Zb states All Results from Belle Jin Li

Zb states (All Results from Belle) Jin Li New Hadron Workshop 2012 -11 -19 1

Anomalies in (5 S) decay (11020) 260 Mass, Ge. V/c 2 2 M(B) 10. 50 + – (4 S) 2 (3 S) 430 10. 25 b(2 S) 330 hb(2 P) 1 (2 S) Belle PRL 108, 032001(2012) 6 (5 S) hb(1, 2 P) + – are not suppressed -- 1 fli (1 S) in - b(1 S) JPC = 0 -+ p partial (ke. V) 9. 50 Meng and Chao PRD 77, 074003(2008) Chen et al. , PRD 84, 074006(2011) 190 hb(1 P) 290 9. 75 + –] 100 >> [ (4, 3, 2 S) (1 S) + –] _ ( Rescattering of on-shell B *)B(*) ? (10860) 10. 75 10. 00 [ (5 S) (1, 2, 3 S) 1+ - sp 11. 00 Belle PRL 100, 112001(2008) expect suppression QCD/mb Heavy Quark Symmetry Violation 2

Anomalies in (5 S) decay (11020) 11. 00 (10860) 260 Mass, Ge. V/c 2 2 M(B) 10. 50 430 10. 25 10. 00 (4 S) 2 (3 S) b(2 S) b + hb(2 P) (2 S) hb(1 P) Belle PRL 108, 032001(2012) 6 (5 S) hb(1, 2 P) + – are not suppressed -- 1 fli (1 S) in - b(1 S) JPC = 0 -+ p partial (ke. V) 9. 50 hb production via intermediate charged states Zb 1 290 9. 75 Z+ – 1+ - sp 10. 75 expect suppression QCD/mb Heavy Quark Symmetry Violation 3

The analysis of hb(n. P)π+π− Studying the decay (5 S) hb(n. P) + -: led to observation of Zb Look at the missing mass of a single pion π−, MM(π−) = M(hb π+). Then fit MM(π +π− ) in bins of MM(π−). Fit Function: Significances with systematic: 1 resonance v. s. 0: 6. 6 σ 2 resonances v. s. 0: 16 σ 4

Resonant structure of (5 S) (bb) + – no non-res. contribution (5 S) hb(2 P) + - _ (5 S) hb(1 P) + - Belle PRL 108, 122001(2012) Two peaks in all modes phsp Minimal quark content _ _ bbud flavor-exotic states M[ hb(1 P) π ] (5 S) (1 S) + - M[ hb(2 P) π ] (5 S) (2 S) + - Dalitz plot analysis (5 S) (3 S) + - note different scales 5

+ Angular analyses for Z b Example : (5 S) Zb+(10610) - [ (2 S) +] - non-resonant cos 1 combinatorial Color coding: JP= 1+ 1 - 2+ 2 - arxiv: 1105. 4583 i ( i, e+), [plane( 1, e+), plane( 1, 2)] , rad cos 2 (0 is forbidden by parity conservation) All angular distributions are consistent with JP=1+ , with other JP disfavored at 3 level. 6

Zb results Zb’ Average over 5 channels M 1 = 10607. 2 2. 0 Me. V 1 = 18. 4 2. 4 Me. V MZb – (MB+MB*) = + 2. 6 2. 1 Me. V M 2 = 10652. 2 1. 5 Me. V 2 = 11. 5 2. 2 Me. V MZb’ – 2 MB* = + 1. 8 1. 7 Me. V Angular analysis both states are JP = 1+ Decays IG = 1+ (C= –) Phase btw Zb and Zb amplitudes is 0 o for (n. S) and 180 o for hb(m. P) ’ 7

Zb amplitudes Properties of Zb amplitudes and phases are consistent with molecular structure. (2 S) = 0 o hb(1 P) yield / 10 Me. V hb = 180 o M(hb ), Ge. V/c 2 Dip due to destructive interference with non-resonant amplitude in the whole Dalitz plane. Information on JP of Zb. 8

Molecule explanation of Zb Wave func. at large distance – B(*)B* Bondar et al, PRD 84, 054010(2011) Proximity to thresholds favors molecule over tetraquark Zb B B* = + B*B* = – S-wave Zb ’ hb(m. P) not suppressed 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. 9

More states can be predicted Sbb 0 1 Sqq States IG(JP) 0 Zb, Zb’ 1+(1+) 1 Wb 0, Wb 0’ 1−(0+) Wb 1 1−(1+) Wb 2 1−(2+) 10

Molecular bottomiums U(? S) Voloshin, PRD 84, 031502 (2011) U(6 S) U(5 S) U b U hb b U b U 0 -(1+) 1+(1+) Wb 0 0+(0+) 1 -(0+) Zb B*B* U U BB* U Xb Wb 1 0+(1+) 1 -(1+) BB Wb 2 0+(2+) 1 -(2+) 11 0 -(1 -) 11 IG(JP)

