Bottomonium physics at Y(4S,5S,6S) with Belle

Transcription

1 Bottomonium physics at Y(4S,5S,6S) with Belle Umberto Tamponi INFN, Sezione di Torino University of Torino Fairness 2016 Garmisch-Partenkirchen, 02/15/2016

2 The KEKB complex For a summary of Belle's resuts: Prog. Theor. Exp. Phys. (2012) 04D001 e ~8 GeV B Y(4S) e+ B Y(1S) 5.7 fb 1 Y(2S) 24 fb 1 Y(3S) 3 fb 1 R Lmax = 2.11 x 1034 cm 2 s 1 Off 89 fb 1 ~3.5 GeV LAB to CM boost Complete knowledge of initial state Y(4S) 711 fb 1 Y(5S) 121 fb 1 ~ 1 ab of e+e events World largest samples of Y(1S), Y(2S), Y(4S), Y(5S) and off resonance ~ 770 M of of Y(4S) BB events 1

3 The Belle detector Calorimeter Inner tracking: 3 4 layers of Double Sided Silicon Strip Drift chamber (traking + de/dx) Particle Identification: Time of flight (TOF) Threshold Cherenkov counter Neutrals: NaI(Tl) calorimeter RPC + Fe for KL conversions PID Drift Chamber Silicon vertex 2

4 Part I Energy scans

5 Mass [GeV] Threshold structure in bottomonium Non-relativistic potential 11 Y(6S) 10.8 Unresolved triplets BaBar scan Observed states Y(5S) PRL102: (2009) 10.6 η (4S) Y(4S) b χbj (3P) 10.4 h b (3P) 3 Y(21D) Y(13DJ ) Y(11D) Y(2 DJ ) Y(3S) η (3S) b 10.2 h b (2P) χbj (2P) 10 Y(2S) η (2S) b 9.8 h b (1P) χbj (1P) 9.6 Theoretical predictions from Eur. Phys. J. C72 (2012), Issue 4, Y(1S) η (1S) b JP C 1 3 S1 0 1 S0 + 0,1,2+ 3 P0,1, P1 + 1,2,3 3 D1,2, D2 Bottomonium is intrinsically non relativistic no mixing simpler than charmonium good description of the cross section sin terms of Rb + [e e bb hadrons] Rb = [e+e ] 3

6 Y(5S) lineshape history Both open and close PRD 89, (2010) ~1 fb 1/point SCAN + [e e bb hadrons] Rb = [e+e ] Y(5S) Y(6S) + [e e Y(nS)] R = [e+e ] Y(5S) (a.k.a. Yb) PRL 102, (2009) BaBar Belle 2010 M(5S)bb = MeV M(5S) = MeV M(5S) M(5S) = 9 4 MeV 4

7 New Belle Y(5S) scan Full Belle scan For Rb: 61 points (50/pb each) every 5 MeV For R : 22 points (1/fb each) According to PRL 102, (2009) cross sections are visible ones, not Born 5

8 New Belle Y(5S) scan Same as PRL 102, (2009) Coherent continuum Amplitude Y(5S) relativistic Breit Wigner Y(6S) relativistic Breit Wigner According to BaBar's analysis,continuum is assumed to be flat Incoherent continuum Amplitude M(5S)bb = MeV Y(5S) fitted mass Y(5S) fitted mass preliminary (5S)bb = 51 2 MeV BaBar, same fit M(5S)bb = MeV M(6S)bb = MeV Rb maxima (6S)bb = 40 2 MeV 6

9 R at Belle ArXiv: [e e Y(nS)] R = [e+e ] Full reconstruction of Y No continuum background e+e + suppression: sidebands Y(1S) Y(2S) Y(3S) Y(5S) mass 7

10 R at Belle ArXiv: No continuum contribution is visible Y(6S) Y(1S) Fixed by Rb Y(6S) Y(1,2,3S) First Evidence M(5S) = ± 1.4 ± 1.2 MeV (5S)bb = 51 ± 5 ± 5 MeV Y(2S) M(5S) M(5S)bb = 4.4 ± 2.5 MeV (1.8 ) (5S) (5S)bb = 0 ± 8 MeV The discrepancy between Rb and R is not striking R seems to be more reliable Y(3S) Y(5S) mass 8

