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Bottomonium and bottomonium –like states

Bottomonium and bottomonium –like states. Alex Bondar On behalf of Belle Collaboration. Cracow Epiphany Conference “Present and Future B-physics” (9 - 11, January, 2012, Cracow, Poland ). Observation of Z b. . Outline.  (1S)  +  -  (2S)  +  -  (3S)  +  -

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Bottomonium and bottomonium –like states

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  1. Bottomonium and bottomonium–like states Alex Bondar On behalf of Belle Collaboration Cracow Epiphany Conference “Present and Future B-physics”(9 - 11, January, 2012, Cracow, Poland )

  2. Observation of Zb  Outline (1S)+- (2S)+- (3S)+- hb(1P)+- b(1S) +- hb(2P)+- Zb(10610)+- Zb(10650)+- (5S) at BB* and B*B* thresholds  molecules Observation of hb(1P) and hb(2P) arXiv:1103.3419 accepted by PRL arXiv:1110.2251 final state w/ hb(nP) and(nS) accepted by PRL angular analysis arXiv:1105.4583 Observation of hb(1P) b(1S) arXiv:1110.3934

  3. Anomalous production of (nS)+- PRD82,091106R(2010) (MeV) PRL100,112001(2008) line shape of Yb 102 (5S) Simonov JETP Lett 87,147(2008) 1. Rescattering (5S)BB(nS)? 2.Similar effect in charmonium? Y(4260) with anomalous (J/+-)  assume  Yb close to (5S) to distinguish energy scan  shapes of Rb and () different (2)

  4. Observation of hb(1P) & hb(2P)

  5. Trigger CLEO observed e+e- → hc+– @ ECM=4170MeV (hc+–) (J/+–) PRL107, 041803 (2011) Y(4260) Hint of rise in (hc+-) @ Y(4260) ? 4260 Y(4260)Yb search for hb(nP)+- @ (5S)

  6. Introduction to hb(nP) MM(+-) _ (bb) : S=0 L=1 JPC=1+- Expected mass  (Mb0 + 3 Mb1 + 5 Mb2) / 9 MHF test of hyperfine interaction For hcMHF= 0.00  0.15 MeV, expect smaller deviation for hb(nP) Previous search arXiv:1102.4565 PRD 84, 091101 BaBar 3.0 (3S) → 0 hb(1P)

  7. Introduction to hb(nP) MM(+-) _ (bb) : S=0 L=1 JPC=1+- Expected mass  (Mb0 + 3 Mb1 + 5 Mb2) / 9 MHF test of hyperfine interaction For hcMHF= 0.00  0.15 MeV, expect smaller deviation for hb(nP) Previous search arXiv:1102.4565 PRD 84, 091101 BaBar 3.0 (3S) → 0 hb(1P)

  8. (5S)  hb +- reconstruction reconstructed * * M(hb) =  Mmiss(+-) (Ec.m. – E+-)2 – p+- 2 hb → ggg, b (→ gg)  no good exclusive final states “Missing mass” (1S) hb(1P) (2S) hb(2P) (3S)

  9. Results 121.4 fb-1 Significance w/ systematics hb(1P) 5.5 hb(2P) 11.2

  10. Hyperfine splitting Deviations from CoG (Center of Gravity) of bJmasses hb(1P)(1.7  1.5) MeV/c2 hb(2P)(0.5 +1.6 ) MeV/c2 consistent with zero, as expected -1.2 Ratio of production rates spin-flip for hb(1P) = for hb(2P) no spin-flip Process with spin-flip of heavy quark is not suppressed • Mechanism of (5S)  hb(nP) +- decay violates • Heavy Quark Spin Symmetry

