Quarkonium Production and Decay

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1 Quarkonium Production and Decay (Selected Topics in QQ ) Richard S. Galik Cornell University Physics in Collision 2004 Boston University June 2004

2 Why Study Quarkonia (bound states of qq )? the QCD equivalent of positronium simplest strongly interacting systems non-relativistic for heavy quarks (QQ): Q=c: β 2 ~ 0.25; Q=b: β 2 ~ 0.08 V(r) = -4/3 α s /r + k r (free v. confined) Wells much deeper than for QED mportant tests of Lattice QCD techniques 27 June 2004 Richard S. Galik 2

3 ~ 750 MeV ~ 1250 MeV The Heavy Quarkonia Spectra Charmonium Bottomonium Rich spectroscopy, various production schemes, interesting decay scenarios 27 June 2004 Richard S. Galik 3

4 Quarkonium Working Group CERN Yellow Report based on first two workshops available this summer!!! Followed (12-15 Oct) by QWG Wkshp 27 June 2004 Richard S. Galik [ 4

5 Large new datasets from e + e - machines on the 1 -- vector states ψ 10 ψ J/ψ CLEO/c CUSB/CBAL BES BES DM2 MK ϒ(1S) ϒ(3S) ϒ(2S) Cleo/c Cleo CUSB/CBAL and many new contributions from B factories and hadron colliders as well 27 June 2004 Richard S. Galik 5

6 News on the QQ Spin-Singlets Charmonium Bottomonium J PC = 0 + (η s) and 1 + (h s) 27 June 2004 Richard S. Galik 6

7 Production of QQ Spin-Singlets: as well as hadroproduction which is the most egalitarian! 27 June 2004 Richard S. Galik 7

8 QQ Spin-Singlets: bb (η b s and h b ): limits from CLEO in 03 no news h c ( 1 P 1, 1 +- ): not yet (maybe that is news?) η c ( 1 S 0, 0 -+ ): Ground state of charmonium Still only ~30% of decays known some updates New publ d mass determinations no big shifts Seen by CLEO in ψ γη c (>8σ) [LP03:hep-ph/ ] See QWG Yellow Report for up-to-date information 27 June 2004 Richard S. Galik 8

9 QQ Spin-Singlets: Biggest singlet news the (re)discovery of η c!! Four published observations: (Belle[2]/CLEO/BaBar) η c Belle B KX cc η c η c γγ K S Kπ η c but not seen by CLEO in radiative ψ decays, despite ~same sensitivity as Crystal Ball! η c J/ψ BaBar Belle PRL89(2002)102001, PRL89(2002) CLEO PRL92(2004) BaBar PRL92(2004) η c 9

10 Δ hf (spin-spin splitting) For J/ψ and η c, Δ hf is nicely established at 117 ± 2 MeV; deep in Coulombic QCD well ψ and η c sample the QCD confinement region. Δ hf = m(ψ ) - m(η c ) (MeV) Δ hf is 49 ± 2 MeV, or ~ half the value using the older CrystalBall η c mass!!! Older theory values seem high models assumed scalar QCD potential recent lattice (quenched) result gives Δ hf spanning MeV ball back in theorists court! [M. Okamoto, et al. PRD65, ] 27 June 2004 Richard S. Galik 10

11 Sampling of QQ Vector Results Charmonium Bottomonium J PC =1 directly produced in e + e - annihilation 27 June 2004 Richard S. Galik 11

12 B µµ for the ϒ States mportance beyond knowing B(ϒ(nS) µ + µ ) Needed to get Γ tot for narrow resonances from Γ ee ; CLEO hopes to measure Γ ee to a few percent Many analyses use the µ + µ final state for cleanliness; B µµ affects many branching fractions and partial widths [CLEO Scans] γ 27 June 2004 Richard S. Galik 12 µµ

13 Large signals in m µµ / s after continuum subtraction at the ϒ(1S), ϒ(2S), and even ϒ(3S) B µµ (ϒ(nS)) Data MC with µ FSR MC without µ FSR [CLEO Preliminary] and details such as muon FSR allow for high precision. 27 June 2004 Richard S. Galik 13

