proposed independently by Gell-Mann and Zweig. Three fundamental building blocks 1960’s (p,n,l) Þ 1970’s (u,d,s)

mesons are bound states of a of quark and anti-quark:

baryons are bound state of 3 quarks:

€

p + =ud π 0 = 12 (uu − dd ) π - = du

K + = us K 0 = ds K 0 = sd K − = su

€

p = uud n = udd Λ = uds

p = u u d n = u d d Λ = u d s

€

p− =du

€

L =uds

QPM Superseded by QCD in the 1970s:observed particles are color singlets

Λ= (uds) )( ud=-p

Mesons are color-anticolor pairsBaryons are red-blue-green triplets

3 primary colors white whitecolor + complementary color

blue-yellowgreen-magenta

red-cyan

QCD “diquarks” ?

s

ud

=s

ud

u

_ 3

antisymmetric anti 3-plet

du ud-

sd ds- su us-

dd uu

ss

du ud+

sd ds+ su us+

symmetric 6-tet

6

3 3 = 3 6_

Through a theorist‘s mind

Visions of hadrons

What is seen by an experimenter