  11. Resonant structure of (5S)hb(nP) +-

  12. Resonant structure of (5S)  hb(1P)+- phase-space MC M(hb–), GeV/c2 M(hb+), GeV/c2

  13. Resonant structure of (5S)  hb(1P)+- Fit function _ ~BB* threshold M1 = MeV/c2 _ _ 1 = MeV a = ~B*B* threshold M2 = MeV/c2 2 = MeV  = degrees 121.4 fb-1 phase-space MC fit Mmiss(+–)in M(hb) bins  M(hb–), GeV/c2 hb(1P) yield / 10MeV M(hb+), GeV/c2 Zb(10610), Zb(10650) M(hb), GeV/c2 Results Significance 18 (16 w/ syst) non-res.~0

  14. Resonant structure of (5S)  hb(2P)+- M1 = MeV/c2 1 = MeV a = M2 = MeV/c2 2 = MeV  = degrees 121.4 fb-1 phase-space MC fit Mmiss(+–)in M(hb) bins  M(hb–), GeV/c2 hb(1P) yield / 10MeV M(hb+), GeV/c2 M(hb), GeV/c2 hb(1P)+- hb(2P)+- MeV/c2 MeV MeV/c2 c o n s i s t e n t Significances MeV 6.7 (5.6 w/ syst) degrees non-res.~0 non-res. set to zero 14

  15. Resonant structure of (5S)(nS) +- (n=1,2,3)

  16. (5S) (nS)+- (n = 1,2,3)  +- (3S) (2S) (1S) reflections Mmiss (+-), GeV/c2

  17. (5S) (nS)+- (n = 1,2,3)  +- purity 92 – 94% (3S) (2S) (1S) Mmiss (+-), GeV/c2

  18. (5S) (nS) +- Dalitz plots (1S) (2S) (3S)

  19. (5S) (nS) +- Dalitz plots (1S) (2S) (3S) Signals ofZb(10610) and Zb(10650)

  20. Fitting the Dalitz plots Angular analysis favors JP=1+ S-wave S-wave (5S)  Zb, Zb(nS) – no spin orientation change Non-resonant heavy quark spin-flip amplitude is suppressed Spins of (5S) and (nS) can be ignored Signal amplitude parameterization: S(s1,s2) = A(Zb1) + A(Zb2) + A(f0(980)) + A(f2(1275)) + ANR ANR = C1 + C2∙m2(ππ) Parameterization of the non-resonant amplitude is discussed in [1] M.B. Voloshin, Prog. Part. Nucl. Phys. 61:455, 2008. [2] M.B. Voloshin, Phys. Rev. D74:054022, 2006. A(Zb1) + A(Zb2) + A(f2(1275)) – Breit-Wigner A(f0(980)) – Flatte

  21. Results: (1S)π+π- signals M((1S)π+), GeV M((1S)π-), GeV reflections 21

  22. Results: (2S)π+π- signals reflections M((2S)π-), GeV M((2S)π+), GeV

  23. Results: (3S)π+π- M((3S)π+), GeV M((3S)π-), GeV

  24. Summary of Zb parameters Average over 5 channels  M1 = 10607.22.0 MeV  1  = 18.42.4 MeV  M2 = 10652.21.5 MeV  2  = 11.5  2.2 MeV

  25. Summary of Zb parameters hb(1P) yield / 10MeV M(hb), GeV/c2 Average over 5 channels  M1 = 10607.22.0 MeV  1  = 18.42.4 MeV  = 180o  = 0o  M2 = 10652.21.5 MeV  2  = 11.5  2.2 MeV Zb(10610) yield ~ Zb(10650) yield in every channel Relative phases: 0o for  and 180o for hb

  26. Angular analysis

  27. Angular analysis Definition of angles i(i,e+),[plane(1,e+), plane(1, 2)] Example : (5S)  Zb+(10610) -  [(2S)+] - cos1 cos2 , rad combinatorial non-resonant Color coding: JP=1+ 1- 2+ 2- (0 is forbidden by parity conservation) Best discrimination: cos2 for 1-(3.6) and 2-(2.7); cos1 for2+(4.3)

