Quarkonium spectroscopy and new states from BaBar Lorenzo Vitale Università and INFN Trieste, ITALY on behalf of BaBar Coll. DIS06, Apr 20-25, 2006 Lorenzo Vitale

PEPII & BaBar: not only B physics SVT: 97% efficiency – 20mm z resol SVT+DCH: s(pt)/pt=0.13%·pt+0.45% EMC: s(E)/E=2.32%·E-1/4+1.85% Asymmetric energy B-Factory & Detector were optimized for CP in B physics … Excellent tracking and vertexing Excellent particle identification Excellent γ, π0 detection Data: ~330 fb-1 recorded so far ~90% @ 10.58 GeV ϒ(4S) ~360 M BB pairs ~10% @ 10.54 GeV qq … but plenty of other topics can be investigated THIS TALK: QUARKONIUM 1m DIS06, Apr 20-25, 2006 Lorenzo Vitale

T.Barnes, S.Godfrey and E.S.Swanson Heavy Quarkonia Spectra Rich spectroscopy. Predictions become more critical when states are above the threshold for open flavour production Bottomonium Charmonium Y(4260)? S/P? ϒ(4S) X(3872)? T.Barnes, S.Godfrey and E.S.Swanson Phys.Rev. D72 054026 (2005) DIS06, Apr 20-25, 2006 Lorenzo Vitale

Selected quarkonium topics in this talk: Bottomonium results: hadronic non-BB decays of ϒ(4S) Charmonium results: Results on new particles in B decays and ISR events: X(3872) Y(4260) DIS06, Apr 20-25, 2006 Lorenzo Vitale

Bottomonium Studies: hadronic non-BB decays of ϒ(4S) DIS06, Apr 20-25, 2006 Lorenzo Vitale

Hadronic non-BB decays of ϒ(4S) ϒ(4S)BB mostly, but not only. BF of O(10-4) are expected. Cleo reported only upper limits of that order. LP-05: Belle reports first evidence for ϒ(4S) +- ϒ(1S) B=(1.0±0.2±0.4)•10-4 with 386•106 (4S) hep-ex/0512034, still preliminary We have predictions for partial widths and dipion spectrum in ϒ(mS) +- ϒ(nS), mS nS QCD multipole expansion (Kuan-Yan, PRD24(1981),2874 and many others) But model fails to describe dipion spectrum at low mass in 3S  1S No clear explanation yet (Mixing and coupled channel effects are not accounted for in those models) DIS06, Apr 20-25, 2006 Lorenzo Vitale

BaBar: ϒ(4S) +- ϒ(nS) BaBar Analysis strategy search for ϒ(4S) +- ϒ(nS) with ϒ(nS)  l+l- Results on l+l-=+-, use e+e- as cross check (Bhabha bkg) 211fb-1 preliminary DATA 211fb-1 on peak: (230.0±2.5)•106 (4S) decays 22fb-1 ~40MeV below (4S) as a control sample (no (4S) candidates found) Validations with ISR returns to 2S1S & 3SnS The transition 4S->3S is kinematically not allowed The diagonal band is a QED process like a radiative Bhabha or +- gamma followed by photon conversion or ISR 4pi events. DIS06, Apr 20-25, 2006 Lorenzo Vitale

PRELIMINARY Results preliminary preliminary preliminary ϒ(4S)+-ϒ(1S) 10 signal significance BF=(0.90±0.15)·10-4 =1.8±0.4 keV ϒ(4S)+-ϒ(2S) First evidence @7.3 BF=(1.29±0.32)·10-4 =2.7±0.8 keV preliminary Dipion spectra compared with QCD multipole expansion: 4S1S compatible 4S2S incompatible (peak at low M+-) preliminary Significance n-sigma here is in terms of “Gaussian equivalent” number of sigma's n=sqrt(2logdeltaLik) Diagonal band: bhabha bkg Drop in eff. in first bin due to e+e- cut To be submitted to PRL DIS06, Apr 20-25, 2006 Lorenzo Vitale

