1 Тяжелый кварконий, эксперимент Р.В. Мизюк (ИТЭФ) Сессия-конференция секции ЯФ ОФН РАН "Физика фундаментальных взаимодействий“ 23 ноября 2011г., ИТЭФ Коллаборация BELLE

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

3 QWG, arXiv: Charmonium table below DD threshold is completed J PC M, GeV Renaissance in quarkonium n (2S+1) L J spectroscopic notation P = (–1) L+1 C = (–1) L+S J PC conserved QN _

4 Many new states do not fit qq table… QWG, arXiv: _

5 Close to D* 0 D 0 threshold:  m = – 0.09  0.34 MeV  M  =  0.19 MeV, Γ < 1.2 MeV (90% C.L.) QWG, arXiv: Many new states do not fit qq table… _ J PC = 1 ++ (2 –+ not excluded) Decay modes BF relative to J/   0 J/   0 1 J/   0.8  0.3 J/   0.21  0.06 D* 0 D 0 ~10 Interpretation: D* 0 D 0 molecule _ D* 0 D 0 lineshape crucial for structure : _ bound / virtual state admixture of  c1 ′ BF(J/  0 ) > 2.5% (90% C.L.)

6 QWG, arXiv: Many new states do not fit qq table… _ Z(4430) + widths 100–200 MeV  difficult to interpret multiquark candidates BZKBZK rescattering? Pakhlov PLB702,139(2011)

7 QWG, arXiv: Many new states do not fit qq table… _ Y(4260) BaBar  (Y 4260      J/  ) > % CL X.H.Mo et al, PL B640, 182 (2006) cf.  (        J/  ) = 0.04 MeV 4260  (e+e-  hadrons)  (e+e-   +  -) BES data No sign of Y(4260)  D ( * ) D ( * ) _ e + e -  ISR  +   J/ 

8 QWG, arXiv: 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) Many new states do not fit qq table… _

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

10 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)

11 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 arXiv:  Previous search

12 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 arXiv:  Previous search 

13  (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)

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

15 Hyperfine splitting h b (1P) (1.6  1.5) MeV/c 2 h b (2P) ( ) MeV/c Deviations from CoG of  bJ masses consistent with zero, as expected Ratio of production rates  Mechanism of  (5S)  h b (nP)  +  - decay is exotic for h b (1P) for h b (2P) no spin-flip = spin-flip Process with spin-flip of heavy quark is not suppressed

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

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

18 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 =  = degree 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)

19 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 degree 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 =  = degree MeV

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

21  (5S)   (nS)  +  -  +- +- (n = 1,2,3)  (1S)  (2S)  (3S) reflections M miss (  +  - ), GeV/c 2

22  (1S)  (2S)  (3S)  (5S)   (nS)  +  -  (nS)   +  - (n = 1,2,3) M miss (  +  - ), GeV/c 2 purity 92 – 94%

23  (5S)  (nS)  +  - Dalitz plots  (1S)  (2S)  (3S)

24  (5S)  (nS)  +  - Dalitz plots  (1S)  (2S)  (3S)  Signals of Z b (10610) and Z b (10650)

25 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

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

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

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

29  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

30  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

31 Angular analyses

32 Angular analyses 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

33 Summary of angular analyses 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:

34 Heavy quark structure in Z b Wave func. at large distance – B(*)B* 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

35

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

37 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)

38 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 ]

39 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

40 Results  b (1S) 13  potential models :  = 5 – 20 MeV Godfrey & Rosner : BF = 41% BaBar  (3S)   b (1S)  BaBar  (2S) CLEO  (3S) BELLE preliminary pNRQCDLattice arXiv:  M HF [  b (1S)] = 59.3  MeV/c 2 –1.4

41 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: , submitted to 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)

42 Back up

43 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

44  ( 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 … _ _____

45 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

46 Why do we think these are h b (nP) and not  b1 (nP) ? Masses are significantly different: The strong decay  (5S)   b1  +  - violates isospin conservation  M(1P) =  5.5  1.6 (3.5  )  M(2P) =  4.3  1.4 (3.2  ) Search in  (4S) data No significant signal of h b (1P):   (4S) does not show anomalous properties L = 711fb -1 [  6  (5S) sample]  [e + e -  h b (1P)  +  -  (4S)  [e + e -  h b (1P)  +  -  (5S) <0.28 at 90%C.L.

47 Confidence Levels of angular fits to  (5S)  Z b +  -  [h b (1P)  + ]  - decay with hypothesis 1+