1 / 36

SuperKEKB B factory

SuperKEKB B factory. April 12, 2006 FPCP@Vancouver Nobu Katayama (KEK). Outline. Physics cases at Super KEKB Accelerator parameters and R&D status Detector R&D status. Super KEKB.

billie
Download Presentation

SuperKEKB B factory

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. SuperKEKB B factory April 12, 2006 FPCP@Vancouver Nobu Katayama (KEK)

  2. Outline • Physics cases at Super KEKB • Accelerator parameters and R&D status • Detector R&D status N. Katayama

  3. Super KEKB • Asymmetric energy e+e- collider at ECM=m((4S)) to berealized by upgrading the existing KEKB collider. • Super-high luminosity  41035/cm2/sec 510 9 BB per yr.  410 9t +t - per yr. Belle with improved rate immunity Higher beam current, more RF, smaller by* and crab crossing  L = 41035/cm2/sec http://belle.kek.jp/superb/loi N. Katayama

  4. More questionsin flavor physics • Are there New Physics phases and new sources of CP violation beyond the SM ? • Compare CPV angles from tree and loops. • Are there new flavor-changing interactions with b, c or t? • bsnnbar, D-Dbar mixing+CPV+rare, tmg • Are there right-handed currents ? • bsg CPV, BV V triple-product asymmetries f b s Can we answer such questions at a Super B Factory? B _ d _ s s Ks _ d N. Katayama

  5. Search for new CP phases In general, new physics contains new sources of flavor mixing and CP violation. 4In SUSY models, for example, SUSY particles contribute to the bs transition, and their CP phases change CPV observed in BfK, h’K etc. SM only 0.2 0.4 ASUSY ASM | | 0.6 0.8 SM SUSY contribution In general, if SUSY is present, the s-quark mixing matrix contains complex phases just as in the Kobayashi-Maskawa matrix. Effect of SUSY phase qSUSY on CPV in BfK decay N. Katayama

  6. Sensitivity to new CP phases Estimated error in the measurement of time dependent CP violation Discovery region with 50 ab-1 |ASUSY/ASM|2 We are here qnew physics (For a particular set of SUSY model/parameters) N. Katayama

  7. Search for new flavor mixing l + l - : Probe the flavor changing process with the “EW probe”. g, Z0 b quark s quark This measurement is especially sensitive to new physics such as SUSY, heavy Higgs and extra dim. ? Theoretical predictions for l +l - forward-backward charge asymmetry for SM and SUSY model with various parameter sets. Possible observables: • 4Ratio of branching fractions • 4Branching fraction • 4CP asymmetry • 4q 2 distribution • 4Isospin asymmetry • 4Triple product correlation • 4Forward backward asymmetry • 4Forward backward CP asymmetry The F/B asymmetry is a consequence of g-Z0 interference. N. Katayama

  8. Sensitivity to new flavor mixing Sensitivity at Super KEKB Experimental result with 0.35 ab-1 Belle, 2005 Standard model MC, 50 ab-1 4Zero-crossing q2 for AFB will be determined with 5% error with 50ab-1. These patterns were excluded by recent data from Belle. N. Katayama

  9. mb ms ms mb Belle Update 2005 (386 x 106 B pairs): Search for Right-Handed Currents in BKS0g Poor tags Good tags Use the KS to determine the vertex. hep-ex/0507059 (MX<1.8 GeV) In the SM, S should be close to zero (<0.10). SM: γ is polarized, the final state almost flavor-specific. N. Katayama

  10. Present Belle (stat.) 5ab-1 50ab-1 S(BK*g, K*Ksp0) 0.52 0.14 0.04 NP and Right-handed currents in bgsg D.Atwood, M.Gronau, A.Soni (1997) D.Atwood, T.Gershon, M.Hazumi A.Soni (2004) • tCPV in B0g KSp0g • mheavy/mb enhancement for right-handed currents in many NP models • LRSM, SUSY, Randall-Sundrum (warped extra dimension) model • LRSM: SU(2)LSU(2)RU(1) • Right-handed amplitude mt/mb :  is WL -WR mixing parameter • for present exp. bounds ( < 0.003, WR mass > 1.4TeV) |S(Ksp0g)| ~ 0.5 is allowed. • Here an asymmetry does not require a new CPV phase N. Katayama