11 R with hb(1,2p) ArXiv: Y(5S) hb(1p) was observed. Reconstructed e Y(5S) Y(6S) Y(6S) hb(1p, 2P) First Evidence! Mass [GeV] does it behave like Y(nS)? what about the Y(6S)? e+ hb(1,2p) Not Reconstructed Non-relativistic potential 11 Y(6S) 10.8 Unresolved triplets Observed states Y(5S) 10.6 η (4S) Y(4S) b χbj (3P) 10.4 h b (3P) 3 Y(21D) Y(13DJ ) Y(11D) Y(2 DJ ) Y(3S) η (3S) b 10.2 h b (2P) χbj (2P) 10 Y(2S) η (2S) b 9.8 h b (1P) χbj (1P) hadrons 9.6 Theoretical predictions from Eur. Phys. J. C72 (2012), Issue 4, Y(1S) η (1S) b JP C 1 3 S1 0 1 S0 + 0,1,2+ 3 P0,1, P1 + 1,2,3 3 D1,2, D2 9

12 R with hb(1,2p) Is there any Zb signal? single pion recoil mass Y(5S) Y(6S) arxiv: First evidence of resonant structures in Y(6S) pp bb Transition dominated by the Zb contributions 10

13 Part II New transitions

14 Hadronic transitions: lower states Kuang, Front.Phys.China 1, 19 (2006) QED multipole expansion a/ ~ ak < 1 Photon momentum k a Two step process with emission of gluon pairs In quarkonia: r ~ 0.1 fm rk < 1 k ~ 100 MeV Chromo electric gluons (no spin flipping) Chromo magnetic gluons (spin flipping) Color octet, Intermediate states can be factorized First gluon emission QQg hybrid states Second gluon emission A potential model may enter here Gluons hadrons 11

15 HQSS above the threshold Heavy Quark Spin Symmetry predicts: b quark Γ [Y (ns) η Y (ms)] spin flip 1 Γ[Y (ns) π π Y (ms)] no b quark spin flip Γ[Y (ns) π π h b (mp)] 1 Γ[Y (ns) π π Y (ms)] Below threshold ~ OK B[Y (3 S) ηy (1 S)] < B [Y (3 S) π π Y (1 S)] B[Y (2 S) ηy (1 S)] 3 =(1.64±0.25) 10 B [Y (2 S) π π Y (1 S)] QCDME 12

16 HQSS above the threshold Heavy Quark Spin Symmetry predicts: b quark Γ [Y (ns) η Y (ms)] spin flip 1 Γ[Y (ns) π π Y (ms)] no b quark spin flip Γ[Y (ns) π π h b (mp)] 1 Γ[Y (ns) π π Y (ms)] Γ [Y (5 S) ηy (1 S)] =0.16 Γ[Y (5 S) π π Y (1 S)] Belle preliminary Γ [Y (5 S) ηy (2 S)] =0.48 Γ[Y (5 S) π π Y (2 S)] Γ [Y (4 S) ηy (1 S)] =2.41±0.40±0.20 PRD 78, Γ[Y (4 S) π π Y (1 S)] Spin flipping transition is enhanced for transitions across the threshold should QCDME fail so badly? large transitions: source of SU(3) violation? Why enhancement at Y(4S)? QCDME 12

17 Missing transitions Unknown transitions from Y(5S) have been widely studied Known transitions to spin singlet states are still not studied Y(4S) Y(4S) hb(1p) predicted to have BF ~ 10 3 Known Y(5S) Possible new gateway to b(1s) Y(5S) hb(2p) can give indications on the HQSS breaking mechanism 14

18 Y(4S) bb Systematic uncertanties BF[Y(4S) hb(1p)] = ( )x10 3 First single meson, 3S 1P BF[Y(4S) Y(1S)] < 2.7 x 10 4 In agreement with previous results and simulation M(hb(1P) = ( ) MeV/c2 In agreement with previous measurement M(hb(1P) = ( ) MeV/c2 PRL 115, (2015) hb(1p) Y(1S) 15

