1. Exotic Hadron Spectroscopy at B- factories Toru Iijima Kobayashi-Maskawa Institute Nagoya University KMI Topics Seminar March 11, 2015

2. About Me 1987-1994: 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 d c u c KEK-E176/E224 Hadron spectroscopy is one of my favorite subjects 2 d s uu d s

3. Confirmation of Kobayashi-Maskawa B 0 tag _ March 5, 2014Colloquium at University of Cincinnati3 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 QCD 4 Are 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-quarkPenta-quark Molecule q q q q q meson baryon Ordinal Hadrons 6 quark model c t u d sb up down charm strange top bottom IIIIII q=u, d, s, c, b, t flavor color (R,G,B ） Sakata Model (p, n,  ) Gell-Mann (u,d,s)

5. Gell-Mann 1964 5 Existence of such exotics have long been discussed since the birth of the quark model.

6. Discoveries in 1974 Discovery of J/  SLAC, Burton Richter et al. BNL, Samuel Ting et al. 6 And following qurkonium spectroscopy established physical existence of quarks and qq picture of mesons.

7. Discoveries at B-factories temp 7  c ’ & e + e -  cccc D 0 * 0 & D 1 * 0 X(3872)  c * baryon triplet X(3940), Y(3940)  c2 ’ Y(4660) Y(4008) D sJ (2700)  cx (3090) Z(4430) D sJ (2317/2460) D sJ (2860) Y(4260) Y(4320) Integrated Luminosity Neutral u c u c d c u c u u c c c c g Hybrid cluster Tetraquark Observed >15 Exotic resonances Observed >15 Exotic resonances X(3915), Y(4350) Z(4050),Z(4250) Charged New resonances discovered at B-Factories Zb(10610),Zb(10650) Yb Zb 0 hbhb Z(3885)  b (2S)

8. e + source Ares RF cavity Belle detector SCC RF(HER) ARES(LER) The KEKB Collider e - (8.0GeV) × e + (3.5GeV) ⇒  (4S) →BB ⇒ Lorentz boost:  = 0.425 Finite crossing angle - 11mrad ×2 Operated 1999-2010 Peak luminosity 2.1 x 10 34 cm -2 s -1 ! 2010/10/29 8 Toru Iijima, seminar at Konan

9. Luminosity at B Factories 9 @ Belle

10. Belle Detector Acceptance: 0.9 ×4  Vertex resolution s(J/   ll) ~75nm Momentum resolution  (Pt) = 0.19 ・ Pt  0.34/  % Energy resolution  (E  )/E  =1.8% @ 1GeV Particle ID e, , K, p Minimum bias trigger Evis >= 1GeV & Ntrk >= 2 & Ncluster >= 4 essentially no loss for BB. 10

11. Production of cc in B Factories 11 B factories can produce charmonium (-like) states in four ways.

12. Chamonium-like Exotics 12

13. Discovery of X(3872) 2003, by Belle

14. X (3872) Discovery by Belle in 2003, followed by D0, CDF, BaBar. 14 And more recently also by LHCb, CMS B  K J/  ’’ X(3872) M(D 0 )+M(D *0 )=3871.84 +/- 0.20 PDG2012: M=3871.68 +/- 0.17

15. 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(D 0 ) + M(D *0 ) = 1864.84 + 2006.96 = 3871.80 MeV The width is very narrow D (*) D (*) Molecule Tetraquark “Di-quark” N. A. Tornqvist, PLB590.209 (2004)

16. Belle found Z(4430) + in B  K  +  ’ decays. One-dimensional fit on  ’  + 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 B  K  +  c1 decays. Z(4430) +, Z (4050) +, Z(4250) + by Belle 16 M2(ψ’π+)M2(ψ’π+) PRD80, 031104(2009) Their minimum quark content must be exotic:

17. Z(4430) at LHCb Observation of Z(4430) + – Confirmed the Belle result – J P =1 + LHCB-PAPER-2014-014 17

18. Update of Y(4260)/Y(4008) Updated measurement for e + e - →  +  - J/  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