  11. “B meson beam” technique d(Br)/Br = 2.5% at 50 ab-1 B e- e+ Υ B p D full reconstruction Constraint from BXsg BDtn 0.2~0.3% for B+ Sensitivity of H± search Application Btn (present) H±search in BgD(*)tn LHC 100fb-1 N. Katayama

  12. B tagging provides a “B-meson beam” MC extrapolation to 50 ab-1 5s Observation of B±gK±n n (compare to K++ννand KLgp0nn) Extra EM calorimeter energy N. Katayama

  13. A Super B Factory is also a powerful t-charm Factory • Rich, broad physics program that covers B, t and charm physics.. • Examples: • examination of rare charm modes • D0-D0bar mixing • searches for tmg with unprecedented sensitivity. N. Katayama

  14. ~ ~ m(e) ~ c 0 % t BR(tgmg) ~10-6  tan2b ~ 1 TeV (mL2)32 mL2 ( ) 4 mSUSY ~ Search for flavor-violating t decay g • SUSY + Seesaw • Flavor violation by n-Yukawa coupling. • Large LFV t Br(tmg)=O(10-7~9) m(e) Expected sensitivity at Super KEKB Present Belle Super-KEKB tlg tlp/h/h’ t3l tl Ks Gaugino mass = 200GeV tBg/p N. Katayama

  15. Search for New Physics in the Charm Sector c – the only heavy up-like quark experimentally accessible; New Physics Mechanisms may be different for u- and d-like quarks;  Rare Charm Decays, D-Dbar Mixing and CP Violation e.g. D0 → gg ; D0(±) → H0(±)l+l- ; D0 → l+l- ;D0(±) → V0(±)g N. Katayama

  16. Comparisons with LHCb • Clean environment measurements that no other experiment can perform. • Examples: CPV in BgfK0, B gh’K0 for new phases, BgKSp0g for right-handed currents. • “B-meson beam” technique access to new decay modes. • Example: discover BgKnn. • Measure new types of asymmetries • Example: forward-backward asymmetry in bgsmm, see • Rich, broad physics program including B, t and charm physics • Examples: searches for tgmg and D-D mixing with unprecedented sensitivity. N. Katayama

  17. Super KEKB accelerator

  18. Bunch length (s) • 7 ~ 9 mm -> 3 mm How to achieve the super-high luminosity Crab cavity N. Katayama

  19. Accelerator R&D • Vacuum components for higher current • Antechambers, coating, bellows, collimetors,, • Superconducting quadrupoles • High power RF components • Bunch-by-bunch feedback system • C-band linac • Beam diagnostics • Crab cavities N. Katayama

  20. Components to be upgraded Interaction Region Crab crossing q=30mrad. by*=3mm New QCS New Beam pipe More RF power Damping ring Linac upgrade N. Katayama

  21. Crab cavity: a new idea for higher luminosity • Head-on collisions with finite crossing angle ! • avoid parasitic collisions • collisions with highest symmetry  large beam-beam parameter N. Katayama

  22. We are here • First performance report expected in fall 2006 • Factor ~2 gain in Lpeak may be expected within ~2 yrs • ~31034cm-2s-1 within our reach fall N. Katayama

  23. Super KEKB components Bellows Antechamber MO-flange C-band RF cavity N. Katayama

  24. N. Katayama

  25. Super KEKB: Proposed schedule Lpeak (cm-2s-1) Lint 1.5x1034 470 fb-1 4x1035 10 ab-1 5x1034 1 ab-1 5x109 BB/yr. & also t+t- Crab cavity N. Katayama

