CLEO Results on Quarkonium Transitions

Transcription

1 CLEO Results on Quarkonium Transitions Brian Heltsley Cornell University QWG3 B Heltsley Oct

2 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 set) Radiative transitions in charmonium & bottomonium n 3 S 1 γ (n-1) 3 P J (χ J ) n 3 P J γ (n,n-1) 3 S 1 n 3 S 1 γ (n-1,n-2) 1 S 0 (η Q ) 1 st Observation of ϒ(1 3 D 2 ) (Review) ϒ(1 3 D 2 ) π + π - ϒ(1S)? QWG3 B Heltsley Oct

3 ψ(2s) XJ/ψ ψ(2s) decays: Transitions: J/ψ π + π - J/ψ π 0 π 0 J/ψ η Σ excl J/ψ π 0 Radiative Decays: γχ cj (E1) γη c (M1) γη c (M1) Annhilation: Dileptons direct decay light hadrons BRs for XJ/ψ, π + π - J/ψ serve as normalizing modes Many relative msmts, few absolute PDG fit takes input from different expmts & eras A 1 st : precision, totality of channels, internal ratios w/ correlations handled Questions: π 0 π 0 J/ψ : π + π - J/ψ? B(ψ(2S) light hadrons)? XJ/ψ Σ excl? ( Σγχ cj γγj/ψ) QWG3 B Heltsley Oct

4 Strategy Fully reconstruct J/ψ ee,µµ Use E/p only as ID η γγ & π + π - π 0 Loose selection to minimize systematics Small bgd, mostly cross-feed among themselves Trigger eff>98.6% #ψ(2s): ±3% Robust against cut variation: ε=~50-85% Add bremsstrahlung γ s to lepton momenta within 100mr cone ee/µµ = 1? ψ(2s): 3.08M decays Continuum: ~20 pb -1 GeV QWG3 B Heltsley Oct

5 ψ(2s) X J/ψ, J/ψ l + l - ψ(2s) BW Tail Scaled Continuum Subtract scaled continuum ψ γχ c0, χ c0 KK,ππ ε=69% (µ), 61% (e) (wtd by BR) QWG3 B Heltsley Oct

6 Excellent Data/MC agreement M(l + l - ), M(ππ) M(ππ-recoil) E/p of leptons M(π 0, η γγ, η π + π - π 0 ) cos θ p(j/ψ) p(π ±,π 0 ) at all momenta See supplemental slides QWG3 B Heltsley Oct

7 ψ(2s) ππ J/ψ, J/ψ l + l - MC Data η π + π - π 0 η π 0 π 0 π 0 QWG3 B Heltsley Oct

8 ψ(2s) ππ J/ψ, J/ψ l + l - cosθ µ + cosθ e + cosθ µ + cosθ e + cosθ J/ψ cosθ J/ψ cosθ J/ψ cosθ J/ψ µ + µ - π + π - cosθ π-low cosθ π-low cosθ π-low cosθ π-low cosθ cosθ QWG3 B Heltsley Oct

9 ψ(2s) η J/ψ, η γγ, 3π ψ(2s) γχ c0, χ c0 γj/ψ QWG3 B Heltsley Oct

10 Uncertainties (relative, %) Channel Stat(%) 2 biggest syst (%) Total * (%) π + π - J/ψ (π ± ) 0.5 (dec rad) 5.3 π 0 π 0 J/ψ (π ± ) 2 (π 0 ) η(γγ)j/ψ (π ± ) 1 (π 0, xfeed) η(3π)j/ψ (π ± ) 1.5 (xfeed) π 0 J/ψ (xfeed) 2 (π ± ) XJ/ψ (π ± ) 0.5 (dec rad) π ± (π - )J/ψ trk 0.5 dec rad π 0 (π 0 )J/ψ trk 0.5 dec rad * Total includes #ψ(2s) normalization error of ±3% We assign a sys error of 1% per π ± & add linearly over π ± s per event. Similarly, 1% per π QWG3 B Heltsley Oct

