Exotic Hadron Spectroscopy at Bfactories Toru Iijima KobayashiMaskawa
Exotic Hadron Spectroscopy at Bfactories Toru Iijima Kobayashi-Maskawa Institute Nagoya University KMI Topics Seminar March 11, 2015
About Me KEK-E 176/E 224 BNL-E 813/836 1987 -1994: Kyoto University n H dibaryon search n KEK-E 176 n A-dependence of (K-, K+) n BNL-E 813/E 836 u d s s 1994 -2002: KEK, 2002 -now: Nagoya University n B factory Super B factory n Particle ID (Cherenkov detectors) n CP violation n Rare decays n Hadron physics n 「新ハドロン」新学術領域(2009~) Belle実験 Hadron spectroscopy is one of my favorite subjects u c c d 2
Confirmation of Kobayashi-Maskawa 0 tag B _ B 0 tag Press release from the Academy “As late as 2001, the two particle detectors Ba. Bar 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. “ March 5, 2014 Colloquium at University of Cincinnati 3
Quest in low-energy QCD Are there exotics beyond meson(qq) /baryon (qqq) ? Sakata Model (p, n, ) 6 quark model I II III u c t up Gell-Mann (u, d, s) q q s d down Ordinal Hadrons meson charm baryon top b strange q=u, d, s, c, b, t flavor color (R, G, B) bottom New Hadrons(Exotics) Tetra-quark Penta-quark Molecule q q q QCD just require hadrons to be colorless, and allow exotics. Such exotic states exist ? 4
Gell-Mann 1964 Existence of such exotics have long been discussed since the birth of the quark model. 5
Discoveries in 1974 n Discovery of J/y n SLAC, Burton Richter et al. n BNL, Samuel Ting et al. And following qurkonium spectroscopy established physical existence of quarks and qq picture of mesons. 6
Discoveries at B-factories New resonances discovered Zb 0 at B-Factories Zb(10610), Zb(10650) Integrated Luminosity • temp X(3915), Y(4350) Yb Z(4050), Z(4250) Y(4660) Z(4430) Y(4008) Ds. J(2700) Xcx(3090) cc 2’ X(3940), Y(3940) Sc* baryon triplet X(3872) D 0*0 & D 1*0 Ds. J(2860) Y(4320) Y(4260) Ds. J(2317/2460) hc’ & e+e- cccc hb Observed >15 Exotic resonances Z(3885) hb(2 S) Charged u c c Tetraquark Neutral u u u d c c cluster g c c u Hybrid 7
The KEKB Collider SCC RF(HER) ARES(LER) - (8. 0 Ge. V) × e+ (3. 5 Ge. V) n e Belle detector ⇒U(4 S) →BB ⇒Lorentz boost: bg = 0. 425 n Finite crossing angle - 11 mrad × 2 n Operated 1999 -2010 Ares RF cavity e+ source 2010/10/29 Toru Iijima, seminar at Konan Peak luminosity 2. 1 x 1034 cm-2 s-1 ! 8
Luminosity at B Factories @ Belle 9
Belle Detector n Acceptance: 0. 9 × 4 n Vertex resolution s(J/y ll) ~75 nm n Momentum resolution (Pt) = 0. 19・Pt 0. 34/b % n Energy resolution (Eg)/Eg =1. 8% @ 1 Ge. V n Particle ID e, m, , K, p n Minimum bias trigger Evis >= 1 Ge. V & Ntrk >= 2 & Ncluster >= 4 essentially no loss for BB. 10
Production of cc in B Factories B factories can produce charmonium (-like) states in four ways. 11
Chamonium-like Exotics 12
Discovery of X(3872) 2003, by Belle
X (3872) Discovery by Belle in 2003, followed by D 0, CDF, Ba. Bar. y’ B K J/y X(3872) And more recently also by LHCb, CMS PDG 2012: M=3871. 68 +/- 0. 17 14 M(D 0)+M(D*0)=3871. 84 +/- 0. 20
What is X(3872) ? • PDG 2014 – mass M= 3871. 69 ± 0. 17 Me. V – Width Γ < 1. 2 Me. V (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 Me. V • The width is very narrow N. A. Tornqvist, PLB 590. 209 (2004) Tetraquark “Di-quark” D(*) Molecule
Z(4430)+, Z (4050)+, Z(4250)+ by Belle n Belle found Z(4430)+ in B K + y’ decays. n One-dimensional fit on y’ + distribution after K*(890) /K*(1430) vetos. PRD 80, 031104(2009) n Confirmed by analysis with a full Dalitz plot. PRD 80, 031104(2009) n Belle found also another two states, Z(4050)+ & M 2(ψ’π+) Z(4250)+, in B K + cc 1 decays. Their minimum quark content must be exotic: 16