Results on X(3872) History & Theory NEWS from BaBar: 2 recently published results 1 preliminary result DIS06, Apr 20-25, 2006 Lorenzo Vitale

Brief history: 2003 discovery (cc interpretation?) First observed by Belle in B± → K±(J/ +-) Mass just at D0D0* threshold Narrow (<2.3 MeV at 90%CL) Compatible with J/0 →IC=1+ final state Then confirmed by CDF, D0 and BaBar all in the same decay mode. Belle PRL 91 (2003) 262001 CDF PRL 93 (2004) 072001 D0 PRL 93 (2004) 162002 BaBar PRD 71 (2005) 071103 Width consistent with experimental resolution Remember that final state J/0 has I=1 1 Since ro_0 doesn’t decay in pi_0 pi_0 so it would be interesting to look for pi_0 pi_0 J/psi 2 large total width expected in potential models Ordinary charmonium interpretation in trouble. This width eliminates many possible assignments. This mass value and absence of c1 are in disagreement with potential model expectations for the 13D2 (JPC=2--) charmonium state DIS06, Apr 20-25, 2006 Lorenzo Vitale

Several Possible Interpretations of X(3872): cc, D0D Several Possible Interpretations of X(3872): cc, D0D*0 molecule, diquark-antidiquark, …? Ordinary cc charmonium state T. Barnes and S. Godfrey, PRD 69 (2004) 054008 E.J. Eichten, K. Lane and C. Quigg, PRD 69 (2004) 094019 (aka Cornell potential model) S-wave D0D*0 molecule N.A. Tornqvist, PLB 590 (2004) 209 M.B. Voloshin, PLB 579, 316 C.Y. Wong, PRC 69 (2004) 055202 E. Braaten and M. Kusunoki, PRD 69 (2004) 074005, 71(2005) 074005 E.S. Swanson, PLB 588 (2004) 189 Dominant 1++ (2P) cc component + D0D*0/D0D*0 continuum component C. Meng, Y.J. Gao and K.T. Chao, hep-ph/0506222 M. Suzuki, PRD 72 (2005) (mainly charmonium + channel coupling to DD*) S-wave diquark-antidiquark bound state cucu L. Maiani, F. Piccinini, A.D. Polosa and V. Riquer, PRD 71(2005)014028 Hybrid ccg B.A. Li, PLB 605 (2005) 306 Vector glueball gg + a small mixture of cc K.K. Seth, hep-ph/0411122 S-wave threshold enhancement in D0D*0 scattering D.V. Bugg, PRD 71 (2005) 016006  DIS06, Apr 20-25, 2006 Lorenzo Vitale

Several experimental studies: other decay modes, production mechanism, “partners”, … BaBar PRL 93 (2004) 041801 no signal for X(3872)  J/  BaBar PRD 71 (2005) 031501 no signals for isovector charged partners of X(3872)  rate should be twice, isovector hypothesis ruled out @ 10–4 level  IX=0 large isospin violation in J/ +- decay BaBar PRD 71 (2005) 051501 no evidence in ISR production  JPC=1-- excluded Cleo PRL 94 (2005) 032004 no evidence in  fusion and rad. production  JPC0-+, 0++, 2++ Belle Preliminary Moriond QCD 06 (also LP05) ~5 evidence of B K D0D*0 (2++ is not favored) Belle hep-ex/0505037 hep-ex/0505038 ~4 evidence of X(3872)J/ and X(3872)J/ sub- threshold  both suggest C=+1  JPC=1++ favored from angular analysis (against 0++, 0-+) isovector hypothesis ruled out @ 10–4 level in terms of ratio of probability to observe the expected signal divided null hypothesis, while BF(B0->K+X-)<5.4 10–6 DIS06, Apr 20-25, 2006 Lorenzo Vitale