11 CLEO Preliminary: BR in % relerror in % X J/ψ π + π - J/ψ π 0 π 0 J/ψ B B/B XJ/ψ B/B π+π-j/ψ 59.6±0.2± % CLEO Prelim PDG 55±7 12.7% PDG avg, not fit 33.3±0.1± % 55.8±0.3± % 32.3± % 53.5±0.7± % BES 16.9±0.2± % 28.3±0.3± % 50.7±0.5± % 32.7± % 57.0±0.9± % 3.3±0.1± % 5.5±0.1± % 9.9±0.2± % η(γγ) J/ψ 3.0±0.1± % 6.9 ± % 9.8±0.5± % η(3π) J/ψ 3.3±0.1± % 5.5±0.2± % 9.9±0.4± % 0.15±0.02± % 0.26±0.03± % 0.46±0.05± % π 0 J/ψ 0.143±0.013± % PDG PDG QWG3 B Heltsley Oct

12 Further Results B(J/ψ ee)/b(j/ψ µµ)= ± (1.4σ < 1) BES: 1.011±0.021 y CLEO Preliminar B(ψ(2S) light hadrons) = 1 Σexcl Σγχ cj - γη c Σll = 17.2±3.6% CLEO results for all terms except Σll Q(l.h.)=B(ψ(2S) l.h.)/ B(J/ψ l.h.)= 19.8±4.1% Incl-Excl= 6.2±1.1% =? indirect ΣB(ψ(2S) γχ cj ) B(χ cj γ J/ψ) ) 1.5σ>BES (4.5±0.2%), 2σ>PDG(CBAL) (3.9±0.3%) QWG3 B Heltsley Oct

13 Summary: ψ(2s) XJ/ψ NEW, PRELIMINARY CLEO msmts of all J/ψ excl hadronic BRs & incl J/ψ as well Systematics limited, many cross checks performed Most precise, or comparable to previous π 0 π 0 absolute rate msd for 1 st time Full reconstruction of both π 0 s Lower ratios of BR s than BES, E835, E760 π 0 π 0 /π + π - ratio ~1/2 as expected from isospin (Incl-Excl) provides BR cross check 1 st single-experiment test of inclusive 12% rule QWG3 B Heltsley Oct

14 CLEO ϒ & ψ(2s) Data Resonance Lumi (pb -1 ) CLEO III # decays (10 6 ) CLEO II Crystal Ball (CUSB) Number of resonance decays (10 6 ) ϒ(1S) ϒ(3S) 1460 ϒ(2S) 1380 ϒ(1S) ψ(2s) st half of total CLEO sample (1.3) [ ψ(2s) BES-II 14.0 ] ϒ(3S) ϒ(2S) ψ(2s) Series1 Series2 Series3 CLEO III CLEO II CB or CUSB >10-fold increase for the narrow ϒ resonances 1st experiment to match Crystal Ball sensitivity for photon transitions from ψ(2s) QWG3 B Heltsley Oct

15 ψ(2s) Inclusive γ Spectrum η c? charmonium η c QWG3 B Heltsley Oct

16 η c (1S) & η c (2S) BR(ψ(2S) γη c (2S)) CLEO-c % CL U.L. C.Ball % CL interval ψ(2s) γ η c (1S) 8.1s significant η c (1S) Bkg. subtracted QWG3 B Heltsley Oct