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) n Updated measurement for e+e- → + -J/y w/ initial state radiation (ISR) using full Belle data sample (967 fb-1). n Two resonances; Y(4008) and Y(4260) are observed, consistent with the previous Belle measurement. Resonance parameters 18 PRL 110. 252002(2013)
PRL 110. 252002 (2013) Z(3895)+ n Dalitz plot of M 2( + -) and M 2( J/y) for 4. 15 < M( J/y) < 4. 45 Ge. V/c 2. M( + -) [Ge. V/c 2] M( + J/y) [Ge. V/c 2] M( - J/y) [Ge. V/c 2] n A structure is observed in the M( J/y) mass with 5. 2 significance. • Mass = 3894. 5 ± 6. 6 ± 4. 5 Me. V/c 2 • Width = 63 ± 24 ± 26 Me. V/c 2 n Similar state also seen by BES III PRL 110. 252001(2013) A new charged charmonium-like state ! 19
Bottomonium-like Exotics 20
Yb: Y(4260) counter part Hadrons Large rate of Y(4260) → J/y + Anomalously large rates (5 S) → (n. S) + ~100 times larger than (1 -4 S) → (n. S) + Peak locations are Different ? 21
Anomalies in (5 S) decay (11020) 11. 00 10. 75 (10860) (4 S) 2 (3 S) Mass, Ge. V/c 2 10. 50 10. 00 + – 260 2 M(B) 10. 25 [ (5 S) (1, 2, 3 S) + –] >> [ (4, 3, 2 S) (1 S) + –] 430 b(2 S) hb(1 P) 190 hb(1 P) 6 Belle PRL 108, 032001(2012) (5 S) hb(1, 2 P) + – are not suppressed in - fli p (1 S) sp b(1 S) hb(2 P) partial (ke. V) 9. 50 hb production 330 1 290 9. 75 Belle PRL 100, 112001(2008) JPC = 0 -+ 1 -- 1+- Expect suppression QCD/mb Heavy Quark Symmetry Violation 22
Anomalies in (5 S) decay (11020) 11. 00 10. 75 (10860) 260 (4 S) 2 (3 S) Mass, Ge. V/c 2 2 M(B) 10. 50 10. 25 10. 00 – 430 b(2 S) + hb(2 P) (2 S) hb(1 P) 6 (5 S) hb(1, 2 P) + – are not suppressed partial (ke. V) fli p (1 S) in - b(1 S) sp 9. 50 hb production via intermediate charged states Zb 1 290 9. 75 Zb+ JPC = 0 -+ 1 -- 1+- Expect suppression QCD/mb Heavy Quark Symmetry Violation 23
hb (1 P, 2 P) + hb(1 P) + hb(2 P) + to look at hb + Fit with Two peaks at the positions same as (n. S) + 24
Charged Bottomonium-like Zb+ in (n. S) + Two peaks at the same positions in the 3 modes. (1 S) (2 S) (3 S) Two resonances: Zb+(10510), Zb+(10560) 25
Zb(10610) & Zb(10650) M=10608. 4 2. 0 Me. V M=10653. 2 1. 5 Me. V =15. 6 2. 5 Me. V =14. 4 3. 2 Me. V 26
Molecular Explanation of Zb+ Bondar et al, PRD 84, 054010(2011) Proximity to thresholds favors molecule picture Zb+(10510) b u B- π b d B*0 Zb+(10560) b u B*- π Each of them is mixture of spin triplet and singlet bb b d B*0 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 If Zb+ is B*B(*) molecule, it should decay into B*B(*)… 27
Final Remarks 28
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New Resonances by Belle Resonance Spectrum discover by Belle Υ(4 S) Υ(5 S) 2003~2009. 8(15 states) 2009. 8~(11 states) Zb 0 Bottom Flavor Region b(2 S) Z(4200)+ X(3825) Z(3885)+ Charm Flavor Region 30
XYZ at B Factories t h g Li ark qu r ha m c bo m tto State Mass (Me. V) Width (Me. V) Decay Production Ys(2175) 2175± 8 58± 26 ff 0 ISR X(3872) 3871. 84± 0. 33 <0. 95 J/y , J/yg B decay X(3872) 3872. 8 +0. 7/-0. 6 3. 9 +2. 8/-1. 8 D*0 D 0, 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/y ISR Z(4051)+ 4051 +24/-43 82 +51/-28 cc 1 B decay X(4160) 4156± 29 139 +113/-65 D*D* Double-charm Z(4248)+ 4248 +185/-45 177 +320/-72 cc 1 B decay Y(4260) 4264± 12 83± 22 J/y ISR X(4350) 4350 +4. 7/-5. 1 13 +18/-14 J/yf gg Y(4350) 4361± 13 74± 18 y’ ISR Z(4430)+ 4433± 5 45 +35/-18 y’ B decay Y(4660) 4664± 12 48± 15 y’ ISR Yb(10890) 10889. 6± 2. 3 54. 7 +8. 9/-7. 6 Υ(n. S) e+e- annihilation Zb(10610) 10608. 4± 2. 0 15. 6± 2. 5 (Υ(n. S) or hb) Υ(5 S) /Yb decay Zb(10650) 10653. 2± 1. 5 14. 4± 3. 2 (Υ(n. S) or hb) Υ(5 S) /Yb decay Tetraquark “Di-quark” D(*) Molecule Hybrid 31