  26. Detector requirements and R&D status

  27. Requirements for the detector Issues 4Higher background ( 20) 4Higher event rate ( 10) 4Require special features • radiation damage and occupancy • fake hits and pile-up noise in the EM - higher rate trigger, DAQ and computing • low pm identification f smm recon. eff. • hermeticity fn “reconstruction” Possible solution: 4Replace inner layers of the vertex detector with a silicon striplet detector. 4Replace inner part of the central tracker with a silicon strip detector. 4Better particle identification device 4Replace endcap calorimeter by pure CsI. 4Faster readout electronics and computing system. N. Katayama

  28. Super Belle Faster calorimeter with Wave sampling and pure CsI crystal Super particle identifier with precise Cherenkov device KL/m detection with scintillator and new generation photon sensors Background tolerant super small cell tracking detector New Dead time free readout and high speed computing systems Si vertex detector with high background tolerance N. Katayama

  29. 2-layer sensors at inner layer for robust vertexing R = 1 cm Si vertex det. & Tracker CDC SVD • 6 or more Layers • Large area Si tracker • Self tracking of low momentum tracks. • Dead time less readout at the luminosity of 5x1035/ cm2/sec. • Rejection of beam background that is 30 times severer than that in KEKB. • Smaller cell size • Lower hit rate for each wire. • Shorter maximum drift time. • Faster drift velocity • Shorter maximum drift time N. Katayama

  30. Monolithic Active Pixel Sensor (MAPS) and Silicon striplet MAPS 10mm • Key Features • Thermal charge collection (no HV) • Thin - reduced multiple-scattering, g conversion, background g target • NO bump bonding – fine pitch possible (8000x geometrical reduction) • Standard CMOS process - “System on Chip” possible X and Y (long) strip configuration U and V short strip configuration N. Katayama

  31. CAP3 – full-sized! 21 mm Active area 20.88 mm >93% active without active edge processing 928 x 128 pixels = 118,784 ~4.5M transistors ! N. Katayama

  32. CAP3: Full-size Detector Half ladder scheme CAP3 Pixel Readout Board (PROBE) 5-layer flex PIXRO1 chip 128 x 928 pixels, 22.5mm2 ~120 Kpixels / CAP3 0.25 mm process End view Side view Double layer, offset structure Length: 2x21mm ~ 4cm r~8mm r~8mm 17o 30o e- e+ # of Detector / layer~ 32 N. Katayama

  33. TOP counter • Cherenkov ring imaging using timing information Difference of path length  Difference of time of propagation (TOP) (+ TOF from IP) With precise time resolution (s~40ps) N. Katayama

  34. GaAsP photo-cathode Higher Q.E. at longer wavelength → less chromatic error 3.5s K/p at 4GeV/c, q=70ﾟ (1s improvement) Square-shape MCP-PMT with GaAsP photo-cathode is developing with Hamamatsu Photonics Light propagation velocity inside quartz MCP-PMT with GaAsP Photon sensitivity at longer wave length shows the smaller velocity fluctuation. N. Katayama

  35. Wave form, ADC and TDC distributions Enough gain to detect single photo-electron Good time resolution (TTS=42ps) for single p.e. Slightly worse than single anode MCP-PMT (TTS=32ps) Next Check the performance in detail Develop with the target structure Single p.e. 0.5ns/div 20mV/div count count pedestal 4000 TTS～42ps 600 single photon peak 3000 400 2000 Gain～ 0.96×106 200 1000 0 100 125 150 175 0 -10 0 10 20 1bin/0.25pc adc tdc GaAsP MCP-PMT performance 1bin/25ps N. Katayama

  36. Summary of Super KEKB upgrade • Why? – Search for new sources of flavor mixing and CP violation • How? – Increase NB, decrease by*, and crab crossing: L=41035/cm2/s • New beam pipe, crab cavity, new injector with damping ring • Belle will also be upgraded • Ideas for even higher luminosity and better detector are desperately needed • Please join and help! N. Katayama

More Related