19. Z(3895) + Dalitz plot of M 2 (  +  - ) and M 2 (  J/  ) for 4.15 < M(  J/  ) < 4.45 GeV/c 2. Similar state also seen by BES III A structure is observed in the M(  J/  ) mass with 5.2  significance. Mass = 3894.5 ± 6.6 ± 4.5 MeV/c 2 Width = 63 ± 24 ± 26 MeV/c 2 A new charged charmonium-like state ! PRL110.252002 (2013) M(  +  - ) [GeV/c 2 ]M(  + J/  ) [GeV/c 2 ] M(  - J/  ) [GeV/c 2 ] PRL110.252001(2013) 19

20. Bottomonium-like Exotics 20

21. Yb: Y(4260) counter part 21 Anomalously large rates  (5S) →  (nS)     ~100 times larger than  (1-4S) →  (nS)     Large rate of Y(4260) → J/      Peak locations are Different ? Hadrons

22. Anomalies in  (5S) decay 22  (3S) h b (2P) h b (1P)  (2S)  (1S)  b (2S)  b (1S)  (4S)  (10860)  (11020) J PC = 0 -+ 1 +- 1 -- 9.50 9.75 10.00 10.25 10.50 10.75 11.00 Mass, GeV/c 2 2M(B) 260 430 290 6 1 2 partial  (keV)  ( 5S )  h b (1,2P)  +  – are not suppressed spin-flip Expect suppression  QCD /m b Heavy Quark Symmetry Violation  [  ( 5S )  (1,2,3S)  +  – ] >>  [  ( 4,3,2S )  (1S)  +  – ] Belle PRL100,112001(2008) h b production Belle PRL108,032001(2012) h b (1P) h b (2P) +–+– 330 190

23. Anomalies in  (5S) decay 23  (3S) h b (2P) h b (1P)  (2S)  (1S)  b (2S)  b (1S)  (4S)  (10860)  (11020) J PC = 0 -+ 1 +- 1 -- 9.50 9.75 10.00 10.25 10.50 10.75 11.00 Mass, GeV/c 2 2M(B) 260 430 290 6 1 2 partial  (keV)  ( 5S )  h b (1,2P)  +  – are not suppressed spin-flip Expect suppression  QCD /m b Heavy Quark Symmetry Violation –– ++ + ZbZb h b production  via intermediate charged states Z b

24. h b (1P, 2P)  +  - 24 Two peaks at the positions same as  (nS)     to look at h b   Fit with h b (1P)  + h b (2P)  +

25. Charged Bottomonium-like Z b + in  (nS)  + 25 Two resonances: Z b + (10510), Z b + (10560)  (1S)  (2S)  (3S) Two peaks at the same positions in the 3 modes.

26. Z b (10610) & Z b (10650) 26 M=10608.4  2.0 MeV  =15.6  2.5 MeV M=10653.2  1.5 MeV  =14.4  3.2 MeV

27. Molecular Explanation of Z b + 27 d b̄b̄ ūū b π B *0 B-B- d b̄b̄ ūū b π B *- Z b + (10510) Z b + (10560) If Z b + 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 h b  is unsuppressed relative to  Relative phase ~0 for  and ~180 0 for h b Production rates of Z b (10610) and Z b (10650) are similar widths

28. Final Remarks 28

29. 29

30. New Resonances by Belle Charm Flavor Region 2003~2009.8(15 states) 2009.8~(11 states) Resonance Spectrum discover by Belle Υ (5S) Υ ( ４ S) Bottom Flavor Region X(3825) Z(3885) +  b (2S) Zb 0 Z(4200) + 30

31. XYZ at B Factories 31 StateMass (MeV)Width (MeV)DecayProduction Ys(2175)2175±858±26 f0f0 ISR X(3872)3871.84±0.33<0.95 J/ , J/  B decay X(3872)3872.8 +0.7/-0.63.9 +2.8/-1.8 D *0 D 0, J/  B decay Y(3915)3915±417±10 J/  Z(3940)3929±529±10DD  X(3940)3942±937±17DD*Double-charm Y(3940)3942±1787±34 J/  B decay Y(4008)4008 +82/-49226 +97/-80 J/  ISR Z(4051) + 4051 +24/-4382 +51/-28  c1 B decay X(4160)4156±29139 +113/-65D*D*Double-charm Z(4248) + 4248 +185/-45177 +320/-72  c1 B decay Y(4260)4264±1283±22 J/  ISR X(4350)4350 +4.7/-5.113 +18/-14 J/  Y(4350)4361±1374±18  ’  ISR Z(4430) + 4433±545 +35/-18 ’’ B decay Y(4660)4664±1248±15  ’  ISR Y b (10890)10889.6±2.354.7 +8.9/-7.6  Υ(nS) e + e - annihilation Z b (10610)10608.4±2.015.6±2.5 (Υ(nS) or h b )  Υ(5S) /Y b decay Z b (10650)10653.2±1.514.4±3.2 (Υ(nS) or h b )  Υ(5S) /Y b decay Tetraquark Hybrid D (*) D (*) Molecule “Di-quark” Light quark charm bottom