International Cooperation LEPS 2 Super-KEKB GSI/FAIR J-PARC JLAB LHC BEPCII RHIC J-LAB
Charmonium-like Spectroscopy Above DD threshold DD* DD ? Below DD threshold well understood by Conventional quark model describes only part of hadronic states. 33
New Quark Model ? n Conventional quark model does not work for excited states. D. O. F. = “constituent quark” n Can we build a new (extended) quark model ? D. O. F. = quasi-particle ? Q q Di-quark Q q Colored meson “New Nagoya Model ? ” 34
Hot Region ? 35
Impact in the Universe History ? cf. 12 C Hoyle state(0+ triple-alpha) William Alfreed Fowler Nobel prize in physics 1983
Summary n Exotic hadron spectroscopy is very hot topics. n Experimentally, it has been and will be very productive. n The real value is unknown (honestly speaking), although I “believe” it is significant. n KMI is a good place to discuss n Collaboration between exp. – theory is essential. n Link to the universe development ? ? ? New data Exp. Verification Interpretation Model Prediction Theory
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(2 S) g PRL 110, 222001 (2013) LHCB-PAPER-2014 -008 • Observation of Z(4430)+ – Confirmed the Belle result – JP=1+ LHCB-PAPER-2014 -014 39
Study of Zb (*) →B*B For the ϒ(5 S) →B*B(*) + channel: _ n Fully reconstruct one B meson in five exclusive decay modes. n Look at recoil mass of B (for missing B) r. M(B ) and of the pion (for two B combination) r. M( ). 40
_ _ Clear BB* and B*B* signals Full reconstruction of one B in 5 modes Mmiss(B ) recoil mass M(B) Select two peaks _ BB* _ BB _ B*B* preliminary BF[ (5 S) B(*) ] 121. 4 fb-1 _ <0. 60 % at 90% C. L. _ BB* +_BB* (4. 25 0. 44 0. 69) % B*B* (2. 12 0. 29 0. 36) % significance 9. 3 5. 7 41
Observation of Zb BB* and Zb’ B*B* Zb _ M (BB*) 8 Zb ’ ? phsp y r a n mi preli _ Zb’ BB* is suppressed w. r. t. B*B* despite larger PHSP _ _ in Zb’ Molecule admixture of BB* is small Assuming Zb decays are saturated by these channels: _ M (B*B*) Zb ’ 6. 8 phsp ar. Xiv: 1209. 6450 42
Fit (2 S) 0 0 structure ar. Xiv: 1207. 4345 Dalitz plot analysis with Zbs o o without Clear Zb 0 signals are seen in (2 S)π0π0 Significance of Zb 0(10610) is 5. 3σ (4. 9σ with systematics) Zb 0(10650) is less significant (~2σ) Fit gives M(Zb 0(10610) ) =10609± 8± 6 Me. V cf: M(Zb +)=10607. 2± 2. 0 Me. V 43
H-dibaryon Search (1 S, 2 S) decays World largest data samples tri-diquark Jaffe, PRL 38, 195 (1977) hypernucleus [PRL 110, 222002(2013)] 44
Doubly-Charmed Hadrons (C=-2) ? n Doubly charmed baryons Xcc+(ccd), Xcc++(ccu) have not been established. n Evidence reported by SELEX at FNAL, but not confirmed by Ba. Bar/Belle. n Tcc (udcc, spin=1) predicted to be stable against strong decay (S. H. Lee, S. Yasui); n B. E. = M(Tcc) – M(D*) = -79 Me. V. Possible decay modes: n Qcs(uudsc), Hc (qqqqqc) are also interesting. n Good chance also for bottom counterpart. n Belle has seen large double charm production. 4 5
Y. Kato, T. Iijima et al. , PRD 89, 052003 (2014) Xcc Search w/ Full Belle Data 46
Charmed Strange Bayons Xc First observation of Xc(3055)0 ! 980 fb-1 47
- Slides: 47