17 ψ(2s) E1 & M1 transitions B(ψ(2S) γx) in % E1 Lines: Branching Ratios Hindered M1 Line J=2 J=1 J=0 J=0 CLEO 9.33±0.14± ±0.11± ±0.11± ±0.04±0.06±0.03 C.Ball 8.0±0.5± ±0.5± ±0.5± ±0.06 PDG 7.8± ± ± ±0.06 ratio 1.20± ± ± ±0.38 Eγ in MeV E1 Lines: Photon energies J=2 J=1 J=0 Hindered M1 Line J=0 CLEO ±0.13± ±0.19± ±0.37±1.31 PDG ± ± ±0.38 Ratio ±0.0014± ±0.0013± ±0.0020± ±2.6± ± ±0.009 Good agreement on branching ratios, ~smallest errors Hindered M1 transition confirmed! Use results to recalibrate calorimeter energy scale for ϒ s QWG3 B Heltsley Oct

18 Bottomonium transitions 2 sets of lines to P states QWG3 B Heltsley Oct

19 ϒ(nS) γχ b ϒ(2S) χ b (1P J ) γ ϒ(3S) χ b (2P J ) γ BKG=ϒ(1S) + continuum + 0 th order polynomial BKG=ϒ(1S) + continuu + 1st order polynomial ϒ(1D J ) χ b (1P j ) γ ϒ(2S) χ b (1P J ) γ QWG3 B Heltsley Oct

20 ϒ(3S) χ bj (1P J ) γ We were able to extract BR(ϒ(3S) χ b (1P 0 ) γ) whose peak is isolated BKG=3 rd order polynomial ϒ(3S) χ b (1P 2 ) γ + ϒ(3S) χ b (1P 1 ) γ + χ b (1P J ) ϒ(1S) γ ϒ(3S) χ b (1P 0 ) γ No significant enhancement around E~350MeV which would correspond to ϒ(3S) η b (2S) γ QWG3 B Heltsley Oct

21 ϒ(2S) χ b2 γ E γ BR Significantly improved errors (systematics dominated) Excellent agreement between CLEO3 and previous msts of photon energies and branching ratios See supplemental slides for complete set of plots like this; also tables w/#s QWG3 B Heltsley Oct

22 χ b, χ b Masses ϒ State Mass (MeV) 2S ±0.31 3S ± 0.5 2P ±0.06±0.57 2P ±0.07±0.56 2P ±0.16±0.68 1P ±0.08±0.43 1P ±0.09±0.43 1P ±0.19±0.53 PDG input CLEO ONLY CLEO ONLY QWG3 B Heltsley Oct

23 Electric Dipole Transitions ΓE 1 ( nis n f P) = α eq (2J + 1) Eγ n f P r nis 27 E1 matrix element is spin independent in NR limit Below, ratio of Γ E1 s normalized to (2J+1)E γ3. Also results from ψ χ cj γ analysis are shown. 2 (J=2)/(J=1) χ b (2P): (J=0)/(J=1) (J=0)/(J=2) (J=2)/(J=1) χ b (1P): (J=0)/(J=1) (J=0)/(J=2) (J=2)/(J=1) χ c (1P): (J=0)/(J=1) (J=0)/(J=2) 1.00±0.01± ±0.02± ±0.02± ±0.02± ±0.02± ±0.02± ±0.02± ±0.01± ±0.01±0.05 In bb, (J=2)/(J=1) ~ 1 consistent with NR expectation. In cc, (J=2)/(J=1) > 1 due to smaller quark mass. Transitions to J=0 indicate relativistic effect at ~20% even for bb. QWG3 B Heltsley Oct

24 ϒ(3S) η b (1S) γ & ϒ(2S) η b (1S) γ More data since ICHEP 02 E1 E1 E1 1 3 P J γ1 3 S 1 M1 2 3 P J γ1 3 S 1 M1 2 3 S 1 γ1 1 S S 1 aγ1 1 S 0 Hindered M1 π 0 background ϒ(2S) data π 0 background ϒ(3S) data γ γ E1 Hadrons ( π 0..) γ γ QWG3 B Heltsley Oct

25 Test potential models Γ M1 Models from the compilation by Godfrey&Rosner PR D64, (2001); Ebert,Faustov, and Galkin, PRD67, (2003); Lahde NP A714, 183(2003) [scaled here by phase-space] Limits are best here at high E where lower bgd Data rule out many predictions! QWG3 B Heltsley Oct