32. International Cooperation Super-KEKB J-PARC LEPS2 GSI/FAIR LHC BEPCI I J-LAB JLAB RHIC

33. Charmonium-like Spectroscopy 33 Conventional quark model describes only part of hadronic states. Below DD threshold; –All charmonium states have been observed. –Spectra are in good agreement with naïve quark model However, Above DD threshold; Observed states DO NOT fit to the predicted spectrum. Charged states cannot be Below DD threshold well understood by Above DD threshold ? DD DD*

34. 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 Q q Q q Di-quarkColored meson “New Nagoya Model ?”

35. Hot Region ? 35

36. Impact in the Universe History ? cf. 12 C Hoyle state （ 0 + triple-alpha) William Alfreed Fowler Nobel prize in physics 1983

37. 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 Interpretation Model PredictionVerification Theory Exp.

38. Thank you !

39. X(3872)/Z(4430) at LHCb B + →X(3872)K +, with X(3872)→J/  (  )  +  - J PC = 1 ++ Evidence for the decay X(3872)→y(2S)  Observation of Z(4430) + – Confirmed the Belle result – J P =1 + PRL110, 222001 (2013) LHCB-PAPER-2014-014 LHCB-PAPER-2014-008 39

40. Study of Z b →B*B (*) 40 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 41 M miss (B  ) BB*  B*B*  BB BB* + BB* B*B* significance 9.3  5.7  Full reconstruction of one B in 5 modes BB  M(B) 121.4 fb -1 <0.60 % at 90% C.L. (4.25  0.44  0.69) % (2.12  0.29  0.36) % preliminary BF[  (5S)  B ( * ) B ( * )  ] _ _ _ _ __ _ __ __ Select two peaks recoil mass

42. Observation of Z b  BB* and Z b ’  B*B* 42 M (BB*) M (B*B*) Zb’Zb’ 6.8  phsp ZbZb 88 Z b ’ ? Molecule  admixture of BB* in Z b ’ is small _ Z b ’  BB* is suppressed w.r.t. B*B* despite larger PHSP _ _ _ _ arXiv:1209.6450 Assuming Z b decays are saturated by these channels: preliminary

43. Fit  (2S)  0  0 structure 43 Dalitz plot analysis with Z b swithout o Clear Z b 0 signals are seen in  (2S)π 0 π 0 o Significance of Z b 0 (10610) is 5.3σ (4.9σ with systematics) o Z b 0 (10650) is less significant (~2σ) o Fit gives M(Z b 0 (10610) ) =10609 ± 8 ± 6 MeV cf: M(Z b + )=10607.2 ± 2.0 MeV arXiv:1207.4345

44. H-dibaryon Search 44  (1S, 2S) decays World largest data samples [PRL 110, 222002(2013)] Jaffe, PRL 38, 195 (1977) hypernucleus tri-diquark

45. Doubly-Charmed Hadrons (C=-2) ? Doubly charmed baryons  cc + (ccd),  cc ++ (ccu) have not been established. Evidence reported by SELEX at FNAL, but not confirmed by BaBar/Belle. T cc (udcc, spin=1) predicted to be stable against strong decay (S. H. Lee, S. Yasui); B.E. = M(T cc ) – M(D) – M(D*) = -79MeV.  cs (uudsc), H c (qqqqqc) are also interesting. Good chance also for bottom counterpart. Belle has seen large double charm production. Possible decay modes: 45

46.  cc Search w/ Full Belle Data Y. Kato, T. Iijima et al.,PRD89, 052003 (2014) 46

47. Charmed Strange Bayons  c 47 First observation of  c (3055) 0 ! 980 fb 