X(3872) J/ +- with increased statistics in B0 and B+ decays at BaBar B±→X(3872)K± B0→X(3872)Ks PRD 73 (2006) 011101 61.2±15.3 6.1σ 8.3±4.5 2.5σ 211 fb-1 M=3871.3±0.6±0.1 MeV/c2 M=3868.6±1.2±0.2 MeV/c2 R = BF(B0→X(3872)Ks)=0.50±0.30±0.05 ΔM=2.7±1.3±0.2 MeV/c2 BF(B±→X(3872)K±) 0.13<R<1.10 @90%CL The sign of ΔM is not clear in these predictions R & ΔM can be compared with model predictions R: some molecule model predicts R~0.1 (excluded?) ΔM: ~7±2 MeV/c2 in qqqq model Statistics still low DIS06, Apr 20-25, 2006 Lorenzo Vitale

Search for radiative decays of X(3872) Preliminary X(3872)→J/  in B± → K±X signal extraction validated looking at B+c1K+ 260 fb-1 Implies C=+1 Preliminary results: 19.2 ± 5.7 events BF(B+X(3872) K+)(X(3872)J/ ) = (3.4±1.0±0.3) x 10-6 R = BF(X(3872) J/ ) = 0.34±0.14 BF(X(3872) J/+-) C=+1 cf E.S. Swanson, PLB 598 (2004) 197 Confirms 4σ Belle signal with consistent BF & R hep-ex/050537 (2005) DIS06, Apr 20-25, 2006 Lorenzo Vitale

Inclusive Search for B±K±X(3872) PRL 96 (2006) 052002 Novel technique variant of recoil technique:  one B is fully reconstructed charged K momentum distribution in the recoil rest frame system shows peaks due to two body decays • Observation of X states independent of the decay mode  Allows absolute BF measurement • Huge bkg due to K in recoil B decays e.g. B→ K  J/ No signal: BF(B→XK)< 3.2 10-4 @90%CL BF(XJ/ +-)> 0.042 @90%CL 211fb-1 The lower limit set on BF(XJ/ +-) is sensitive to the distribution of charm quark inside the X(3872) so it can help in understanding the nature of this state Observed signals are consistent with exclusive measurements DIS06, Apr 20-25, 2006 Lorenzo Vitale

Y(4260) DIS06, Apr 20-25, 2006 Lorenzo Vitale Another charmonium related state has been observed by BaBar DIS06, Apr 20-25, 2006 Lorenzo Vitale

BaBar Observation of Y(4260) in ISR Discovered last year in ISR events JPC=1--: e+e-ISR+-J/ J/+-, e+e- PRL 95 (2005) 142001 (2S) 233 fb-1 Y(4260) 12523 events 8  Significance Confirmed by CLEO in energy scan (also in 00J/ mode) hep-ex/0602034 In this analysis the photon may go undetected and actually is reconstructed (24+-8)% in agreement with 25% for the psi(2S) Peak xsec (51 pm 12) pb this number is written only in ISR ppbar paper (PRD 73 (2005) though is from this analysis (here the paper says only around 50 pb) from J/ sideband DIS06, Apr 20-25, 2006 Lorenzo Vitale

Y(4260):Hadronic/dimuon cross section Y(4260) is not observed in the total e+e-hadrons cross section (a dip!), indicating that (Ye+e-) is much smaller than corresponding partial width of all known JPC=1-- charmonium resonances, while (Y+-J/) is much larger. Y(4260) R From this we infer that (e+e-Y)<3x0.6 nb  (Ye+e-)<200 eV and (Y+-J/)>2 MeV Factors >10 and >20 larger than J/+- partial width of (2S) and (3770), resp. √s (GeV) Also here there are several interpretations alternative to conventional charmonium. It is important to search for the Y(4260) in other decay modes …. DIS06, Apr 20-25, 2006 Lorenzo Vitale

No Indication for Y(4260) in Other ISR-produced Final States BABAR: 232 fb-1 PRD 73, 012005 (2006) BABAR: 232 fb-1 To be subm.to PRD BABAR: 289 fb-1 To be subm.to PRL preliminary M(K+K-) Y(4260) Shaded:  sidebands preliminary Shaded: D sidebands (3770) DD(3900) (4040) (4160) (4415) Remember to say that in this way BF(pi+pi-phi)/BF(pipiJ/psi)<0.1at 90%CL that would exclude glueball hypothesis that predicts these to be equal. Remember to say that BF(pipiJ/psi) is large despite this state is above D*D* threshold DIS06, Apr 20-25, 2006 Lorenzo Vitale