19 Results: Y(5S) bb Assuming (e e Y(5S)) = (0.340 ± 0.016) nb + Systematic uncertanties BF[Y(5S) Y(2S)]=( ) x 10 3 BF[Y(5S) Y(1D)]=( ) x 10 3 BF[Y(5S) hb(1p)] < 3.3 x 10 3 (90% CL) BF[Y(5S) hb(2p)] < 3.7 x 10 3 (90% CL) Preliminary Y(1S) 1.8 hb(1p) 2.4 Y(2S) 3.3 Y(1D) 5.3 hb(2p) <1 16

20 transitions: Th. VS Exp Y(2,3S) Y(4S) Y(5S) transitions transitions 17

21 transitions: HQSS Γ [Y (4 S) η hb (1 P)] >5.4 Γ[Y (4 S) π π h b (1 P)] Γ [Y (5 S) ηh b (1 P)] <0.94 Γ[Y (5 S) π π hb (1 P)] Γ [Y (5 S) ηh b (2 P)] <0.62 Γ[Y (5 S) π π hb (2 P)] Assuming BF[Y(4S) hb(1p)] =< 0.4 x10 3 Same behavior as in the Y(4S) Y(1S) transitions Spin flip / spin flip ratios No theoretical predictions transitions QCDME 18

22 Investigations on the static potential Eichten and Feinberg, PRD23, 2724 (1981) L Spin dependent potential as function of long range and short rage potentials S2 Mass [GeV] S1 Non-relativistic potential 11 Y(6S) 10.8 Unresolved triplets Observed states Y(5S) 10.6 η (4S) Y(4S) b χbj (3P) 10.4 P wave Odd r (0) MHF(1P) = MeV/c2 MHF(1P) = MeV/c2 MHF(2P) = MeV/c2 2 =0 PDG This work PDG 3 Y(21D) Y(13DJ ) Y(11D) Y(2 DJ ) Y(3S) η (3S) b 10.2 h b (2P) χbj (2P) 10 Y(2S) η (2S) b 9.8 hb (1P) Fine splitting Hyperfine splitting χbj (1P) 9.6 S wave Even r (0) 2 0 h b (3P) Theoretical predictions from Eur. Phys. J. C72 (2012), Issue 4, Y(1S) η (1S) b MHF(1S) = MeV/c2 PDG JP C 1 3 S1 0 1S + 0,1, P0,1, P1 + 1,2,3 3 D1,2, D2 19

23 1S HF puzzles 90 hb(1,2p) b(1s) v. (pri M1 Measurements of the ground state HF in different channels gave different results M( b)m1 M( b)e1 = 12 3 MeV M( c)m1 M( c)e1 = MeV.) av g (201 8) le Bel (200 ) 1) discrepancy ar BaB 10) 40 ( ar ( BaB 60 O CLE 1S Hyperfne splitting [MeV/c 2 ] Y(2,3S) b(1s) (2S) / J c(1s) B decays c pp c hc(1p) c(1s) 2) 201 III ( BES ) 009 O (2 CLE 03) ( 20 BES 00) ( 20 BES 00 ) ( 20 ) BES (2 E 83 1) 201 le ( 8) Bel 200 ar ( BaB 2) 201 le ( 11) Bel ( 20 ar BaB 10) ( 20 8) ar 200 BaB le ( Bel 04) 20 O ( CLE 20

