html5-img
1 / 90

New BES and CLEO Results Weiguo Li Institute of High Energy Physics,

New BES and CLEO Results Weiguo Li Institute of High Energy Physics, Beijing 100049, P.R. China liwg@ihep.ac.cn ICHEP06, Moscow, July 31, 2006. Outline Introduction Hadron Spectroscopy from J/ Decays (2S) and  CJ Physics D/Ds physics and (3770) Decays Future Plan Summary

anoush
Download Presentation

New BES and CLEO Results Weiguo Li Institute of High Energy Physics,

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. New BES and CLEO Results Weiguo Li Institute of High Energy Physics, Beijing 100049, P.R. China liwg@ihep.ac.cn ICHEP06, Moscow, July 31, 2006

  2. Outline • Introduction • Hadron Spectroscopy from J/ Decays • (2S) and CJ Physics • D/Ds physics and (3770) Decays • Future Plan • Summary Selected topics, thank CLEO and Hanna Mahlke_Kreuger for providing CLEO results

  3. BES and CLEOc are two Recent e+e- Experiments in the Energy Range 2 –5 GeV BESII (1997 - 2004) CLEOc (2003-now) 2-5 GeV R measurements 6+85 energy points (till 2000) Several points in 2004 J/ 5.8107 (2S) 1.4 107 (3770) ~27 pb-1 (2S) 3 106 (3770) 281 pb-1 4170 MeV ~200 pb-1 CLEOc detector has better performances than BESII

  4. Light Hadron Spectroscopy from J/ Decays • Scalars: ,  clearly observed • Possible pp bound state in J/  pp • X(1835) in J/  ’ • The  threshold enhancement in J/   • New observation of a broad 1- - resonance in J/  K+K- 0 Refer to BES talk by Shan Jin

  5. The  pole in at BESII 0 M(+-0)  M()  M(+-)  Averaged pole position: MeV Phys. Lett. B 598 (2004) 149

  6. κ Phys. Lett. B 633 (2006) 681

  7. Phys. Rev. Lett. 91, 022001 (2003) Observation of an anomalous enhancement near the threshold of mass spectrum at BES II J/ygpp BES II acceptance weighted BW +3 +5 -10 -25 M=1859 MeV/c2 G < 30 MeV/c2 (90% CL) c2/dof=56/56 0 0.1 0.2 0.3 3-body phase space M(pp)-2mp (GeV) acceptance

  8. This narrow threshold enhancement is NOT observed in J/pp at BESII • This indicates X(1860) has a production property similar to ’ meson. • This also indicates X(1860) may have strong coupling to gluons as ’ meson. Preliminary J/ pp No narrow strong enhancement near threshold

  9. Not seen in pp experiment • In pp experiments, its expected cross-section is much smaller than continuum process. • In pp elastic scattering, I=1 S-wave dominant, while in J/ radiative decays I=0 S-wave dominant. • Pure FSI disfavored not seen in: B+ K+ pp (BELLE) Y(1S) pp(CLEO)

  10. X(1835) 5.1  X(1835) 6.0  Observation of X(1835) in J/+- Phys. Rev. Lett., 95 (2005) 262001

  11. Combine two channels 7.7 Statistical Significance 7.7  X(1835) Phys. Rev. Lett., 95 (2005) 262001

  12. Re-fit to J/pp including FSI Include FSI curve from A.Sirbirtsev et al. ( Phys.Rev.D71:054010, 2005) in the fit (I=0) M = 1830.6  6.7 MeV  = < 153 MeV @90%C.L. In good agreement with X(1835)

  13. X(1860) and X(1835) might be the same state • masses and widths are consistent. • both connected with ’ meson.  Its spin-parity should be 0-+: this would be an important test. Excited ’ ? Glueball? pp bound state? A mixture of glueball and pp bound state?

