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

3 PRL100,112001(2008)  (MeV) 10 2 PRD82,091106R(2010) Anomalous production of  (nS)  +  - 1. Rescattering  (5S)  BB  (nS)  ? Simonov JETP Lett 87,147(2008) 2. Similar effect in charmonium?  shapes of R b and  (  ) different (2  ) to distinguish  energy scan  (5S) line shape of Y b Y(4260) with anomalous  (J/   +  - )  assume  Y b close to  (5S)

4 h b (1P) & h b (2P) Observation of

5 Trigger Y(4260)  Y b  search for h b (nP)  +   (5S) CLEO observed e + e - → h c  +  E CM =4170MeV PRL107, (2011)  (h c  +  – )   (J/   +  – ) 4260 Hint of rise in  (h c  +  - Y(4260) ? Y(4260)

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

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

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

9 Results fb -1 h b (1P) 5.5  h b (2P) 11.2  Significance w/ systematics

10 Hyperfine splitting h b (1P) (1.7  1.5) MeV/c 2 h b (2P) ( ) MeV/c Deviations from CoG (Center of Gravity) of  bJ masses consistent with zero, as expected Ratio of production rates  Mechanism of  (5S)  h b (nP)  +  - decay violates Heavy Quark Spin Symmetry for h b (1P) for h b (2P) no spin-flip = spin-flip Process with spin-flip of heavy quark is not suppressed

11 Resonant structure of  (5S)  h b (nP)  +  -

12 Resonant structure of  (5S)  h b (1P)  +  - M(h b  – ), GeV/c 2 phase-space MC M(h b  + ), GeV/c 2

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

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

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

16  (5S)   (nS)  +  -  +- +- (n = 1,2,3)  (1S)  (2S)  (3S) reflections M miss (  +  - ), GeV/c 2

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

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

19  (5S)  (nS)  +  - Dalitz plots  (1S)  (2S)  (3S)  Signals of Z b (10610) and Z b (10650)

20 heavy quark spin-flip amplitude is suppressed Fitting the Dalitz plots Signal amplitude parameterization: S(s1,s2) = A(Z b1 ) + A(Z b2 ) + A(f 0 (980)) + A(f 2 (1275)) + A NR A NR = C 1 + C 2 ∙m 2 (ππ) Parameterization of the non-resonant amplitude is discussed in [1] M.B. Voloshin, Prog. Part. Nucl. Phys. 61:455, [2] M.B. Voloshin, Phys. Rev. D74:054022, A(Z b1 ) + A(Z b2 ) + A(f 2 (1275)) A(f 0 (980)) – Breit-Wigner – Flatte  (5S)  Z b , Z b   (nS)  – no spin orientation change S-wave Spins of  (5S) and  (nS) can be ignored Angular analysis favors J P =1 + Non-resonant

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

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

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

24  M 1  =  2.0 MeV   1  = 18.4  2.4 MeV  M 2  =  1.5 MeV   2  = 11.5  2.2 MeV Summary of Z b parameters Average over 5 channels

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

26 Angular analysis

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

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

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

30 Observation of h b (1P)  b (1S) 

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

32 Method reconstruct   b (mS)   (5S)  Z b  - +  h b (nP)  + Decay chain Use missing mass to identify signals M(  b ) M(h b ) true  +  - fake  fake  +  - true  true  +  - true  MC simulation

33 Method reconstruct   b (mS)   (5S)  Z b  - +  h b (nP)  + Decay chain Use missing mass to identify signals M(  b ) M(h b ) true  +  - fake  fake  +  - true  true  +  - true  MC simulation  M miss (  +  -  )  M miss (  +  -  ) – M miss (  +  - ) + M[h b ]

34 Method reconstruct   b (mS)   (5S)  Z b  - +  h b (nP)  + Decay chain Use missing mass to identify signals M(  b ) M(h b ) MC simulation  M miss (  +  -  )  M miss (  +  -  ) – M miss (  +  - ) + M[h b ] Approach: fit M miss (  +  - ) spectra in  M miss (  +  -  ) bins  h b (1P) yield vs.  M miss (  +  -  )  search for  b (1S) signal

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

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

37 Back up

38  (5S)  (6S)  (?S) I G (J P ) B*B* BB* BB 0 - (1 + ) 1 + (1 + ) 0 + (0 + )1 - (0 + )0 + (1 + )1 - (1 + )0 + (2 + )1 - (2 + )         12GeV 11.5GeV  ZbZb W b0 W b1 W b2     h b   b    b    b    b      arXiv: XbXb 0 - (1 - )

39

40 Coupled channel resonance? I.V.Danilkin, V.D.Orlovsky, Yu.Simonov arXiv: 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?

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

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

43 Selection Require intermediate Z b : < MM(  ) < GeV ZbZb Hadronic event selection; continuum suppression using event shape;  0 veto. R 2 <0.3 reconstruct   b (mS)   (5S)  Z b  - +  h b (nP)  + Decay chain bg. suppression  5.2

44 M miss (  +  - ) spectrum requirement of intermediate Z b Update of M [h b (1P)] : Previous Belle meas.: h b (1P) 3S  1S  (2S)  M HF [h b (1P)] = (+0.8  1.1)MeV/c 2  M HF [h b (1P)] = (+1.6  1.5)MeV/c 2 arXiv:

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

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

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

48 BsBs Integrated Luminosity at B-factories > 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 fb -1 On resonance:  (4S): 433 fb -1  (3S): 30 fb -1  (2S): 14 fb -1 Off reson./scan : ~54 fb-1 (fb -1 ) asymmetric e + e - collisions

49  ( 5S ) Belle took data at E=10867  1 MэВ 2M(B s ) BaBar PRL 102, (2009)  ( 6S )  ( 4S ) e + e - hadronic cross-section main motivation for taking data at  (5S)  ( 1S )  ( 2S )  ( 3S )  ( 4S ) 2M(B) e + e - ->  (4S) -> BB, where B is B + or B 0 e + e - -> bb (  (5S)) -> B ( * ) B ( * ), B ( * ) B ( * ) , BB , B s ( * ) B s ( * ),  (1S) ,  X … _ _____

50 Residuals  (1S) Example of fit Description of fit to MM(  +  - ) Three fit regions 123 Ks generic  (3S) kinematic boundary MM(  +  -) M(  +  -) MM(  +  -) BG: Chebyshev polynomial, 6 th or 7 th order Signal: shape is fixed from  +  -  +  - data “Residuals” – subtract polynomial from data points K S contribution: subtract bin-by-bin

Y(5S) → Y(2S)π + π - Results: Y(5S) → Y(2S)π + π - 51

Y(5S) → Y(2S)π + π - Results: Y(5S) → Y(2S)π + π - 52