  28. Summary of angular analysis All angular distributions are consistent with JP=1+for Zb(10610) & Zb(10650). All other JP with J2 are disfavored at typically 3 level. Probabilities at which different JPhypotheses are disfavored comparedto 1+ Preliminary: procedure to deal with non-resonant contribution is approximate, no mutual cross-feed of Zb’s

  29. Heavy quark structure in Zb A.B.,A.Garmash,A.Milstein,R.Mizuk,M.Voloshin PRD84 054010 (arXiv:1105.4473) Wave func. at large distance – B(*)B* 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 –”– • Existence of other similar states Predicts Other Possible Explanations • Coupled channel resonances (I.V.Danilkin et al, arXiv:1106.1552) • Cusp (D.Bugg Europhys.Lett.96 (2011),arXiv:1105.5492) • Tetraquark (M.Karliner, H.Lipkin, arXiv:0802.0649)

  30. Observation of hb(1P)b(1S) 

  31. Introduction to b Expected decays of hb Godfrey & Rosner, PRD66 014012 (2002) hb(1P) → ggg (57%), b(1S) (41%), gg (2%) hb(2P) → ggg (63%), b(1S) (13%), b(2S) (19%), gg (2%) Large hb(mP) samples give opportunity to study b(nS) states. (3S)  b(1S)  Experimental status of b M[b(1S)] = 9390.9  2.8 MeV (BaBar + CLEO) M[(1S)] – M[b(1S)] = 69.3  2.8 MeV pNRQCD: 4114 MeV Lattice: 608 MeV Kniehl et al., PRL92,242001(2004) Meinel, PRD82,114502(2010) Width of b(1S): no information

  32. + (5S)  Zb- M(b) Method Decay chain reconstruct  hb (nP) + Use missing massto identify signals  b(mS)  MC simulation true +- fake  true +- true  fake +- true  M(hb)

  33. + (5S)  Zb- M(b) Method Decay chain reconstruct  hb (nP) + Use missing massto identify signals  b(mS)  MC simulation Mmiss(+-)  Mmiss(+-) – Mmiss(+-) + M[hb] true +- fake  true +- true  fake +- true  M(hb)

  34. + (5S)  Zb- M(b) Method Decay chain reconstruct  hb (nP) + Use missing massto identify signals  b(mS)  MC simulation Mmiss(+-)  Mmiss(+-) – Mmiss(+-) + M[hb] Approach: fit Mmiss(+-) spectrain Mmiss(+-) bins hb(1P) yield vs. Mmiss(+-)  search for b(1S) signal M(hb)

  35. Results N.Brambilla et al., Eur.Phys.J. C71(2011) 1534 (arXiv:1010.5827) b(1S) pNRQCD Lattice 13 BaBar (3S)  b(1S)  BaBar (2S) CLEO (3S) BELLE preliminary MHF [b(1S)] = 59.3  1.9 +2.4 MeV/c2 –1.4 potential models :  = 5 – 20 MeV Godfrey & Rosner : BF = 41%

  36. Summary First observation of hb(1P) and hb(2P) arXiv:1103.3419 accepted by PRL Hyperfine splitting consistent with zero, as expectedAnomalous production rates Observation of two charged bottomonium-like resonances in 5 final states arXiv:1105.4583, arXiv:1110.2251, accepted by PRL (1S)π+, (2S) π+, (3S)π+,hb(1P)+, hb(2P)+ M = 10607.2  2.0 MeV  = 18.4 2.4 MeV M= 10652.2  1.5 MeV  = 11.5  2.2 MeV Zb(10610) Zb(10610) Masses are close to BB* and B*B* thresholds – molecule? Angular analyses favour JP= 1+ , decay pattern IG = 1+ Observation of hb(1P)b(1S) arXiv:1110.3934 The most precise single meas., significantly different from WA,decreases tension w/ theory Will Zb’s become a key to understanding of all other quarkonium-like states?