  14. Observation of  thresholdenhancement in J/   K+K- +-0   M(K+K-)  Dalitz plot M(+-0) M(K+K-)   M2(g) M(+-0) M2(gw)

  15. A clear threshold enhancement is observed Phase Space Eff. curve Side-bands Side-bands do not have mass threshold enhancement!

  16. The decay of J/ is observed and an enhancement in  is found near the threshold. • PWA shows: the enhancement favors 0++ • Is it the same 0++ observed in KK or , or is it a • glueball, or a hybrid …..? • Further study in , K*K*,  …. desirable ! Phys. Rev. Lett., 96 (2006) 162002

  17. New observation of a broad 1-- resonance in J/  K+K- 0 K*(1410) 0 K*(892) 0 sideband background ? hep-ex/0606047

  18. What is the threshold bump? • JPC should be 1--, 3--, … (Parity conservation) • PWA results • Following components are neededK*(892), K*(1410), (1700), X • 1– is much better than 3— • Pole position of X is • Br • Big destructive interference among X, (1700) and PS Width ~ 800 MeV

  19. More Checks • Replace X by (770), (1900), (2150) with interference among each other, S = 85 not from the interference of known particles • Replace X by (1450) S = 36 ( 8.2)& Br((1450) K+K-) < 1.6  10-3 (95% C.L.)  not (1450) • Further look in to determine its isospin • Search for its K*K, KK decay modes

  20. Property of X(1580) • The width is much broder than other mesons, such as (1450), (1700) Could have different nature from conventional mesons. • The large width is the expectation for a multiquark state(Tetraquark interpretation: M. Karliner, H.J. Lipkin, hep-ph/0607093) hep-ex/0606047

  21. (2S) and CJ Physics Continuum contribution and phase in (2S) decays Branching ratios Phase Interference needs to be considered. Continuum contribution should be subtracted … The interference are neglected in many of the current analyses.

  22. With BESII 14 M (2S) events and 6.4 pb-1 (s=3.65 GeV) and CLEOc 3 M events and 21 pb-1(s=3.67 GeV)12% rule are tested for different modes and the phases between three glue and one photon processes for some modes are measured.

  23. The universal -90°phase? |φ| J/ψ Decays: 1. AP: 90°M. Suzuki, PRD63, 054021 (2001) 2. VP: (106 ±10)°J. Jousset et al., PRD41, 1389 (1990) D. Coffman et al., PRD38, 2695 (1988) N. N. Achasov, talk at Hadron2001 3. PP: (90 ±10)°M. Suzuki, PRD60, 051501 (1999) (103±7)°BES, PRD69, 012003 (2004) 4. VV: (138 ±37)°L. Köpke and N. Wermes, Phys. Rep. 174, 67 (1989) 5. NN: (89 ±15)°R. Baldini et al., PLB444, 111 (1998) ψ(2S) Decays: 1. VP: φ=180°(± 90 ° ruled out!)M. Suzuki, PRD63, 054021 (2001) φ=180° or φ=-90°P. Wang et al., PRD69, 057502 (2004) 2. PP: (-82±29)°or(121±27)° BES, PRL92, 052001 (2004) & Yuan, Wang, Mo, PLB567, 73 (2003) More modes and more (ψ(2S) and continium data are needed

  24. “12% rule”and“ puzzle” M. Appelquist and H. D. Politzer, PRL34, 43 (1975) • Violation found by Mark-II , confirmed by BESI at higher sensitivity. • Extensively studied by BESII/CLEOc • VP mode:  , K*+K-+c.c., K*0K0+c.c., 0,… • PP mode: KSKL, K+K-, +- • BB mode: pp, , … • VT mode: K*K*2, f2’, a2, f2 • 3-body: pp0, pp, +-0, … • Multi-body: KSKShh, +-0 K+K- , 3(+-), …

  25. ’ + - 0 BESII: PLB619, 247 (2005) CLEOc: PRL94, 012005 (2005) 2290s 1960s BESII CLEOc BES and CLEOc in good agreement!