24 1S HF puzzles 90 hb(1,2p) b(1s) ) av g (201 ) 1) 30 v. (pri M1 le Bel 8) 10) 40 (200 ( discrepancy ar BaB ar ( BaB O CLE 1S Hyperfne splitting [MeV/c 2 ] Y(2,3S) b(1s) 20 (2S) / J c(1s) B decays c pp c In charmonium, the discrepancy is corrected introducing a form factor for the M1 transitions M( c)line shape factor: 2 E 3γ exp( E 2 γ /(8 β )) = MeV PRL 102 (2009) , Erratum ibid. 106 (2011) Same factor for the b(1s)? hc(1p) c(1s) 2) 201 III ( BES ) 009 O (2 CLE 03 ) ( 20 BES 00) (20 BES 00 ) ( 20 ) BES (2 E 83 1) 201 le ( 8) Bel 200 ar ( BaB 2) 201 le ( 11) Bel ( 20 ar BaB 10) ( 20 8) ar 200 BaB le ( Bel 04) ( 20 O CLE (2S) / J c(1s) corrected 21

25 Y(4S) hb(1p) b(1s) Signal MC simulation MC arxiv: b hb Y(4S) b hb PRL 115, (2015) b(1s) hb(1s) = ( ) MeV b(1s) = ( ) MeV +6 b(1s) = (8 5) MeV 5 BF[hb(1P) b(1s)] = (56 8 4) % 22

26 le Bel ) (2 9) ) 01 ( ( PRL 2 1S Hyperfne splitting [MeV/c hb(1p) b(1s) le Bel 0 81, RD, Lattice PRL 81, Potential pnrqcd ar P BaB ar BaB P RD 20 O CLE 30 hb(1,2p) b(1s) Y(2,3S) b(1s) 2 t al hl e Knie pk o, Re 7 fo r d 2 00 Rad p ko, Re 3 fo r d 20 1 Rad t al ao e i Zh We 50 ne Mei s Aart 80 Tian t Al. ch e 012 Bur Al l et l 20 wal Rod ] 1S HF splitting theory VS experiment Belle Y(4S): MHF(1S) = ( ) MeV MHF(1P) = ( ) MeV Belle Y(5S): MHF(1S) = ( ) MeV MHF(1P) = ( ) MeV 23 16

27 Summary First observation of Y(4S) hb(1p) First study of Y(5S) hb(1p) Preliminary No evidences, but upper limits allows to increase our knowledge of the spin flipping transitions pattern Updated parameters of b(1s) Line shape factor as in charmonium? Fine graned Rb and R scan Evidence of Y(6S) Y(nS) Can Y(5S) Yb difference be due to interference with non flat continuum? R scan with hb(np) First evidence of Y(6S) hb(1p,2p) BelleII 50 ab 1 Y(4S) ~ 100 millions hb(1p) via transitions (untagged) 24

28 Backup

29 Heavy quark spin symmetry tests / transitions to spin singlets (first study) Γ [Y (5 S) ηh b (1 P)] <0.94 Γ[Y (5 S) π π hb (1 P)] Γ [Y (5 S) ηh b (2 P)] <0.62 Γ[Y (5 S) π π hb (2 P)] Γ [Y (4 S) η hb (1 P)] >5.4 Γ[Y (4 S) π π h b (1 P)] Spin flip / spin flip ratios No theoretical predictions Results on transition Y(5S) Y(1D) is estimated on published data Assuming BF[Y(4S) hb(1p)] =< 0.4 x10 3 Same behavior as in the Y(4S) Y(1S) transitions and ratios compared Non spin flip / spin flip Γ[Y (5 S) ηy (1 D)] >0.92 Γ[Y (5 S) η hb (1 P)] Γ[Y (5 S) π π Y (1 D)] 0.5 Γ[Y (5 S) π π hb (1 P)] Γ [Y (5 S) ηy (1 D)] >0.78 Γ[Y (5 S) η hb (2 P)] Γ [Y (5 S) π π Y (1 D)] 0.3 Γ[Y (5 S) π π hb (2 P)] Γ[Y (5 S) ηy (1 D)] =1.6±0.7 Γ[Y (5 S) ηy (2 S)] Γ[Y (5 S) π π Y (1 D)] 0.3 Γ[Y (5 S) π π Y (2 S)] Spin flip / spin flip. Theory? Non spin flip / non spin flip Expected to be small in HQSS Opposite behavior between and 41

