Exotic Hadron Spectroscopy at B-factories

Toru IijimaKobayashi-Maskawa Institute

Nagoya University

KMI Topics SeminarMarch 11, 2015

About Me1987-1994: Kyoto University

H dibaryon search KEK-E176 A-dependence of (K-,K+) BNL-E813/E836

1994-2002: KEK, 2002-now: Nagoya University

B factory Super B factory Particle ID (Cherenkov detectors) CP violation Rare decays Hadron physics

「新ハドロン」新学術領域（ 2009~ ）

KEK-E176

BNL-E813/836

Belle 実験

dc

uc

KEK-E176/E224

Hadron spectroscopy is one of my favorite subjects 2

d s

u u

d s

Confirmation of Kobayashi-Maskawa

B0 tag_B

0 tag

March 5, 2014 Colloquium at University of Cincinnati 3

Press release from the Academy

“As late as 2001, the two particle detectors BaBar at Stanford, USA and Belle at Tsukuba, Japan, both detected broken symmetries independently of each other. The results were exactly as Kobayashi and Maskawa had predicted almost three decades earlier. “

4

Quest in low-energy QCDAre there exotics beyond meson(qq) /baryon (qqq) ?

QCD just require hadrons to be colorless, and allow exotics.

Such exotic states exist ?

New Hadrons （ Exotics ）Tetra-quark Penta-quark Molecule

q q

qq q

meson baryonOrdinal Hadrons

6 quark modelc tu

d s b

up

down

charm

strange

top

bottom

I II IIIq=u, d, s, c, b, t

flavor

color (R,G,B ）

Sakata Model(p, n, L)

Gell-Mann(u,d,s)

Gell-Mann 1964

5

Existence of such exotics have long been discussed since the birth of the quark model.

Discoveries in 1974 Discovery of J/y

SLAC, Burton Richter et al. BNL, Samuel Ting et al.

6

c c

And following qurkonium spectroscopy established physical existence of quarks and qq picture of mesons.

Discoveries at B-factories

• temp

7

hc’ & e+e-ccccD0*0 & D1*0

X(3872)

Sc* baryon triplet

X(3940), Y(3940)

cc2’

Y(4660) Y(4008)

DsJ(2700)Xcx(3090)

Z(4430)

DsJ(2317/2460)

DsJ(2860)

Y(4260)

Y(4320)

Integ

rated L

um

inosity Neutral

uc

uc

dc

uc

u u

c c

cc

g

Hybrid

clusterTetraquark

Observed >15 Exotic resonances

X(3915), Y(4350)Z(4050),Z(4250)

Charged

New resonances discovered at B-Factories Zb(10610),Zb(10650)

Yb

Zb0

hb

Z(3885)

hb(2S)

e+ source

Ares RF cavity

Belle detectorSCC RF(HER)

ARES(LER)

The KEKB Collider e- (8.0GeV) × e+ (3.5GeV)

⇒U(4S) →BB⇒Lorentz boost:

bg = 0.425 Finite crossing angle

- 11mrad ×2 Operated 1999-2010

Peak luminosity

2.1 x 1034 cm-2s-1 !

2010/10/29 8Toru Iijima, seminar at Konan

9

Luminosity at B Factories

@ Belle

Belle Detector Acceptance: 0.9 ×4p Vertex resolution

s(J/y ll) ~75nm Momentum resolution

s(Pt) = 0.19 ・ Pt 0.34/b %

Energy resolution

s(Eg)/Eg =1.8% @ 1GeV Particle ID

e, , m p, K, p Minimum bias trigger

Evis >= 1GeV & Ntrk >= 2

& Ncluster >= 4

essentially no loss for BB.

10

Production of cc in B Factories

11

B factories can produce charmonium (-like) states in four ways.

Chamonium-like Exotics

12

Discovery of X(3872)2003, by Belle

X (3872)Discovery by Belle in 2003, followed by D0, CDF, BaBar.

14

And more recently also by LHCb, CMS

BK J/ypp

’y

X(3872)

M(D0)+M(D*0)=3871.84 +/- 0.20PDG2012: M=3871.68 +/- 0.17

What is X(3872) ?• PDG2014

– mass 　 M ＝ 3871.69 ± 0.17 MeV– Width Γ < 1.2 MeV (90%C.L.)

• The observed mass is – different from that predicted by conventional charmonium

picture.– Very close to M(D0) + M(D*0) = 1864.84 + 2006.96 =

3871.80 MeV

• The width is very narrow

c

u

cu

πc

u

c

uu

cuccu

π

D(*)D(*) Molecule

cuc ucuu

cc u

Tetraquark

“Di-quark”

N. A. Tornqvist, PLB590.209 (2004)

Belle found Z(4430)+ in BK p+ y’ decays. One-dimensional fit on y’p+ distribution after

K*(890) /K*(1430) vetos.

Confirmed by analysis with a full Dalitz plot.

Belle found also another two states, Z(4050)+ & Z(4250)+, in BK p+ cc1 decays.