  26. ’ + - 0 Dalitz plots after applying 0 mass cut! Very different from J/3! CLEOc BESII J/ Similar Dalitz plots, different data handling. PWA vs counting! ’ is observed, it is not completely missing, BR is at 10-5 level!

  27. J/, ’ VP BESII : PLB614, 37 (2005); PRD73, 052007 (2006) CLEOc : PRL94, 012005 (2005)

  28. Summary of “12%” rule, Seems no obvious rule to categorize the suppressed, the enhanced, and the normal decay modes of J/ and ’. The models developed for interpreting specific mode may hard to find solution for other (all) modes. • ’ VP suppressed • ’ PP enhanced • ’ VT suppressed • ’ BB obey/enh • Multi-body obey/sup Similarly ’’ decays have a rule of 0.02%, more data and more sophisticated analysis needed to extract the branching fractions from the observed cross sections. Here because the time limitation, I will omit here. • Model to explain J/, ’ and ’’ decays naturally and simultaneously? • S-D mixing in ’ and ’’[J. L. Rosner, PRD64, 094002 (2001)] • DD-bar reannihilation in ’’(J. L. Rosner, hep-ph/0405196) • Four-quark component in ’’[M. Voloshin, PRD71, 114003 (2005)] • Survival cc-bar in ’(P. Artoisenet et al., PLB628, 211 (2005)) • Other model(s)?

  29. cJ production at BESII and CLEO-c CLEO: Phys.Rev. D70 (2004) 112002 • ψ(2S)→cJ, J=0,1,2 - BJ~9%,“cJ factory” - observed in inclusive analysis - B(cJ→hadrons)are not well known c1 c0 c2 • Selected analyses of cJ hadronic decays: • -cJ →η(’)η(’) • -cJ → VV (V = φ, ω) • -cJ → h+h−h0,3-body • decays BES preliminary CLEO preliminary CLEO-CONF-06-9 Refer to BES talk by Ronggang Ping and CLEO talk by Tomasz Skwarnicki

  30. ccJh(’) h(’) cc2 CLEO preliminary cc0 cc1 spin-parity forbiddenResolution 4-8MeVe including intermed BR 4-6% cc1 B(c0) = 0.31 ± 0.05 ± 0.04 % B(c0//) = 0.18 ± 0.04 % ± 0.03 % B(c0/) < 0.05% (90% CL) B(c2) < 0.05% (90% CL) B(c2 //) < 0.03% (90% CL) B(c2/) < 0.023% (90% CL) Comparison with theory: r: DOZI/SOZI • CLEO 2006 preliminaryBES PRD67:032004,2003E835 PRD72:112002, 2005 ▼ ▪ source:Qiang Zhao, PRD72:074001, 2005

  31. BES: cJ→2(K+K) hep-ex/0607025 cJ Pair production of vectors c0 c1 c2 Improved precision over PDG (BESI) results on cJKKKK and . First measurement of cJKK.

  32. Pair production of vectors cJ 38 c0 28 c2 First observation: B(c0) = (2.290.580.41)10-3 B(c2) = (1.770.470.36)10-3 BES: PLB630, 7 (2005)

  33. BES preliminary CLEO preliminary hep-ex/0607072 B (cJ→ h0h+h−) CLEO preliminary (%) 2 Notice: different units 1/2 BES preliminary BES: PRD74, 012004 (2006) BES and CLEO in good agreement!