30 R with hb(1,2p) ArXiv: Y(5S) hb(1p) was observed. does it behave like Y(nS)? what about the Y(6S)? e Reconstructed e+ hb(1,2p) Y(5S) Y(6S) Not Reconstructed Y(6S) hb(1p, 2P) First Evidence! Fit model: 8

31 R VS Rb 7

32 Zb decay modes Preliminary BB* B*B* BB* Recoil mass from B* system tags the other B Zb Z'b Z'b Y(5S) B*B* Z'b Zb B* B(*) 10

33 Zb decay modes preliminary Z'b B*B* Zb BB * From inclusive Y(5S) +X decays Kinematically favoured but absent Why Zb(10650) should not decay in BB*? Zb ~ BB *> Z'b ~ B*B* > Molecular Model with negligible BB*> component Proximity to open threshold (open flavour ) >> (narrow quarkonium) 11

34 HQSS above the threshold Heavy Quark Spin Symmetry predicts: b quark Γ [Y (ns) η Y (ms)] spin flip 1 Γ[Y (ns) π π Y (ms)] Γ[Y (5 S) π π hb (2 P)] =0.77± Γ[Y (5 S) π π Y (2 S)] Γ[Y (ns) π π h b (mp)] 1 Γ[Y (ns) π π Y (ms)] Γ[Y (5 S) π π hb (1 P)] 0.07 =0.46± Γ[Y (5 S) π π Y (2 S)] Mass [GeV] no b quark spin flip Non-relativistic potential 11 Y(6S) 10.8 Unresolved triplets Observed states Y(5S) 10.6 b χbj (3P) 10.4 h b (3P) 3 Y(21D) Y(13DJ ) Y(11D) Y(2 DJ ) Y(3S) η (3S) b 10.2 h b (2P) χbj (2P) 10 Y(2S) 9.8 hb (1P) χbj (1P) 9.6 Theoretical predictions from Eur. Phys. J. C72 (2012), Issue 4, 1981 Y(1S) η (1S) b JP C 1 3 S1 Γ [Y (5 S) ηy (1 S)] =0.16 Γ[Y (5 S) π π Y (1 S)] Belle preliminary Γ [Y (5 S) ηy (2 S)] =0.48 Γ[Y (5 S) π π Y (2 S)] Γ [Y (4 S) ηy (1 S)] PRD 78, =2.41±0.40± Γ[Y (4 S) π π Y (1 S)] η (2S) b 9.4 PRL108, Y(4S): spin flip enhancement η (4S) Y(4S) Y(5S): no spin flip suppression 0 1S 0 + 0,1,2+ 3 P0,1, P1 + 1,2,3 3 D1,2, D2 Spin flipping transition is enhanced for transitions across the threshold should QCDME fail so badly? large transitions: source of SU(3) violation? Why enhancement at Y(4S)? 13

35 Other exotics in Y(5S) transitions? Bottomonium equivalent of X(3872) CMS: inclusive search for PLB 727 (2013) 57 Xb Y(1S) in pp collisions Belle: exclusive Y(5S) decay Y(5S) Xb Y(1S) arxiv: BB threshold region Xb b(1p) Reflection! No b(3p) No Xb 35 12

36 Y(5S) b(1p) arxiv: B[Y(5S) b0(1p)] < 3.9 x 10 3 b(1p) B[Y(5S) b1(1p)] = x 10 3 B[Y(5S) b2(1p)] = x 10 3 B[Y(5S) Xb Y(1S)] < x

37 Rb versus R Rb an R are not independent Rb includes contribution form Y(nS) Rb includes contribution form hb(np) Pb = A5S(bb) x BW(5S) 2 bb contribution Y(nS) P( ns) = PHSP x A5S(nS) x BW(5S) 2 contribution Adding Y(5S) h (1,2P): P( bb) = (33 ± 7.5) % of Pb Assuming Isospin simmetry: P( bb) = (50 ± 14) % of Pb Adding Z B B : P( bb + Zb) = (132 36) % of Pb From R : P( ns) = (20 ± 6) % of Pb b (*) (*) b No or little room for Y(5S) BB*, BB, B*B*, BsBs direct decays these events come either from continuum, or from Zb decay Small interference between Y(5S) and continuum (different final states) Large interference Flat continuum is a crude approximation Resonance parameters from R are likely more reliable 15