Indication of Y(4260) in B decays PRD 73, 011101 (2006) 211 fb-1 3.1σ significance, assuming mass and width from ISR analysis; needs confirmation BF(B±Y(4260) K±, Y(4260) +-J/= (2.0±0.7±0.2) 10-5 DIS06, Apr 20-25, 2006 Lorenzo Vitale

Summary New/First measurements of non-BB hadronic decays of the ϒ(4S)  +- ϒ(nS) Partial widths compatible with expectations Dipion spectrum in 4S2S incompatible with QCD multipole expansion Found several states above the threshold for open flavour production showing unusual properties for an ordinary charmonium state: X(3872) I=0, JPC=1++ narrow state, produced in B decays and observed in several decay modes Y(4260) I=0, JPC=1-- broad state, produced in ISR events (and some indication in B decays), no DD decays seen FURTHER INVESTIGATION IS NEEDED TO UNDERSTAND THE NATURE OF THESE STATES DIS06, Apr 20-25, 2006 Lorenzo Vitale

Backup slides DIS06, Apr 20-25, 2006 Lorenzo Vitale

Known Heavy Quarkonia Spectra Rich spectroscopy with predictions that became more critical when states are close to the threshold for open bottom or charm production DIS06, Apr 20-25, 2006 Lorenzo Vitale

Charmonium production @ B-factories ISR production can give useful complementary information (even no signal) DIS06, Apr 20-25, 2006 Lorenzo Vitale

Mass of X(3872) Mavg = 3871.90.6 MeV/c2 , <2.3 MeV/c2 (90% CL) D0D*0=3871.31.0 MeV/c2 D+D*+=3878.6  1.0 MeV/c2 DIS06, Apr 20-25, 2006 Lorenzo Vitale

no signals for charged partners of X(3872) no signal for X(3872)  J/  no evidence in  fusion and radiative production at CLEO 234M BB PRD 71 (2005) 031501 90M BB PRL 93 (2004) 041801 PRL 94 (2005) 032004 DIS06, Apr 20-25, 2006 Lorenzo Vitale

Evidence for sub-threshold decay X(3872)J/ Evidence of X(3872)J/ Evidence for sub-threshold decay X(3872)J/ hep-ex/0505037 275M BB X(3872) 275M BB M(+-0) (GeV/c2) MJ/ (GeV/c2) 10.63.6 events 4.3  13.6 4.4 events stat. sig.: 4.0  hep-ex/0505037 The evidence of the two decay modes suggests the C parity of X(3872) be +1 DIS06, Apr 20-25, 2006 Lorenzo Vitale

Properties of the X(3872): search for D0D00 decay mode Select B(D0D00)K events An excess M(D0D00) ~ MX is seen N=12.5±3.9 (>5) Rule out 2++ (strong D-wave suppression) Preliminary Br(XDD)/Br(X→ p+p-J/y) =12±5 DIS06, Apr 20-25, 2006 Lorenzo Vitale

BaBar Observation of Y(4260) in ISR ISR events with K+K-J/ spectrum show a featureless mass spectrum  exclude the possibility of K and  misidentification. ISR events with a nJ/ with additional pions show no structure that could feed down to produce Y(4260) in +-J/ mass spectrum. Y(4260) not from two-photon events no substantial improvement obtained by including (4040), (4160) or (4415) in the fits A single relativistic BW (multiplied by PS factor and convoluted with Cauchy resolution function) + 2nd order polynomial are used in the fit. if the observed signal is due to two interfering resonances 1st resonance: M  4260 MeV/c2,   50 MeV 2nd resonance: M  4330 MeV/c2,  narrow Signify the presence of 1-- state containing hidden charm. DIS06, Apr 20-25, 2006 Lorenzo Vitale