26 Test potential models Γ M1 QWG3 B Heltsley Oct

27 1 st Observation of ϒ(1 3 D 2 ) PRD70, (2004) γ γ γγ Recoil mass γ Four successive E1 transitions γ M(ϒ(1 3 D 2 ))= ±0.6±1.6 MeV e - γ γ e + e -,µ + µ e + γ γ γ µ + µ γ B(ϒ(3S) γγϒ(1d) γγγγ ϒ(1S) γγγγ l + l - ). =(2.6±0.5±0.5) 10-5 γ γ Godfrey&Rosner PRD64,097501(2001) 1st new long-lived heavy quarkonium state in 20 yrs QWG3 B Heltsley Oct

28 Potential models: M(ϒ(1D))=? Models which have success with other ϒ masses success w/mass of ϒ(1 3 D 2 ) Fits to quarkonia masses possible with as few free parameters as one (accuracy ~0.2% of mass, 2% of excitation energy) - perhaps the most convincing proof for quark structure of hadrons Several potential models consistent w/data QWG3 B Heltsley Oct

29 Beyond potential models Advances in lattice QCD calculations: Old (quenched) New G.P. Lepage, High Precision Nonperturbative QCD at the SLAC Summer Institute (August 2002; Update May 2003) QWG3 B Heltsley Oct

30 ϒ(1 3 D 2 ) π + π - ϒ(1S)?? γ γ γ Could X(3872) be a 1D state? Let s see how a D state in the ϒ system behaves. π + π π + π ϒ(3S) γγπ + π - ϒ(1S), ϒ(1S) l + l - is our calibration signal e + e -, µ + µ - QWG3 B Heltsley Oct

31 ϒ(1 3 D 2 ) π + π - ϒ(1S)? No. Limit on product BRs B(ϒ(3S) γγϒ(1d 2 )) B(ϒ(1D 2 ) π + π - ϒ(1S)), units of CLEO Kuang- 90% CL Yan Moxhay Ko ϒ(1D 2 ) < ϒ(1D J ) < With Rosner s production rates Kuang-Yan predictions ruled out ηϒ(1s) also ruled out at QWG3 B Heltsley Oct

32 Conclusions CLEO has new, preliminary results on transitions to a J/ψ w/1 or more hadrons Complete set, improved precision CLEO has final results (E γ, BR) on radiative transitions from the ψ(2s) & ϒ(nS) system η b s not yet seen, some potential models ruled out η c confirmed Old η c from CBAL ruled out At current known η c mass, γ too soft, broad for CLEO Relativistic effects seen for BOTH cc & bb ϒ(1 3 D 2 ) seen ϒ(1 3 D 2 ) observed in photon transitions from ϒ(3S), not in π + π - ϒ(1S) QWG3 B Heltsley Oct

33 Supplemental Slides QWG3 B Heltsley Oct

34 ψ(2s) ππ J/ψ, J/ψ l + l - π π QWG3 B Heltsley Oct

35 ψ(2s) η J/ψ cosθ µ + cosθ e + cosθ µ + cosθ e + cosθ J/ψ cosθ J/ψ cosθ J/ψ cosθ J/ψ cosθ cosθ QWG3 B Heltsley Oct

36 ψ(2s) π 0 J/ψ, π 0 γγ cosθ µ + cosθ e + cosθ J/ψ µµπ 0 cosθ J/ψ cosθ QWG3 B Heltsley Oct

37 Decay Radiation Model with PHOTOS Also search for explicit radiation as below Reasonable but not perfect agreement Assign 0.5% error, separately for e, µ Looking for extra γ µµγ eeγ QWG3 B Heltsley Oct