38 The first B-Factory generation Remarkable discoveries Z(4430) Y(4S) Y(nS) X(3872) Y(5S) Y(nS) b(2s) Y(4S) hb(1p) hb(1p, 2P) Zb b(1s) Z(3900) / BESIII

39 Zb in Y(nS) final states PRL108, Y(nS) Clean final state Pure Y(nS) sample recoil tag 3 other observation of Zb's! PRL108, Belle has discovered two charged resonances: Zb bottomonium like simultaneous discovery of hb(1,2p) The states are observed in 5 final states, all with consistent masses, close to the BB* and B*B* threshold. M2(Y(1S) ) Analysis of angular distributions suggests JP=1+ for these states. ArXiV:hep ex/ , to PRL

40 Zb Summary PRL108, Mass and measured in 5 different final states agree Angular analysis suggests JP = 1+ Zb(10610) M = pm 2.0 MeV = 15.6 pm 2.5 MeV Zb(10650) M = pm 1.5 MeV = 14.4 pm 3.2 MeV The Di Pion transitions from the Y(5S) proceed via the intermediate charged state Zb The transition does not imply spin flip Masses are close to B*B and B*B* theresholds Molecules? The Y(5S) is an unexpected source of hb

41 Y(5S) Y(1D) PRL108, Y(2S) Y(1D) Preliminary Y(2S) Y(1S) simultaneous discovery of hb(1,2p) final state Significance 9 An evidence of Y(1D) was seen in inclusive MM( ) spectra Significance 2.9 B[Y(5S) Y(1D) ] B[Y(1D) b(1p) Y(1S) ] = ( ) 10 4

42 Y(5S) (bb): the Zb PRL108, M2(Y(1S) ) Dalitz analysis of Y(5S) Y(nS) ( ) ± 1.5 MeV Z'b B*B* 2 ± 2.2 MeV Open questions about Y(5S) Two peaks? Narrow state at Spin flipping amplitudes: transitions? ± 0.4 MeV Zb BB * 2 ± 2 MeV Open questions about Zb charged (minumum 4 quark content) close to B*B* an BB* thresholds ± 2 MeV ± 0.4 GeV 5

43 Quarkonium: the general picture Confinement Bound state of two heavy quarks S1 S2 Broad states: decay into open flavor ~ 100% 1 gluon exchange Mass [GeV] L Non relativistic regime <v2(c)> ~ 0.3 c2 <v2(b)> ~ 0.1 c2 Non-relativistic potential 11 Y(6S) 10.8 Unresolved triplets Observed states Y(5S) 10.6 η (4S) Y(4S) b χbj (3P) 10.4 Classic rules about hadronic transitions: Transitions across the BB threshold are suppressed (OZI rule) Heavy Quark Spin Symmetry (HQSS) is preserved 3 Y(21D) Y(13DJ ) Y(11D) Y(2 DJ ) Y(3S) Narrow states: decay with transitions or annihilations in light hadrons h b (3P) η (3S) b 10.2 h b (2P) χbj (2P) 10 Y(2S) η (2S) b 9.8 hb (1P) χbj (1P) 9.6 Theoretical predictions from Eur. Phys. J. C72 (2012), Issue 4, Y(1S) η (1S) b JP C 1 3 S1 0 1S + 0,1, P0,1, P1 + 1,2,3 3 D1,2, D2 2

44 hb (1P,2P) η b (1S,2S) PRL109 (2012) PRL108, hb(1,2p) is predicted to have large BF BF[hb(1P) ηb(1s)] = 41% BF[hb(2P) ηb(1s)] = 63% BF[hb(2P) ηb(2s)] = 13% Zb for radiative decays to ηb JP=1+ O(104) larger than in the Y(nS) system simultaneous discovery of hb(1,2p) Clean experimental signature with the hb(1,2p) and Zb tagging Means Less background than in the inclusive searches from Y(2,3S) Y(3S) γ η b (1S)

