1 / 39

Super KEKB project

Super KEKB project. WIN03 Oct 9 th , 2003 Nobu Katayama KEK. Outline. Belle/KEKB status Super KEKB plan Physics Detector study Accelerator study. KEKB status 1999/10 - 2003/7/1. 1.057  10 34 cm -2 s -1. > 50 fb - 1 in years 2002, 2003. LER~1.55A HER~1.1A With SRF. 158.7 fb -1.

crescent
Download Presentation

Super KEKB project

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. Super KEKB project WIN03 Oct 9th, 2003 Nobu Katayama KEK

  2. Outline • Belle/KEKB status • Super KEKB plan • Physics • Detector study • Accelerator study Nobu Katayama

  3. KEKB status1999/10-2003/7/1 1.0571034 cm-2s-1 > 50 fb-1 in years 2002, 2003 LER~1.55A HER~1.1A With SRF 158.7fb-1 Nobu Katayama

  4. Best day (May 12th, 2003) 579.1 pb-1/day recorded Nobu Katayama

  5. SVD 1  SVD 2 RBP 1.5 cm RBP 2.0cm RL1 2.0cm RL1 3.0cm Rout 8.8cm Rout 6.0cm 8+10+14= 32 ladders 6+12+18+18= 54 ladders SVD1 SVD2 Nobu Katayama

  6. How much improved? Nobu Katayama

  7. We have just started! More and more Bs  Super KEKB

  8. Mission of Super B Factory(ies) Bread’nd butter for B factories Mission 1: 300 fb-1 Precision test of KM unitarity See quantum effect in penguin and box loop Mission 2: 3,000 fb-1 Search for new physics in B and t decays Mission 3: 30,000 fb-1 Identify SUSY breaking mechanism Very important if New physics = SUSY Nobu Katayama

  9. In which processes can we find New Physics? • Rare decays • B  Xsg ,rg • B  K*mm • CP violations • B fKSandh’KS • B  Xsg , rg • b c emitting charged Higgs • Forbidden decays by SM • Forbidden/rare decays of t Nobu Katayama

  10. CPV in penguin decays Prove ACP(fKS, h’KS)≠ACP(J/yKS) In SM, 5sdiscovery fKS K+K-KS h’KS ACP New phase in penguin loop may change this relation Belle (August 2003) ACP(fKS)=-0.96±0.50 ACP(h’KS)=+0.43±0.27 KEKB PEP-II Next B factory ACP(J/yKS)=+0.731±0.057 Nobu Katayama

  11. Atmospheric Neutrinos Can Make Beauty Strange? • Leptogenesis models inspired by the naïve SO(10) unification exist where the near-maximal mixture of nt and nm results in large mixing of RH super-b and super-s, giving O(1) effects on bs transitions such as • Asymmetry in B fKs (effect is in first order) • Bs mixing • b  sg (effect is of the order of |Cg(NP)|2) • Ref. R. Harnik, D. Larson, H. Murayama and A. Pierce (hep-ph/0212180), D. Chang, A. Masiero and H. Murayama (hep-ph/0205111) • Many other GUT inspired models are coming up! Nobu Katayama

  12. Dominant Right-Right Mixing case Nobu Katayama

  13. SUSY effect in BK*mm F/B asymmetry m(mm)2 distribution A.Ali SUSY models with various parameters set SM • These measurements are excellent probe to search for SUSY • Inclusive decay, bsll, is much less model dependent. An e+e-B factory provides a unique opportunity to measure this by pseudo reconstruction technique Nobu Katayama

  14. Rare decays of t Nobu Katayama

  15. Charged Higgs in tree decay • Large branching fraction: ~1% • Uncertainty in form factor cancels • in the ratio G(BgDtn)/G(BgDmn). • t polarization is more sensitive to H±. BD(*)tn vs. D(*)mn M.Tanaka +/- Nobu Katayama

  16. Comparison with an LHC experiment G(BDtn)/G(BDmn) at B factory with 5,000 fb-1 B factories don’t really do tree diagrams of new particles with the exception of charged Higgs… But together with LHC measurements, we can determine tanb! Nobu Katayama

  17. What can we do? Compilation at the 5th High Luminosity WS Nobu Katayama

  18. KEKB upgrade strategy larger beam current smaller by* long bunch option crab crossing L~1036 ILER=20A Constraint: 8GeV x 3.5GeV wall plug pwr.<100MW crossing angle<30mrad dt =3000fb-1 L=1035 before LHC!! ILER=9.4A One year shutdown to: replace vacuum chambers double RF power upgrade inj. linac g C-band Present KEKB L=1034 ILER=1.5A2.6A dt =500fb-1 2002 03 04 05 06 07 08 09 10 11 Nobu Katayama

  19. Detector upgrade • Higher luminosity collider will lead to: • Higher background • radiation damage and occupancy in the vtx. detector • fake hits in the EM calorimeter • radiation problem in the tracker and KLm detector • Higher event rate • higher rate trigger, DAQ and computing • Require special features to the detector • low pm identification for smm reconstruction eff. • hermeticity for n “reconstruction” Nobu Katayama

  20. Detector upgrade: an example Aerogel Cherenkov counter + TOF counter SC solenoid1.5T “TOP” + RICH 3.5GeV e+ CsI(Tl) 16X0  pure CsI (endcap) 8GeV e- Tracking + dE/dx small cell + He/C2H5  remove inner lyrs. New readout and computing systems Si vtx. det. 3 lyr. DSSD m / KL detection 14/15 lyr. RPC+Fe  2 pixel lyrs. + 3 lyr. DSSD  tile scintillator Nobu Katayama