Z(4430)+, Z (4050)+, Z(4250)+ by Belle

16

M2(ψ’π+)

PRD80, 031104(2009)

PRD80, 031104(2009)

Their minimum quark content must be exotic:

Z(4430) at LHCb

• Observation of Z(4430)+

– Confirmed the Belle result

– JP=1+

LHCB-PAPER-2014-014

17

Update of Y(4260)/Y(4008) Updated measurement for e+e- → p+p-J/y w/ initial state

radiation (ISR) using full Belle data sample (967fb-1).

Two resonances; Y(4008) and Y(4260) are observed, consistent with the previous Belle measurement.

Resonance parameters

PRL110.252002(2013)18

Z(3895)+

Dalitz plot of M2(p+p-) and M2(pJ/y) for 4.15 < M(ppJ/y) < 4.45 GeV/c2.

Similar state also seen by BES III

A structure is observed in the M(pJ/y) mass with 5.2 s significance. • Mass = 3894.5 ± 6.6 ± 4.5 MeV/c2

• Width = 63 ± 24 ± 26 MeV/c2

A new charged charmonium-like state !

PRL110.252002 (2013)

M(p+p-) [GeV/c2] M(p+ J/y) [GeV/c2] M(p- J/y) [GeV/c2]

PRL110.252001(2013)

19

Bottomonium-like Exotics

20

Yb: Y(4260) counter part

21

Anomalously large rates(5S) → (nS) p+p- ~100 times larger than(1-4S) → (nS) p+p-

Large rate ofY(4260) → J/y p+p-

Peak locations areDifferent ?

Hadrons

22

Anomalies in (5S) decay

(3S)hb(2P)

hb(1P)

(2S)

(1S)

b(2S)

b(1S)

(4S)

(10860)

(11020)

JPC = 0 -+1+-1 --

9.50

9.75

10.00

10.25

10.50

10.75

11.00

Mass

, G

eV

/c2 2M(B)

260

430

290 6

1

2

partial (keV) (5S) hb(1,2P) +– are not suppressed

spin-

flipExpect suppression QCD/mb

Heavy Quark Symmetry Violation

[(5S) (1,2,3S) +–] >> [(4,3,2S)

(1S) +–] Belle PRL100,112001(2008)

hb production

Belle PRL108,032001(2012)

hb(1P)hb(2P)

+–

330

190

23

Anomalies in (5S) decay

(3S)hb(2P)

hb(1P)

(2S)

(1S)

b(2S)

b(1S)

(4S)

(10860)

(11020)

JPC = 0 -+1+-1 --

9.50

9.75

10.00

10.25

10.50

10.75

11.00

Mass

, G

eV

/c2 2M(B)

260

430

290 6

1

2

partial (keV) (5S) hb(1,2P) +– are not suppressed

spin-

flipExpect suppression QCD/mb

Heavy Quark Symmetry Violation

–

+

+Zb hb production via intermediate charged states Zb

hb (1P, 2P) p+ p-

24

Two peaks at the positions same as (nS)p+p-

to look at hb p+

Fit with

hb(1P) p+ hb(2P) p+

Charged Bottomonium-like Zb+ in (nS)p+

25

Two resonances: Zb+(10510), Zb

+(10560)

(1S) (2S) (3S)

Two peaks at the same positions in the 3 modes.

Zb(10610) & Zb(10650)

26

M=10608.42.0 MeV

=15.62.5 MeVM=10653.21.5 MeV

=14.43.2 MeV

Molecular Explanation of Zb+

27

d

bA

u

b π

B*

0

B-

d

bA

u

b π

B*

0

B*-

Zb+(10510) Zb

+(10560)

If Zb+ is B*B(*) molecule, it should decay into B*B(*)…

Bondar et al, PRD84,054010(2011)

Proximity to thresholds favors molecule picture

Each of them is mixture of spin triplet and singlet bb

This model explains

• Why hb is unsuppressed relative to

• Relative phase ~0 for and ~1800 for hb

• Production rates of Zb(10610) and Zb(10650) are similar widths

Final Remarks

28

29

New Resonances by Belle

Charm Flavor Region

2003~2009.8(15 states)2009.8~(11 states)

Resonance Spectrum discover by BelleΥ(5S)

Υ( ４ S)

Bottom Flavor Region

X(3

825)

Z(3

885)

+

hb(

2S) Z

b0

Z(4

200)