  37. Back up

  38. arXiv:1105.5829 12GeV U(?S) 11.5GeV U(6S) h U(5S) r w g r r p w g B*B* w Up hbphbr Ur Ur hbp Uh hbw Uw hbh Uw g BB* g Ur Uw BB Wb1 Xb Wb2 Wb0 Zb 0-(1+) IG(JP) 1+(1+) 0+(0+) 1-(0+) 0+(1+) 1-(1+) 0+(2+) 1-(2+) 0-(1-)

  39. Coupled channel resonance? I.V.Danilkin, V.D.Orlovsky, Yu.Simonov arXiv:1106.1552 No interaction between B(*)B* or  is needed to form resonance No other resonances predicted B(*)B* interaction switched on individual mass in every channel?

  40. Cusp? D.Bugg Europhys.Lett.96 (2011) (arXiv:1105.5492) Line-shape Amplitude Not a resonance

  41. Tetraquark? Ying Cui, Xiao-lin Chen, Wei-Zhen Deng, Shi-Lin Zhu, High Energy Phys.Nucl.Phys.31:7-13, 2007 (hep-ph/0607226) M ~ 10.2 – 10.3 GeV M ~ 10.5 – 10.8 GeV Tao Guo, Lu Cao, Ming-Zhen Zhou, Hong Chen, (1106.2284) M ~ 9.4, 11 GeV M.Karliner, H.Lipkin, (0802.0649)

  42. + (5S)  Zb- Selection Decay chain reconstruct  hb (nP) +  b(mS)  R2<0.3 Hadronic event selection; continuum suppression using event shape; 0 veto. Require intermediate Zb :10.59 < MM() < 10.67 GeV bg. suppression 5.2 Zb

  43. Mmiss(+-) spectrum requirement of intermediate Zb Update of M [hb(1P)] : MHF [hb(1P)] = (+0.8  1.1)MeV/c2 Previous Belle meas.: arXiv:1103.3411 hb(1P) (2S) MHF [hb(1P)] = (+1.6  1.5)MeV/c2 3S1S

  44. Results of fits to Mmiss(+-) spectra hb(1P) yield b(1S) Peaking background? MC simulation  none. (2S) yield no significant structures Reflection yield

  45. B+ c1 K+  (J/ ) K+ Use decays cosHel (c1)> – 0.2 match  energy of signal &callibrationchannels Calibration Photon energy spectrum MC simulation hb(1P)b(1S) c1  J/ cosHel >–0.2

  46. mass shift –0.7  0.3 +0.2 MeV –0.4 Calibration (2) Resolution: double-sided CrystalBall function with asymmetric core data E s.b. subtracted M(J/), GeV/c2  Correction of MC fudge-factor for resolution 1.15  0.06  0.06

  47. Integrated Luminosity at B-factories (fb-1) asymmetric e+e- collisions > 1 ab-1 On resonance: (5S): 121 fb-1 (4S): 711 fb-1 (3S): 3 fb-1 (2S): 24 fb-1 (1S): 6 fb-1 Off reson./scan : ~100 fb-1 Bs 530 fb-1 On resonance: (4S): 433 fb-1 (3S): 30 fb-1 (2S): 14 fb-1 Off reson./scan : ~54 fb-1

  48. e+e- hadronic cross-section BaBar PRL 102, 012001 (2009) (1S) (5S) (6S) (4S) (2S) (3S) (4S) Belle took data at E=108671MэВ 2M(B) 2M(Bs) _ e+ e- ->(4S) -> BB,whereBisB+orB0 _ _ _ _ _ e+ e- -> bb ((5S)) ->B(*)B(*), B(*)B(*)p, BBpp, Bs(*)Bs(*), (1S)pp, X … main motivation for taking data at (5S)

  49. Description of fit to MM(+-) Three fit regions Example of fit 1 2 3 BG: Chebyshev polynomial, 6th or 7th order Signal: shape is fixed from +-+- data “Residuals” – subtract polynomial from data points KS contribution: subtract bin-by-bin (1S) Residuals kinematicboundary M(+-) Ks generic (3S) MM(+-) MM(+-)

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