14 B µµ for the ϒ States [CLEO Preliminary] B µµ (%) Γ tot (kev) CLEO preliminary PDG CLEO preliminary PDG ϒ(1S) 2.53 ± 0.02 ± ± ± ± 1.8 ϒ(2S) 2.11 ± 0.03 ± ± ± ± 7 ϒ(3S) 2.44 ± 0.07 ± ± ± ± 3.5 Few % precision reached! B µµ (ϒ(2,3S)) significantly higher than prior results Await CLEO Γ ee! 27 June 2004 Richard S. Galik 14

15 QQ to Q Q : ϒ(1S) (cc) X onia production and onia decay test of color-octet v. color-singlet models similar rate predictions very different momenta spectra may have some relevance to cccc production ϒ J/ψ color-octet [ Chueng, Keung, Yuan: PRD 54, 929 (1996) ] ϒ color-singlet [ Li, Xie, Wang: PLB 482, 65 (2000) ] c c J/ψ 27 June 2004 Richard S. Galik 15

16 ϒ(1S) J/ψ X p/p max much too soft for octet model ϒ CLEO Preliminary CO B(ϒ(1S) J/ψ X) = (6.4 ± 0.4 ± 0.6) x 10-4 CS This includes feed-down from other charmonia Rate consistent with either octet or singlet model Production and helicity angular distributions also determined Scaled Momentum (p/p max ) (ggg component only!) 27 June 2004 Richard S. Galik 16

17 ϒ(1S) (cc) X Also see first observation of ψ X B(ϒ ψ X)/B(ϒ J/ψ X) = (41± 11± 8)% and evidence for the two χ c states with large Γ E1 B(ϒ χ c2 X)/B(ϒ J/ψ X) = (52 ± 12± 9)% B(ϒ χ c1 X)/B(ϒ J/ψ X) = (35 ± 8± 6)% all larger than the octet predictions. 27 June 2004 Richard S. Galik 17

18 14% Rule or ρπ Puzzle Decay through cc annihilation and production via e + e - both depend on Ψ(0) 2 therefore naively expect J/ψ 3.1GeV ψ(2s) 3.7GeV ~ 12 % Complications, considerations, caveats running of α s helicity issues interference FF dependence on s NR effects etc. so compliance within factor of two is probably agreement. Biggest offenders: πρ and K*K both PV limits on Q h /Q ee < 0.1 Big data sets of BES and CLEO to the rescue!! 27 June 2004 Richard S. Galik 18

19 ψ (3686) K*K [ BES preliminary ] 14M ψ events 6.4 pb -1 continuum Use K S K ± π final state ± K * 2 (1430) K *0 K* ± K *0 K* 0 K ±9.0 events, ~11σ B(ψ K* 0 K 0 ) = (15.0±2.1±1.7) 10 5 Q h = (3.6 ± 0.7) % K* ± K * 2 (1430) K* + K - 9.6±4.2 events, ~3.5σ B(ψ K* + K - ) = (2.9±1.3±0.4) 10 5 Q h = (0.6 ± 0.3) % [suppressed!] Results have no continuum subtracted (need more!) Also have events for ωπ 0 27 June

20 (Continuum) ψ (3686) ρπ [ CLEO preliminary ] ~3M ψ events (5.5 pb -1 ) ~20 pb -1 continuum Use π + π π 0 final state ψ and continuum both show ρ signal! ρ Scaled Continuum Large continuum sample allows for subtraction Dalitz plot for J/ψ very empty in center!! [BES: hep-ex/ ] J/ψ π + π - π 0 27 June 2004 Richard S. Galik 20

21 ψ (3686) ρπ, π + π π 0, [CLEO Preliminary] Results based on E vis / s ρπ: 4.2σ, Q h /Q ee = 0.016±0.006 Equal signals in both modes π π + π 0 : >6σ, Q h /Q ee = 0.053±0.011 Also see >3σ signals in ωπ 0 (V), ρ 0 η (V), K* 0 K 0, and b 1 π (AP). All have continuum subtraction, but assume no interference. 27 June 2004 Richard S. Galik 21