45 Y(5S) η Y(1,2S) PRL108, { Exclusive reconstruction Y(1,2S) + Y(2S) Y(1S) B[Y(5S) Y(1S) ] = ( ) 10 4 B[Y(5S) Y(2S) ] = (38 4 5) 10 MM( ) Preliminary 4 Preliminary simultaneous discovery of hb(1,2p) M( ) Preliminary 45

46 Missing Mass technique Y(5S) produced at rest in the colliding e+e frame reconstructed 2 * M(hb) = Ec.m. E + )2 p + - Known Measured Mmiss( + -)

47 Belle Y(5S) scan Full Belle scan For Rb: 61 points (50/pb each) every 5 MeV For R : 22 points (1/fb each) Both open and close [e e bb hadrons] Rb = [e+e ] + e+e qq suppression: R2 D. Santel, LLWS 2014 According to PRL 102, (2009) cross sections are visible ones, not Born + [e e Y(nS)] R = [e+e ] e+e + suppression: sidebands D. Santel, LLWS

48 Exclusive b(2s) at Belle arxiv: Identical reconstruction modes Y(2S) b(2s) Hadrons b(1p) Hadrons 25 fb 1 at Y(2S) energy (158 M Y(2S) decays, 16x CLEO) 87 fb 1 below Y(4S) energy for the study of the contiuum background study b(2s) claim by Dobbs et Al. is disconfirmed by Belle. BF[Y(2S) b(2s)] x BF[ b(2s) had] < 4.9 x 10 6 ~ one order of magnitude below the claim by Dobbs et at

49 hb(1p) at BaBar 3 sigma evidence: e+e Y(3S) π0hb Phys.Rev.D (R)

50 Spin-parity of the Zb New study of spin parity with a 6 D fit that includes contributions from non resonant S and D waves: S(s1,s2) = A(Zb) + A(Z'b) + A(f0(980)) + A(f2(1275)) + A(NR)+ A( ) Breit Wigner Flatte Breit Wigner Breit Wigner c1 +c2m2( ) Fit projections in M(Y(nS) ) 1+ is assigned unambiguously

51 Search for Zb0 arxiv: Y(5S) Y(nS) e+e, BF[Y(5S) Y(1S)] = (2.25 ± 0.11 ± 0.20) x 10 3 BF[ ] = (4.45 ± 0.16 ± 0.35) x 10 3 BF[Y(5S) Y(2S)] = (3.79 ± 0.24 ± 0.49) x 10 3 BF[ ] = (7.97 ± 0.31 ± 0.96) x 10 3 BF[Y(5S) Y(3S)] = (2.09 ± 0.51 ± 0.34) x 10 3 BF[ ] = (2.88 ± 0.19 ± 0.36) x 10 3 Isospin symmetry : BF[ ] = 2x BF[ ] OK

52 Search for Zb0 arxiv: Again multidimensional fit that includes contributions from non resonant S and D wave S(s1,s2) = A(Zb) + A(Z'b) + A(f0(980)) + A(f2(1275)) + A(NR) Significance is calculated from the Multi dimensional fit Z0b(10610): 6.5 [4.9 from Y(2S) from Y(3S) ] Z0b(10650): not observed but not excluded either Observed

53 Rη, ππ ratio PDG 2014 Voloshin 2006 Kuang 2006 Chao

54 Hadronic transitions: lower states Kuang, Front.Phys.China 1, 19 (2006) QED multipole expansion a/ ~ ak < 1 Photon momentum k a In quarkonia: r ~ 0.1 fm rk < 1 k ~ 100 MeV b r b Gluon momentum k hep-ph/ (QUARKS-2004) -1 r [ MeV ] Radius (potential model) Frascati Phys.Ser. 46 (2007) P D 2P S 1P 200 MeV 3S 2D 2S 300 MeV 500 MeV 1S 1000 MeV kxr= Mass [GeV/c ] Heavy quark spin symmetry: Transitions involving spin flipping amplitudes are suppressed QCDME natural limitations Power expansion breaks with increasing mass what happens above the threshold? 3