  21. SVD occupancy and CDC hit rate • Current most inner layer of SVD’s occupancy is 3~5% • Current most inner layer of CDC’s occupancy is 2~3% • With 1035 luminosity, two layers of pixel + silicon (~15cm R) + CDC survives • With 1036 luminosity, Pixel + Silicon a la super BaBar design? Cathode Inner Main Radius = 15cm Nobu Katayama

  22. Does CDC work with L>1035 ? • Smaller cell • Faster gas • Larger starting diameter Yes !! Nobu Katayama

  23. Small Cell Chamber (with SVD2) ~20cm Nobu Katayama

  24. XT curve for small cell measured Normal cell Small cell Nobu Katayama

  25. New PID detector Requirements: - Thin detector with high rate immunity - >3s p/K separation up to 4GeV/c - low pp/m separation TOP counter for barrel & Aerogel RICH for endcap Present Belle: Aerogel Cherenkov counter both for barrel and endcap. Nobu Katayama

  26. Time of propagation (TOP) counter photon hits Reflection mirror 200mm 20mm A few meters Fused silica(n=1.47) time & X sensitive PMTs Nobu Katayama

  27. Aerogel RICH for endcap • Hit distribution • Single event display Nobu Katayama

  28. Super KEKBAccelerator upgrades

  29. What’s impressive about KEKB • KEKB and PEP-II have achieved the highest luminosities in history of particle accelerator/collider • KEK and PEP-II have recorded more than 140 fb-1 of data and continue to accumulate • Thanks to tremendous efforts by and ingenuity of the commissioning and operation groups Nobu Katayama

  30. Features of KEKB • Super conducting RF cavities and ARES cavities • Holds more than 1A of beam current with SRF • IR region • 3m100m: the smallest beam size among the storage rings • Finite crossing angle • Solenoids for positron ring • Suppress photo-electron clouds • Flexible Optics • Real time monitor and correction system Nobu Katayama

  31. Challenges with Super KEKB • High beam currents (LER 9.4A+HER4.1A) • Heating, breakdown will occur • Ultra high vacuum, beam lifetimes • Power consumption (80~100MW) • Stability of the beam/photo electron clouds • Injection • Noise/Background to detector • Beam-beam effect (tune shift of 0.05 assumed for 1035) • Beam-beam tune shift; unknown • For a double ring machine, more than 50 parameters must be optimized simultaneously • Hard to maintain the optimum beam conditions due to disturbances • Optics with very small focusing depth (3mm) • KEKB vertical beta is <6mm (world record) • Shorter bunch length:=more peak current gives more power dissipation, shorter lifetime Nobu Katayama

  32. Towards Super KEKB • LER 9.4A + HER 4.1A (4~6 times as now) • Rewind solenoids • Double RF systems • Replace vacuum chambers of the both rungs • Cooling system • More focusing and shorter bunch (half as now) • New IR • Charge switch and better/faster injection • 8GeV positron injection with a C-band linac • Damping ring • New positron production target • Crab crossing Nobu Katayama

  33. Accelerator Upgrades for Super KEKB • Crab cavities • Super Belle • New beam pipe & bellows • New IR • More RF sources • More cavities • Damping ring • Charge switch by C-band • Positron source K. Oide @ Izu 2003 Nobu Katayama

  34. Machine parameters bx = 20 cm bx = 15 cm Nobu Katayama

  35. Crab cavity developments xy ◊ ◊ ◊ ◊ ◊ • Crab crossing may boost the beam-beam parameter up to 0.2! (Strong-weak simulation) K. Ohmi Head-on(crab) (Strong-strong simulation) crossing angle 22 mrad • Superconducting crab cavities are under development, will be installed in KEKB in 2005. K. Hosoyama, et al Nobu Katayama

  36. 50% more RF cavities Double # of Klystrons D1 D2 5 buildings should be added. (Each building for 4〜6 RF units.) #RF/#SRF 30/8  44/12 HER-RF (ARES) new D11 new D4 HER-RF (SCC) LER-RF (ARES) D10 new D5 #Kly/ACPW(MW) 23/45  56/73 new new D8 D7 Nobu Katayama

  37. Energy exchange(HER : e+/LER : e-) • Advantages : • Effect of photoelectron cloud can be reduced. • Positron energy increases. • Injection time can be reduced. • Intensity of injector : e- > e+ • Beam current : e- > e+ • Unknowns : • Multipactering occurs in e+ at HER or not ? • Height of vacuum chamber is smaller than LER. • Is fast ion instability safe for e- in LER ? • Electron energy decreases. • Major upgrade of injector linac is needed. • Energy upgrade : C-band scheme Nobu Katayama

  38. Linac upgrades for 8 GeV e+ S-band accl. units are replaced with C-band units. Accl. Field 21 -> 41 MV/m 2-Bunches for Simultaneous Injection 1-st bunch -> e- Injection 2-nd bunch -> e+ production e+ Damping Ring for lower emittance • Achieved • 40 MW (0.5ms, 50pps), • > 40 MV/m (1m structure) Goal: 40 MW 40 MV/m Nobu Katayama

  39. Summary • Belle and KEKB have achieved 1.06×1034 cm-2s-1 and 158 fb-1 • We have installed SVD2, two more RF cavities and come back online in 2 wks • We are hoping to upgrade KEKB and Belle to reach 1035 luminosity and to accumulate 3000fb-1 before 2010 when LHC starts producing results • Simulation tells us that we may reach 51035 with head-on collision with crossing angles using the crab cavities Nobu Katayama

More Related