22 Status of Puzzle ρπ and K*K measured!!! K* + K - much more suppressed than K* 0 K 0 ; -spin violation large -spin violating states obey 12% Rule AP states not suppressed VT states at about 1/5 Do the suppressed states show up in the ψ(3770)?! Q h /Q ee 27 June 2004 Richard S. Galik 22

23 Status of Puzzle ρπ and K*K measured!!! K* + K - much more suppressed than K* 0 K 0 ; -spin violation large -spin violating states obey 12% Rule AP states not suppressed VT states at about 1/5 Do the suppressed states show up in the ψ(3770)?! Q h /Q ee 27 June 2004 Richard S. Galik 23

24 Status of Puzzle ρπ and K*K measured!!! K* + K - much more suppressed than K* 0 K 0 ; -spin violation large -spin violating states obey 12% Rule AP states not suppressed VT states at about 1/5 Do the suppressed states show up in the ψ(3770)?! Q h /Q ee 27 June 2004 Richard S. Galik 24

25 Status of Puzzle ρπ and K*K measured!!! -spin violating states obey 12% Rule K* + K - much more suppressed than K* 0 K 0 ; -spin violation large AP states not suppressed VT states at about 1/5 Do the suppressed states show up in the ψ(3770)?! Q h /Q ee 27 June 2004 Richard S. Galik 25

26 ψ and J/ψ Decays to Two Pseudo-scalars A B φ AB Three-gluon K 0 K 0 and K + K - Electro-magnetic π + π - and K + K - Not π + π - (G-parity) K + K - π + π - Not K 0 K 0 (SU(3)) K 0 K 0 φ AB φ AB known for J/ψ (90±10) BES now determines φ AB for ψ 27 June 2004 Richard S. Galik 26

27 BES - 14 million ψ π + π - and K + K - inputs B(ψ K S K L ) = (5.24 ± 0.47 ± 0.48) x 10-5 φ AB (ψ )= -(82 ± 29) or (121 ± 27) consistent with φ AB (J/ψ) Also (re)measure B(J/ψ K S K L ) = (1.82 ± 0.04 ± 0.13) x 10-4 so B(ψ K S K L ) / B(J/ψ K S K L ) = (29±4)% (12% rule viol?) [ PRL 92, (2004), PLB567, 73(2003), PRD69, (2004) ] 27 June 2004 Richard S. Galik 27

28 QQ States with L=2 ( D ) Charmonium Bottomonium ψ(3770): 3 S 1-3 D 1 mixing? Molecule? ϒ(1D): stable - tests models and LQCD at high L!! 27 June 2004 Richard S. Galik 28

29 Final ϒ(1D) Analysis Results [CLEO] Four γ cascade; exclusive ϒ(1S) channel Background thru 2 3 S 1 First reported CHEP 02 with 80% of data now final Accepted by PRD [hep-ex/ ] 27 June 2004 Richard S. Galik 29

30 Final ϒ(1D) Analysis Results [CLEO] >10 σ significance M = ±0.6±1.6 MeV Mass recoiling against γ 1 γ 2 Consistent with 1 3 D 2 B (ϒ(3S) γ 1 γ 2 γ 3 γ 4 l l ) = (2.5 ± 0.5 ± 0.5) x 10-5 Mass from χ 2 minimization Rate consistent with theory estimates [hep-ex/ ; accepted by PRD] 27 June 2004 Richard S. Galik 30

31 D State mpact on LQCD Ratio = LQCD/Expt ϒ Spectrum Quenched Unquenched (n f =3) [CTH Davies et al., PRL 92: (2004) ] Quenched m u = m d = m s /5 [ Courtesy: G.P. Lepage ] 27 June 2004 Richard S. Galik 31

32 ϒ(1D): What is NOT seen!!! Search for ϒ(1D) π + π - ϒ(1S) ϒ(2S) Large signal from ϒ(2S) consistent with known rates ϒ(1D) No events observed from ϒ(1D); upper limits set [hep-ex/ ] Limits ~7 times lower than predicted by Kuang-Yan model; ~3 times higher than Ko model [ J.L.Rosner PRD67, (2003) ] Also see no evidence for enhancement of ϒ(1D) ηϒ(1s) as postulated by Voloshin [PL B562, 68 (2003)] 27 June 2004 Richard S. Galik 32

