1 / 44

CLEOC/BESIII— New Frontiers of  -C Physics

CLEOC/BESIII— New Frontiers of  -C Physics. Z.G. Zhao University of Michigan, Ann Arbor, MI, USA IHEP of CAS, Beijing, China. I . CLEOC /CESRC and BESIII /BEPCII II. Physics Over View III. Current Status Suggestions to BESIII V. Summary. . KEKB. PEPII. BEPCII.

cassidy-shelton
Télécharger la présentation

CLEOC/BESIII— New Frontiers of  -C 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. CLEOC/BESIII—New Frontiers of -C Physics Z.G. Zhao University of Michigan, Ann Arbor, MI, USA IHEP of CAS, Beijing, China I . CLEOC/CESRC and BESIII/BEPCII II. Physics Over View III. Current Status • Suggestions to BESIII V. Summary

  2. KEKB PEPII BEPCII CESR VEPP-2000 CESR-C Factory Peak Luminosity (1/1030 cm-2s-1) VEPP-4M DAFNE BEPC VEPP-2M Current Operating e+e- Colliders -c B

  3. CESR-C CESR • Modify CESR for low-energy operationCESR-C; • Add wigglers for transverse cooling

  4. CLEOC 1.5 T now,... 1.0T later 93% of 4p sp/p = 0.35% @1GeV dE/dx: 5.7%p @mip 83% of 4p 87% Kaon ID with 0.2% p fake @0.9GeV 93% of 4p sE/E = 2% @1GeV = 4% @100MeV Trigger: Tracks & Showers Pipelined Latency = 2.5ms Data Acquisition: Event size = 25kB Thruput < 6MB/s 85% of 4p For p>1 GeV • State of art detector, well understood • Replace silicon strip tracker with 6 layer inner drift chamber

  5. RF SR RF Ecm=2~5.16 GeV Luminosity~1033 cm-2s-1 (optimized at 3.68 GeV) + - e e IP BEPC II — Double Ring

  6. Magnet: - 0.4-0.5 T existing BESII magnet - 1 T Super conducting magnet BESIII CDC: xy=50 m MDC: xy=130 m sp/p = 0.5% @1GeV dE/dx=6% p @mip TOF: T = 80 ps Barrel 100 ps Endcap EMCAL: sE/E = 2.5% @1GeV z = 0.5 cm/E Muon ID: 9 layer RPC Trigger:Tracks & Showers Pipelined; Latency = 2.4ms • Be competitive to CLEOC • Almost a completely new detector Data Acquisition: Event size = 12kB Thruput ~50 MB/s

  7. (3770) BEPCII CESRC Physics Features in -c Energy Region

  8. Physics Features in -c Energy Region • Transition between smooth and resonances, perturbative and non-perturbative QCD • Rich of resonances, charmonium and charmed mesons. • Newtype of hadronic matterare predicted in the region, e.g. glueball and hybrid • Threshold characteristics, large , low multiplicity, pure initial state, S/B optimum

  9. A Typical Hadronic Event in CLEOIII/BESII Hadronic events from BESII R scan CLEO

  10. Key Issues in Particle Physics Verify the SM The test of the SM has been dominating exp. HEP for about three decades. Establish and test strong-coupled, nonperturbative quantum field theories Still the foremost challenge in modern physics The effects of the strong interactions non PQCD permeate every experimental measurement involving quarks and are an obstacle in almost every attempt to extract precision electroweak physics from data. Probe new physics beyond the SM It’s of profound importance to • systematically study the weak interactions that mix quark and lepton flavor • complete understand QCD Precision data is badly needed to enable a comprehensive mastery over non PQCD and to calibrate and validatethe theoretical technology

  11. CKM and LQCD

  12. B decay D decay Mixing CKM Matrix • CKM, fundamental parameters in nature that reflect the flavor • and generation mixing, is induced by weak interaction. • Cannot be predicted within the SM and must be determined • by experiment. • Charm decays is a unique laboratory to determine directly Vcd • and Vcs, indirectly Vub and contribute to Vcb.