+

30

XYZ at B Factories

31

State Mass (MeV) Width (MeV) Decay Production

Ys(2175) 2175±8 58±26 ff0 ISR

X(3872) 3871.84±0.33 <0.95 J/ypp, J/yg B decay

X(3872) 3872.8 +0.7/-0.6 3.9 +2.8/-1.8 D*0D0, J/yw B decay

Y(3915) 3915±4 17±10 J/yw gg

Z(3940) 3929±5 29±10 DD gg

X(3940) 3942±9 37±17 DD* Double-charm

Y(3940) 3942±17 87±34 J/yw B decay

Y(4008) 4008 +82/-49 226 +97/-80 J/ypp ISR

Z(4051)+ 4051 +24/-43 82 +51/-28 pcc1 B decay

X(4160) 4156±29 139 +113/-65 D*D* Double-charm

Z(4248)+ 4248 +185/-45 177 +320/-72 pcc1 B decay

Y(4260) 4264±12 83±22 J/ypp ISR

X(4350) 4350 +4.7/-5.1 13 +18/-14 J/yf gg

Y(4350) 4361±13 74±18 y’pp ISR

Z(4430)+ 4433±5 45 +35/-18 y’p B decay

Y(4660) 4664±12 48±15 y’pp ISR

Yb(10890) 10889.6±2.3 54.7 +8.9/-7.6 ppΥ(nS) e+e- annihilation

Zb(10610) 10608.4±2.0 15.6±2.5 (Υ(nS) or hb) p Υ(5S) /Yb decay

Zb(10650) 10653.2±1.5 14.4±3.2 (Υ(nS) or hb) p Υ(5S) /Yb decay

c

u

cu

πc

u

c

uu

cuccu

π

cuc ucuu

cc u

cc

gccc

g

Tetraquark

Hybrid

D(*)D(*) Molecule

“Di-quark”Light

quark

charm

bottom

International CooperationSuper-KEKB J-PARCLEPS2

GSI/FAIR

LHC BEPCII

J-LAB

JLAB

RHIC

Charmonium-like Spectroscopy

33Conventional quark model describes only part of hadronic states.

4

3S

QCDV krr

Below DD thresholdwell understood by

Above DD threshold

?DD

DD*

New Quark Model ? Conventional quark model does

not work for excited states.D.O.F. = “constituent quark”

Can we build a new (extended) quark model ?D.O.F. = quasi-particle ?

34

Qq

Qq

Di-quark Colored meson

“New Nagoya Model ?”

Hot Region ?

35

Impact in the Universe History ?

cf. 12C Hoyle state （ 0+ triple-alpha) William Alfreed Fowler Nobel prize in physics 1983

Summary Exotic hadron spectroscopy is very hot topics.

Experimentally, it has been and will be very productive.

The real value is unknown (honestly speaking), although I “believe” it is significant.

KMI is a good place to discuss Collaboration between exp. – theory is essential. Link to the universe development ???

New data InterpretationModel

PredictionVerification

TheoryExp.

Thank you !

X(3872)/Z(4430) at LHCb• B+ →X(3872)K+, with X(3872)→J/y(mm)p+p- JPC = 1++

• Evidence for the decay X(3872)→y(2S) g

• Observation of Z(4430)+

– Confirmed the Belle result

– JP=1+

PRL110, 222001 (2013)

LHCB-PAPER-2014-014

LHCB-PAPER-2014-008

39

40

Study of Zb→B*B(*)

For the ϒ(5S) →B*B(*) + channel:Fully reconstruct one B meson in five exclusive decay

modes.

Look at recoil mass of B (for missing B) rM(B)

and of the pion (for two B combination) rM().

_

41

Clear BB* and B*B* signals

Mmiss(B)BB*

B*B*

BB BB* + BB*

B*B*

significance

9.35.7

Full reconstruction of one B in 5 modes

BBM(B)

121.4 fb-1

<0.60 % at 90% C.L.(4.25 0.44 0.69) %(2.12 0.29 0.36) %

preliminaryBF[ (5S) B(*)B(*) ]

_

_

_

_

___

__

_ _

Select two peaks

recoil mass

42

Observation of ZbBB* and Zb’B*B*M (BB*)

M (B*B*)

Zb’

6.8

phsp

Zb

8

phsp

Zb’ ? Molecule admixture of BB* in Zb’ is small

_

Zb’ BB* is suppressed w.r.t. B*B*despite larger PHSP

_ __

_

arXiv:1209.6450

Assuming Zb decays are saturated by these channels:preliminary

43

Fit (2S)00 structureDalitz plot analysis

with Zbs without

o Clear Zb0 signals are seen in (2S)π0π0

o Significance of Zb0(10610) is 5.3σ (4.9σ with systematics)

o Zb0(10650) is less significant (~2σ)

o Fit gives M(Zb0(10610) ) =10609±8±6 MeV

cf: M(Zb+)=10607.2±2.0 MeV

arXiv:1207.4345

H-dibaryon Search

44

(1S, 2S) decays World largest data samples

[PRL 110, 222002(2013)]

Jaffe, PRL 38, 195 (1977)

hypernucleus

tri-diquark

Doubly-Charmed Hadrons (C=-2) ? Doubly charmed baryons Xcc

+(ccd), Xcc++(ccu) have not been

established. Evidence reported by SELEX at FNAL, but not confirmed by

BaBar/Belle.

Tcc (udcc, spin=1) predicted to be stable against strong decay (S. H. Lee, S. Yasui); B.E. = M(Tcc) – M(D) – M(D*) = -79MeV.

Qcs(uudsc), Hc (qqqqqc) are also interesting.

Good chance also for bottom counterpart.

Belle has seen large double charm production.

Possible decay modes:

45

Xcc Search w/ Full Belle DataY. Kato, T. Iijima et al.,PRD89, 052003 (2014)

46

Charmed Strange Bayons Xc

47

First observation of Xc(3055)0 !

980 fb-1