  34. D, Ds Decay Measurements • Hadronic • Semi-leptonic Form factor • Leptonic fD, fDs mostly from CLEO p/p: 0.6% @ 1GeV E/E: 2.2% @ 1 GeV 5% @ 100 MeV PID(/K):  > 90% mis < 5%

  35. (Similar comments apply for DS) “D Tagging”(AKA “The MarkIII Method”) + e Basic Strategy (most CLEO-c analyses): • Full reconstruction of one D meson decay into hadrons (“Tag D”) • Search remainder of event for signal D decayhadronic or (semi-)leptonic e.g. B(D+ K-++) = #(K-++) in tagged events ( (K-++) * #tags ) • Tag efficiency ~20% D+, 30% D0 K+K-p+ Single tags are clean Compute m(D)rec with ED=Ebeam and pD from reconstructed decay products; resolution improves greatly Continuum,  pair, radiative return events suppressed significantly. m(D cand)rec (GeV)

  36. Expected #ST: Expected #DT: Since eij  ei ej, correlated systematics cancel in NDD To first order, Bi is independent of tag modes’ efficiencies, s,L. D Hadronic BF (Cabibbo-Favored) Use 3 D0 and 6 D+ modes - Count #Single Tags (ST): Niobs(9) - Count # Double tags (DT): Nijobs (45) Double Tagged, 281 pb-1 • Update from 56 pb-1 to 281 pb-1 soon • Some systematics still being studied. • O(1%) stat & syst errors on golden modes in sight… 56pb-1 CLEO PRL 95, 121801 (2005) Refer to CLEO talks by Steven Blusk

  37. p+p0 p+p+p- p+p0p0 p+p+p-p0 p+p+p+p-p- K-p+p+ p+p-p0 p+p- p0p0 p+p- p+p- p+p- p0p0 p+p- p+p-p0 D Hadronic BF (Cabibbo-Suppressed) • First observations… untagged  281pb-1  CLEO PRL 96, 081802 (2006) • Isospin Analysisof pp final state • A2/A0 = • 0.420±0.014 ±0.010 • Strong phase shift: • = (86.4±2.8±3.3)0 Large FSI in D decays.   Other first/improved BF’s D0hp0, wp+p-, D+hp+

  38. Measurement of D KL0 CLEO preliminaryhep-ex/0607068 Reconstruct entire event, except for Kl0, and plot missing mass squared:Mmiss2=(pD-pp)2 (6 tag modes) ~2000 signal events • Expect due to interferencebetween and . 281 pb-1 data ~1100 signal events (3 tag modes)

  39. DKL0p Results and the Strong Phase CLEO preliminaryhep-ex/0607068 uncertainty due B(DKS0) First measurements! not including p0 systematic • Results: • B(D0KL0p0) = (0.940 ± 0.046 ± 0.032)% • B(D+KL0p+) = (1.460 ± 0.040 ± 0.035 ± 0.009)% • Also measure B(D0Ks0p0) = (1.202 ± 0.016 ± 0.039)% • Asymmetries: • R(D0) = 0.122 ± 0.024 ± 0.030 • R(D+) = 0.030 ± 0.023 ± 0.025 Expected Asymmetries Isospin decomposition of D to K pi amplitudes: 6 parameters, 7 measurements

  40. acc by PRDCLEO-Conf-06-15 D0K+K-p0 Dalitz Analysis Similar fitting technique to Dp+p-p+ analysis Key inputs to g ~9 fb-1 on/just below(4S) Reconstruct D*+D0p+, D*-D0p- pcharge tags the D0 flavor at prodn K*- 735 candidates f K*+ K*+ Read off the values from the DP fit rD= 0.52±0.05±0.04 dD = (332±8±11)o • First measurement of dD. • Significant improvement on rDover previous value using K*K BF’s

  41. Ecm=4160 MeV Simulations < DE > = 0 DsDs* DD DsDs DD* D*D* CLEO preliminary • Scan the region 3970-4260 MeV • Optimize Ds physics • Study D(s) XS in this region • Confirm Y(4260) The Ds Scan • No need to reconstruct D*, as Mbc differentiates event types. • For DD and DsDs cut on E and use Mbc to extract yields. • For other event types cut on Mbc and use invariant mass to extract yield. • 12 scan points • ~60 pb-1 (total) • Ecm=4170 selected • Additional 180 pb-1collected at 4170 MeV