Other explanations 1. Threshold effect due to initial pion emission B ( *) (5 S) S-wave B ( *) (2 S) _ B ( *) Zb Chen Liu PRD 84, 094003(2011) Zb ’ M [ (2 S)π] Danilkin Orlovsky Simonov PRD 85, 034012(2012) 2. Coupled-channel resonance multiple re-scatterings pole (5 S) B ( *) _ B ( *) + (2 S) B ( *) _ B ( *) (2 S) _ B ( *) +. . . Zb Zb ’ (2 S) 12

Systematic study of B(*) bound states 3. Deuteron-like molecule , , , exchange (5 S) _ B ( *) (2 S) Ohkoda et al PRD 86, 014004 (2012) 13

Study of Zb→B*B(*) _ For the ϒ(5 S) →B*B(*) + channel: • Fully reconstruct one B meson in five exclusive decay modes. • Look at recoil mass of B (for missing B) r. M(B ) and of the pion (for two B combination) r. M( ). _ 14

Clear BB* and B*B* signals _ M(B) _ Full reconstruction of one B in 5 modes recoil mass Mmiss(B ) _ preliminary BF[ (5 S) B(*) ] Belle 121. 4 fb-1 significance _ <0. 60 % at 90% C. L. _ BB _ 9. 3 BB* +_BB* (4. 25 0. 44 0. 69) % B*B* (2. 12 0. 29 0. 36) % 5. 7 Select two peaks _ BB* _ BB _ B*B* PRD 81, 112003(2010) Belle 23. 6 fb-1 (0 1. 2) % (7. 3 2. 3) % (1. 0 1. 4) % 15

Observation of Z BB* and Z ’ B*B* b b _ _ _ M (BB*) Zb 8 Zb ’ ? phsp Zb’ BB* is suppressed w. r. t. B*B* ry despite larger PHSP a n i m i prel ar. Xiv: 1209. 6450 Challenging for tetraquark _ Molecule admixture of BB* in Zb’ is small Assuming Zb decays are saturated by these channels: recoil mass of _ M (B*B*) Zb ’ 6. 8 phsp Crucial input for the models 16

Absolute branching fractions (3 body) Br( (10860)→ (1 S) π+π- )= [4. 45 ± 0. 16(stat. ) ± 0. 35(syst. )] x 10 -3 Br( (10860)→ (2 S) π+π- )= [7. 97 ± 0. 31(stat. ) ± 0. 96(syst. )] x 10 -3 Br( (10860)→ (3 S) π+π- )= [2. 88 ± 0. 19(stat. ) ± 0. 36(syst. )] x 10 -3 Fractions of sub-modes: c. f. PRD 81, 112003(2010) f(BB* )=(7. 3 ± 2. 2 ± 0. 8) % f(B*B* )=(1. 0± 1. 4 ± 0. 4) % Br( (10860)→ BB* ) = [28. 3 ± 2. 9± 4. 6] x 10 -3 Br( (10860)→ B*B*π) = [14. 1 ± 1. 9 ± 2. 4] x 10 -3 17

Study of e+e− (5 S) (n. S) 0 0 preliminary BF[ (5 S) (1 S) 0 0] = (2. 25 0. 11 0. 20) 10 -3 (2 S) BF[ (5 S) (2 S) 0 0] = (3. 79 0. 24 0. 49) 10 -3 in agreement with isospin relations (1 S)π+π- M miss ( 0 0) (n. S)π+π− fit curve (n. S)π0π0 data points (BG subtracted) Is there a neutral Zb partner? (2 S)π+π- 18

Fit (2 S) 0 0 structure ar. Xiv: 1207. 4345 Dalitz plot analysis with Zbs without Y R INA 0 IM L E o Clear Zbs signals are seen in (2 S)π0π0 R P e ell 0 o Significance of Zb(10610) is 5. 3σ (4. 9σ with systematics) 0 o Zb(10650) is less significant (~2σ) o Fit gives M(Zb 0(10610) ) =10609± 8± 6 Me. V B cf: M(Zb+)=10607. 2± 2. 0 Me. V 19

Search for partners of X(3872) Charged partner X+ search J/ψ + 0 channel C-odd neutral partner search J/ψη channel χc 1γ channel ary min i l e r P PRD 84, 052004 (2011) 20

Summary q. Zb+ explanation as molecular states and in (n. S) + and hb(n. P) + decays. q. Observation of Zb+ decays to BB* and B*B* final states in the (5 S) B*B(*) + decay study. q. Zb(10610) decays dominantly to BB*, and Zb(10650) decays dominantly to B*B*. Supporting the molecule explanation. q. Observation of the neutral partner Zb 0(10610) in (5 S) (n. S) 0 0 decay. Mass of Zb 0(10610)= 10609 ± 8 ± 6 Me. V. q. Direct charmonium partner not found. Other recent progress on bottomonium, such as hb(n. P), ηb(n. S), χb(3 P) not covered. 21