38 γ Transitions: Detector Excellent charged particle detection EM calorimeter- Essential for γ spectrocopy ~8000 CsI(Tl) crystals + photo-diodes First crystal calorimeter in magnetic field COIL (1-1.5T) Detector Calorimeter crystals σ Eγ resolution at Eγ=100 MeV CLEO-III CsI(Tl) 4.5 MeV CUSB-II BGO 4.2 MeV Crystal Ball NaI(Tl) 4.8 MeV BES-II Not a crystal calorimeter 70 MeV QWG3 B Heltsley Oct

39 ψ(2s) Photon Spectrum? Crystal Ball CLEO-c New η c mass More data, comparable resolution With maximal suppression of the π 0 background for comparison with C.Ball only (harmful at low photon energies) QWG3 B Heltsley Oct

40 ϒ χ b1 γ E γ BR QWG3 B Heltsley Oct

41 ϒ χ b0 γ E γ BR QWG3 B Heltsley Oct

42 ϒ χ b2 γ E γ BR QWG3 B Heltsley Oct

43 ϒ χ b1 γ E γ BR QWG3 B Heltsley Oct

44 ϒ χ b0 γ E γ BR QWG3 B Heltsley Oct

45 Tables of Results This msmt CLEO2 (1998) PDG BR(ϒ χ b0 γ) BR(ϒ χ b1 γ) BR(ϒ χ b2 γ) E γ (ϒ χ b0 γ) E γ (ϒ χ b1 γ) E γ (ϒ χ b2 γ) 3.75±0.12±0.47% 3.4±0.5±0.6 % 3.8±0.6 % 6.93±0.12±0.41% 6.9±0.5±0.9 % 6.8±0.7 % 7.24±0.11±0.40% 7.4±0.5±0.8 % 7.0±0.6 % ±0.19±0.42MeV 162.0±0.8±1.2 MeV 162.1±1.0 MeV ±0.09±0.29MeV 128.8±0.4±0.6 MeV 129.8±0.5 MeV ±0.08±0.30MeV 110.8±0.3±0.6 MeV 110.1±0.5 MeV This msmt CLEO2 (1991) PDG BR(ϒ χ b0 γ) BR(ϒ χ b1 γ) 6.77±0.20±0.65% ±0.6 % 5.4±0.6 % 14.54±0.18±0.73% ±1.3 % 11.3±0.6 % BR(ϒ χ b2 γ) 15.79±0.17±0.73% 13.5±0.3±1.7 % 11.4±0.8 % BR(ϒ χ b0 γ) 0.30±0.04±0.10% - - E γ (ϒ χ b0 γ) ±0.16±0.46MeV 122.3±0.3±0.6 MeV 122.8±0.5 MeV E γ (ϒ χ b1 γ) 99.15±0.07±0.25MeV 99.5±0.1±0.5 MeV 99.90±0.26 MeV E γ (ϒ χ b2 γ) 86.04±0.06±0.27MeV 86.4±0.1±0.4 MeV 86.64±0.23 MeV QWG3 B Heltsley Oct

46 χ b Systematic Errors QWG3 B Heltsley Oct

47 χ b Systematic Errors QWG3 B Heltsley Oct

48 Electric Dipole Transitions II Γ E1 ( nis n f P) = α eq (2J + 1) Eγ n f P r nis Extract the above E1 matrix element by Γ E1 =BR(n f S n f P) Γ total (ϒ(nS)) for each J s and using the latest CLEO measurements of Γ total (ϒ(2S)) and Γ total (ϒ(3S)). Matrix elements averaged over spins are shown below along with various predictions. Also result from ψ χ cj γ analysis is shown using Γ total (ψ(2s))=277±22kev (PDG) 2 cc Exp value YEAR bb o = predictions (non-relativistic) = predictions (relativistic) (averaged over spins) cc system is calling for relativistic corrections. The correction is small in bottomonium. In bb system, non-relativistic calculations seem to reproduce the measured rates. QWG3 B Heltsley Oct