  13. Lattice QCD • LQCD is the only compete definition of QCD. It includes both perturbative and non perturbative QCD. • LQCD is not a model. - The only parameters are s and the quark masses. - Relates B/D physics to Y/ physics and to glueball physics to … • Predict to ~15% accuracy for a wide range of masses (include glueball and hybrid), decay constants, form factors for many conventional hadrons. • The challenge for LQCD is to demonstrate reliability at the level of a few percent accuracyrequire wide range of highly precision experimental data

  14. LQCD Predictions for Glueball Masses Lowest Lying States: Scalar 0++, M ~ 1.6 GeV Tensor 2++, M ~2.3 GeV Pseudoscalar, M ~ 2.5 GeV QCD is not understood until we understand gluonic degree of freedom in the spectrum, glueballs and hybrids.

  15. The CLEOC Program Act I (2003): (3770) 3 fb-1 30M events, 6M taggedD decays Act II (2004): ~ 4100  3 fb-1 1.5M DsDs, 0.3M taggedDs decays Act III (2005):(3100)  1 fb-1 1 billion J/ decays Focused data samples to collect and clear physics goals to reach.

  16. Precision Standard Model Tests • Absolute hadronic charm branching ratios with 1-2% errors • fD+ and fDs at ~2% level • Semileptonic decay form-factors (few % accuracy) Contribute to CKM Measurements

  17. Absolute Branching Ratios Decay Mode PDG2000 CLEOC (dBr/Br %) (dBr/Br %) D0 Kp 2.4 0.5 D+ Kpp 7.2 1.5 Dsfp 25 1.9 Set absolute scale for all heavy quark measurement

  18. fD+ and fDs • LQCD can predicts fB/fD and fBs/fDs. Measure fD, fDsgive fBand fBs, thus determine Vt d and Vts • Similarly measure fD/fDschecks fB /fBs CLEOC Expected Precision in Decay Constants Decay Mode Decay Constant fDq/fDq (%) D+ + fD2.3 Ds+ + fDs 1.7 Ds+ + fDs 1.6

  19. Weak physics Strong physics Semileptonic Form Factors Semileptonic decay severe as excellent laboratory to study both weak and strong interaction e.g. D+ Kl Decay Mode / CKM Element CKM Precision D0 K-e+ 1.2% |Vcs| 1.6% D0 -e+ 1.5% |Vcs| 1.7%

  20. How Much CLEOC Can Improve CKM Present After CLEOC

  21. Other Interesting Topics

  22. Test of the SM and QCD in Continuum • R scan2-5 GeV (2~3%) Evaluating QED, a’ mHiggs,high precision test of SM, hunting for new physics beyond the SM; structures of high mass  region • Large hadronic events sampleat point (2-3GeV) - Multiplicity: second binomial momentum R2 [nch(nch-1)/nch2] = 11[1-cs(s)]/8 NLQCD - =-ln(p/s) distribution for charged particles MLLA, LPHD - Hadronic events shape: thrust, transverse moment distribution pQCD, power correction - (e+e- 2/4 /K); e+e-  /K+X; Polarized parton density, S/U universality; quark and glue fragmentation(combine with J/ data) • Charmed baryons pQCD, string fragmentation, HQE and duality

  23. Relative Uncertainty Contribution to a and (Mz2) without BES R Data

  24. CLEO CMD,SND KROE BESIII,CLEOC Relative Contribution in Magnitude and Uncertainty

  25. Peak Position of  Second Order Momentum

  26. S/U Universality MeanThrust

  27. J/ and (2S) Decays J/ decays • Search for new forms of matter - Glueballs: h(1440),f0(1370), f0(1500), f(1700), fJ(2000) - Exotic mesons: 0--, 0+-, 1-+, 2+- p1(1400), p1(1600), • Study of excited baryonic states (N*, *, *, *... ) (2S) decays • Search for missing or unconfirmed states: 1P1, c’ • Measure hadronic branching fraction ( puzzle) • Measure radiative transition rate • Study of cJ states Best laboratory to elucidate a tricky situation; unique opportunity for QCD studies and new level of understanding

  28. New Study of the  Lepton • Lower limit on mat sub 10 MeV level • Determination of m0.1 MeV • Precision measurement of key Br. (,0) • Measure Michel parameters • Direct search for non-SM physics

  29. Searches and New Physics • D0D0bar mixing • CP violation in , J/, (2S) decays • Lepton flavor violating processes e.g. J/’, =e, ,  • Rare decays --X, e-G, -……. J/DX Taking advantage of threshold production, much high statistics and low background

  30. Why CLEOC in B Factory Era • Some important measurements at B’s arelimited bysystematical uncertainty • CLEOC enjoys threshold production, large production cross section, low multiplicity, low BG, high S/B. But limited by statistics

  31. CLEOC: 2003: y(3770) -- 3 fb-1; 30 M 2004: 4100 -- 3 fb-1; 1.5M DsDs 2005: y(3100) -- 1 fb-1; 1 Billion J/y BESIII BEPCII CESRC Why BESIII in CLEOC Era?