33 More on Nature of ψ(3770) Belle [hep-ex/ ] Solid signal seen by Belle in B + K + D 0 D 0 98±18 evts DD mass fit yields B(B K + ψ(3770)) = (4.8±1.1±0.7) x 10-4 ~2/3 of B(B K + ψ(2s)) Large 3 S 1-3 D 1 mixing? Color-octet models predict B(B ψ(3770) X) at few 10-3 ΔE (GeV) 27 June 2004 Richard S. Galik 33

34 ψ(3770) : Learning from Decays to J/ψ ππ ψ(3770) = α 3 S 1 + β 3 D 1 + γ DD + ψ(3770) does couple to e + e - Γ ee = 0.26 kev ψ(3770) π + π - J/ψ [J. L. Rosner hep-ph/ ] Mark and BES: Γ(π + π - J/ψ ) = (43 ± 14) kev CLEO 90% limit at this level too New BES result larger data sample in preparation Kuong-Yan predict kev (depending on mixing) CLEO limit in ϒ(1D) x7 below K-Y prediction Angular distribution for π + π - J/ψ could sort out α, β, γ Very large CLEO data sample upcoming!! [Voloshin - priv comm] 27 June 2004 Richard S. Galik 34

35 QQ States with L=1 ( χ ) Charmonium Bottomonium Produced copiously by E1 decays of vector parents; also produced in γγ fusion and in hadron colliders Very little tabulated about decays 27 June 2004 Richard S. Galik 35

36 Observation of χ b (2P) ωϒ (1S) New ϒ hadronic transition - not ππ! First hadronic transition for χ b states! ω µµ,ee Starts with E1 γ from ϒ(3S); ends with ϒ(1S) to lepton pairs Preliminary results last summer; now final, with full ϒ(3S) data sample 27 June 2004 Richard S. Galik 36

χ b (2P) ωϒ (1S) Final Results: +0.35 +0.16-0.31-0.15 B(χ b1 ωϒ(1s))= (1.63 )% +0.32 +0.11-0.28-0.10 B(χ b2 ωϒ(1s))= (1.10 )% J = 0 kinematically forbidden!

37 χ b (2P) ωϒ (1S) Final Results: B(χ b1 ωϒ(1s))= (1.63 )% B(χ b2 ωϒ(1s))= (1.10 )% J = 0 kinematically forbidden! CLEO m(π + π - π 0 ) Roughly equal for J = 1 and 2 r 2/1 predicted to be 1.3 ± 0.3 [Voloshin - hep-ph/ ] MC ϒ γχ b2 MC ϒ γχ b1 Very large rate considering limited phase space! E γ [hep-ex/ , accepted by PRL] 27 June 2004 Richard S. Galik 37

38 Testing Color Octet Model with χ c Decays Predictions exist for cc decays to baryon-antibaryon contain color octet contributions color singlet alone cannot account for rate of cc pp indicate suppression of ΛΛ with respect to pp define R B = Γ(ΛΛ)/Γ(pp) R B = 0.60 for J=1 and 0.45 for J=2 Singlet Graph Octet Graph S. M. Wong, Eur. Phys. J. C14, 643 (2000) 27 June 2004 Richard S. Galik 38

39 BES - ΛΛ BES - pp PRD67, (2003) PRD69, (2004) χ c0 χ c0 χ c1 χ c2 χ c1 χ c2 Nice signals in pp - branching fractions consistent with PDG and same accuracy; weaker signals in ΛΛ first measurements. J = 1: R b = 4.6 ± 2.3 J = 2: R b = 5.1 ± 3.1 Large uncertainties, but show ΛΛ enhanced, not suppressed! 27 June 2004 Richard S. Galik 39

40 X(3872) - Just what S it??? cc? Molecule? Four clear sightings two in B + K + X(3872) originally by Belle (>10σ) [ PRL 91, (2003) ] Αll J/ψ π π K M bc (GeV) M(J/ψ ππ) (GeV) ΔE (GeV) X(3872) region and recently by BaBar. [ hep-ex/ ; subm d to PRL ] M bc (GeV) 27 June 2004 Richard S. Galik 40