  42. Ds+, Ds-combined Exclusive DsHadronic Decays • Follows very similar procedure as for y(3770)DD • Kinematic variables: cut on Mbc, fit in M(Ds) • Look at 6 modes: KsK+, K+K-p+, K+K-p+p0, p+p-p+,hp+,hp+ • Single tag yields ~0.4-4k, double tag yields up to ~100 KKp single tag events, signal fit in each m(KK) bin Yield Br(Ds-K+k-p- )= (5.57 ±20 ±20 )% CLEO determines partial branching fraction: m(K+K-) within m(f)±10 MeV: 1.98±0.12±0.09% (~x2+O(10%)) K+K- mass m(f) CLEO preliminaryhep-ex/0607079 Better to use K+K-+ as normalizing mode

  43. K- K+ - e+ Semileptonic Reconstruction at (3770) 281pb-1: ~310k D+, ~160k D0 tags Semileptonic decays are reconstructed with no kinematic ambiguity Signal events: U = Emiss– |Pmiss| = 0 ~7000 events (log version with tails later) U = Emiss– |Pmiss| (GeV) Tagging creates a single D beam of known 4-momentum Refer to CLEO talk by Yongsheng Gao

  44. 69928 679684 29520 291055 U = Emiss– |Pmiss| (GeV) D  p/KenBranching Fractions & Form Factors With 281/pb D tagging 134749 14397132 45029 584688 Emiss and Pmiss are missing energy and momentum of the event Plots Integrated over all q2

  45. D ,Ken Branching Fractions Comparison D → K e+ ν D → π e+ ν Good consistency between measurements. LQCD precision lags experiment.

  46. Form Factors as a Stringent Test of LQCD Shape α LQCD LQCD C. Aubin et al., PRL 94 011601 (2005). DATA FIT CLEO preliminary LQCD DATA FIT Vcd = 0.22380.0029 LQCD lags exp. Vcs = 0.97450.0008(CKM unitarity)

  47. Vcs and Vcd Results CLEO preliminary Combine |Vcx|f+(0)valuesfrom fits with unquenched LQCD results forf+(0) (Phys. Rev. Lett. 94, 011601 (2005)) to extract |Vcs| and |Vcd|. Tagged and untagged consistent. 40% of events are common to both analyses: DO NOT AVERAGE!Uncertainties: experiment: Vcs <2%, Vcd~4% / LQCD: 10% Vcs (Wcs LEP) and Vcd (vN) well measured  good agreement between PDG(HF) and CLEO-c results primarily a check of the LQCD value for f+(0). Nevertheless, the most precise & robust Vcs & Vcd determinations using semileptonic decays to date.

  48. CLEO preliminary 32.7  6.7 Rare semileptonicD decays D0K-p+p-e+ne 8.5 +4.5-3.2 ICHEP conf paper D+we+n 13.3  4.0 37.3  6.7 * First observation ** Improved UL (factor 100) *** Error halved D tagged, 281pb-1

  49. Simultaneous fit to D+ 0e , D0 -e Rv = 1.40  0.25  0.03 R2 = 0.57  0.18  0.06 D tagged, 281pb-1 Dren (BR+FF) cos  Interest: 1st measurement of FF in Cabibbo suppressed charm PS V decay q2 Need DK*en and Dren FF Grinstein & Pirjol [hep-ph/0404250] D+ 56pb-1 281pb-1 cos e  Line is projection for fitted RV, R2 Fixed background shape and signal tails from MC 56pb-1 D0 B(D0 -e+)= (1.560.160.09)10-3 B(D+ 0e+)= (2.320.200.12) 10-3 Isospin average: G(D0  r-e+n) = (0.410.030.02)10-2 ps-1 281pb-1 CLEO preliminary

  50. Inclusive Semileptonic Results Consistent with the known exclusive modes saturating the inclusive branching fractions . Extrapolated below 0.2 CLEO-c 281pb-1, D Tagged hep-ex/0604044, subm to PRL Consistent with isospin symmetry

More Related