  32. Why BESIII in CLEOC Era? • Three years CLEOC program does not cover all the interesting physics in c energy region - 2-3 GeV, 2-3% R scan in 2-5 GeV - physics of  and (2S) - Charmed baryon • Need higher statistics for searches (glueball, exotica), rare decay, D0-D0bar mixing, CP and further improve the precision measurements. • New discoveries needs to be confirmed or continued. New type of matters, need high statistics to study it’s properties.

  33. Is BESIII Worth Doing? YES if L~1033 cm-2s-1 and BESIII is competitive to CLEC, and the commissioning is not too late Otherwise NOT really

  34. Possible Side Product • Cosmic ray experiment e.g. low energy (E<10 GeV)  spectrum. Important for SupperK  experiment L3CBESIII-C (cosmic exp.)

  35. Suggestions to BESIII/BEPCII • BEPCII: L~1033 cm-2s-1; BESIII compatible to CLEOC • Learn experiences and lessons from the other successful labs. Utilize ONLYmature technology. • Don’t use highest version of hardware and software. • Build a workable, reliable system has the highest priority. Don’t try to design fancy systems which is difficult for one to learn and use. • Set up an active international collaboration. A team that can committed and devoted to the project is essential • Select or train qualified experts in charge of each sub-system is of profound importance for the success of the project

  36. Suggestions to BESIII/BEPCII • Prototype, R&D work should be done as early as possible • Additional attention should be paid to - overall detector/ machine integration - alignment and monitoring - IR region - trigger - detector simulation, database, computing and network - better thermo isolation in detector hall (~12-28 0C) - better gas supply system (shorten the transportation distance, less T)

  37. CLEOC/CESRC Status • CESR/CLEO Program Advisory Committee Sept 28 2001 Endorsed CLEO-c • Proposal submission to NSF (October 15,2001) • Site visit on Jan/Feb 2002: Endorsed CLEO-c • Expect approval in Summer of 2002 • Wiggler prototype test successfully in vertical cryostat; now being installed in its horizontal cryostat. Will be put into CESR in July • Start building six layers CDC • Cost $3.5 M

  38. Status of BEPII/BESIII • Feasibility Study Report of BEPC II has been submitted to the funding agency. • Technical Design Report of BEPC II to be submitted soon. • Construction expected d to be started in 2003 and commissioning in 2007. • Cost $75 M (~1/3 for BESIII)

  39. CLEOC phys. run ? MARKIII BESII BESIII Engineer & phys. run BESIII Construction Interesting Schedule of CLEOC/BESIII CLEOC/CESRC: Wisely seizes the great opportunity; perfectly fills the gas in the frontier of weak and strong interactions BESIII/BEPCII: Nature extension. Will be a unique frontier of c physics for a decade after CLEOC.

  40. L(BEPCII) 3 L(CESR-C)  50L(BEPC) Peak Luminosity (1/1030 cm-2s-1) Typical Peak Luminosity of CESR-C, BEPC and BEPCII

  41. Additional Data for other physic topics Charm baryons at threshold, e.g. +- pairs at threshold R scan in 2-5 GeV; large hadronic event sample in 2-3 GeV Typical Dada Samples Proposed

  42. Summary • Physics in tau-charm energy region is sill very rich in the B’s era. • CLEOC/CESRC, a smartdecision that seizes great physics opportunities, is opening a new era of understanding weak and strong interaction. • BESIII/BEPCII, an nature extension of the only high energy physics base in China, will continue BESII and CLEOC’s mission to deepen the understanding of weak and strong physics, play a unique role in the precision test of SM, QCD and search for new physics in c sector.

  43. Tanks to Maury and CLEOC collaboration for the Information about CERSC/CLEOC Weiguo Li and BES collaboration for the information about BESIII/BEPCII Fred for many useful discussion about BES’s future

More Related