41 m ππ in X J/ψ π + π Belle Both Belle/BaBar see similar m ππ structure; this is used by CDF/D0 to clean up background (next slide). m ππ (GeV) s there a ρ component (C X =+)? Or is the high-mass region a copy of ψ(3686) decay? s there really a second low-m ππ peak similar to that observed in ϒ(3S) ϒ(1S) π π? No measures or limits (yet!) for X J/ψ π 0 π 0!! Would establish C X = -1. BaBar m ππ (GeV) 27 June 2004 Richard S. Galik 41

42 More sightings of X!! Two clear observations in hadron production hep-ex/ ; sum d to PRL. first CDF (QWG) All m(ππ) and then recently D σ m(ππ) > 500 MeV pretty convincing! 27 June 2004 Richard S. Galik 42

43 Mass (GeV/c 2 ): Basic X(3872) Parameters Belle: ± 0.6 ± 0.5 CDF: ± 0.7 ± 0.4 D0: ± 3.1 ± 3.0 BaBar: ± 1.4 Width (Γ) (MeV/c 2 ): My average: M(X) = ± 0.5 [ M(D 0 D 0 *) = ± 0.7 M(D - D + *) = ± 1.0 ] Belle: < 2.3 (90% CL) CDF: consistent with resolution (5) D0: consistent with resolution (17) NARROW! BaBar: smaller than resolution (~3) 27 June 2004 Richard S. Galik 43

44 hep-ex/ ; subm d to PRL X Production and Decay Characteristics (see also H. Evans talk) Production fractions: a: p T > 15 GeV/c (transv mom) b: y < 1 (rapidity) e: isolated from rest of event Decay fractions: c: cos θ π < 0.4 (pion helicity) d: dl < 1mm (effec decay length) f: cos θ µ < 0.4 (muon helicity) Similar studies underway at CDF. 27 June 2004 Richard S. Galik 44

45 More comparisons to ψ [BaBar and Belle combined] or ± (1.37 ± 0.25) x 10-5 Perhaps X(3872) = α (D 0 D 0 * + C.C.) + β (cc) β 2 a few percent (?) α large (coincidence that M X = M D0 + M D0*?) J PC = 1 ++? (too narrow to have natural parity?) minimal D + D - * component (so much for isospin!) several other searches bear on J PC [Thanks to M.V., J.R., T.Skwarnicki] 27 June 2004 Richard S. Galik 45

More Attempts to Determine Nature of X(3872) Belle: PRL 91, 262001( 03);

hep-ex/0307061 { ~4x that for J/ψππ expected for such a molecule?

46 More Attempts to Determine Nature of X(3872) Belle: PRL 91, ( 03); hep-ex/ not likely 3 D 2 not likely 3 D 3 not likely χ c (2 3 P J ) Belle: hep-ex/ { ~4x that for J/ψππ expected for such a molecule? [hep-ph/ ] [CLEO Prelim.] } not likely 1 -- [CLEO Prelim.] not likely 0 ±+, 2 ±+ 27 June 2004 Richard S. Galik 46

47 Summary (of sorts) New data, finished analyses, and renewed interest!! D State (L=2) established in ϒ system; agrees with LQCD η c firmly established! Δh f = 49 MeV to ~ 5% ; LQCD gives? Several analyses confronting the color octet model PV states finally observed in ψ decay Q h /Q ee ~ 1/50 Nature of ψ(3770) still a puzzle more data coming SOON! Very narrow X(3872) firmly established; many tests of J PC done inconclusive; cc? DD* molecule? nterested join QWG! Thanks to all from BES, BaBar, Belle, CDF, CLEO and D0 27 June 2004 Richard S. Galik 47

CLEO Results on Quarkonium Transitions

CLEO Results on Quarkonium Transitions Brian Heltsley Cornell University QWG3 B Heltsley Oct 2004 1 Quarkonia Transitions ψ(2s) J/ψ + hadrons (NEW!) X J/ψ, π + π - J/ψ, π 0 π 0 J/ψ, η J/ψ, π 0 J/ψ (complete