BACKUP 22

The bottomonium family (1 S) (2 S) (3 S) (4 S) 2 M(B) Ba. Bar, CLEO collected large ϒ(3 S) data because its rich decay trees. 23

Results of + − missing mass study hb(1 P) (2 S) hb(2 P) (3 S) 2 S 1 S (1 S) 3 S 1 S residuals 121. 4 fb-1 PRL 108 032001 hb(1, 2 P) JPC=1+1 st observations 24

(2) (n. S)ππ production shape Belle, Phys. Rev. , D 82, 091106 R(2010) Rb Energy scan mean of shapes of ( ) and hadronic cross section Rb shapes differ by 2. 0 25

CLEO-c’s e+e− → + − hc cross section An interesting comparison! PRL 107, 041803 (2011) ar. Xiv: 1102. 3424 • (hc + –) (J/ + –) • Γ(Y(4260) → J/ψπ+π−)>508 ke. V@ 90% C. L. Large!! X. H. Mo et al. , Phys. Lett. B 640 (2006) 182 + −hc production is enhanced at Y(4260) + −hb may be enhanced at Yb Substructure of + − hc in Y(4260) has not been studied. Substructure of + − hb : Enough statistics in Belle’s ϒ(5 S) data. Original Motivation for hb search 26

Observation of hb(1 P, 2 P) b(1 S) (5 S) hb(n. P) + – b(1 S) hb(1 P) b(1 S) Fit Mmiss( + -) spectra [ hb yield] in bins of Mmiss( + - ) arxiv: 1205. 6351 MHF(1 S) Belle : 57. 9 2. 3 Me. V 3 PDG’ 12 : 69. 3 2. 8 Me. V Ba. Bar (3 S) Ba. Bar (2 S) hb(2 P) b(1 S) CLEO (3 S) 11. 00 (10860) 10. 75 (4 S) 10. 50 b(3 S) 10. 25 10. 00 p. NRQCD (11020) LQCD b(2 S) + 2 M(B) hb(2 P) hb(1 P) 9. 75 (n) Mmiss ( + - ) Kniehl et al, PRL 92, 242001(2004) Meinel, PRD 82, 114502(2010) Belle result decreases tension with theory +4. 5 Me. V First measurement = 10. 8 +4. 0 – 3. 7 – 2. 0 as expected 9. 50 b(1 S) JPC = 0 -+ (1 S) 1 -- MHF(1 S) 1 -+ (0, 1, 2)++ 27

First evidence for b(2 S) e+e- (5 S) hb(2 P) + – b(2 S) MHF(2 S) = 24. 3 +4. 0– 4. 5 Me. V First measurement arxiv: 1205. 6351 PRL p. NRQCD b(2 S) LQCD Belle 4. 2 w/ syst In agreement with theory (2) Mmiss ( + - ) (2 S) = 4 8 Me. V, < 24 Me. V @ 90% C. L. expect 4 Me. V Branching fractions BF[hb(1 P) b(1 S) ] = 49. 2 5. 7+5. 6 % – 3. 3 +3. 1 BF[hb(2 P) b(1 S) ] = 22. 3 3. 8 % – 3. 3 BF[hb(2 P) b(2 S) ] = 47. 5 10. 5+6. 8 % – 7. 7 c. f. BESIII BF[hc(1 P) c(1 S) ] = 54. 3 8. 5 % Expectations 41% 13% 19% Godfrey Rosner PRD 66, 014012(2002) 39% 28

Observation of Y(5 S)g. Y(1 D) + • pr eli m Y(1 S)[m+m-] + - final state in After b(1 P)g. Y selection ar • y Three peaks in MM( + -): • Y(2 S) + - • Y(1 D) + - • Y(2 S)[Y + -] [ ] reflection statistical significance 9 B[Y(5 S)g. Y(2 S) + -] = (7. 5 1. 1 0. 8) 10 -3 (cross check) B[Y(5 S)g. Y(1 D) + -] B[Y(1 D)g b(1 P) g. Y(1 S) ] = (2. 0 0. 4 0. 3) × 10 -4 P. S. : An evidence of Y(1 D) was seen in inclusive MM( + -) spectra 29

Angular Analysis Zb velocity is very small ( β<0. 02) measure all pion momenta in the c. m. frame. (5 S)→Zb( (n. S), hb+ π1)π2 1= (π1, e+) 2= (π2, e+) = (plane(π1, e+)), plane(π1, π2)) JP = 1 + , 1 − , 2 + , 2 − Non-resonant Example: (5 S)→ Zb(10610) π2 → (2 S)π1 π2 30

Angular Analysis (hb final state) JP = 1 + , 1 − , 2 + , 2 − Example: (5 S)→ Zb(10610) π2 → hb(1 P)π1 π2 Probabilities at which other JP hypotheses are disfavored with respect to 1+ 31