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Super B factory plan at KEK. Why, how, what, who, when and how much?. Super B Factory Workshop April 20-22, 2005 Honolulu. Masa Yamauchi KEK. Why? - Roadmap of B Physics. Identification of SUSY breaking mechanism. Anomalous CPV in b g sss. sin2 f 1 , CPV in B g pp ,
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Super B factory plan at KEK Why, how, what, who, when and how much? Super B Factory Workshop April 20-22, 2005 Honolulu Masa Yamauchi KEK
Why? - Roadmap of B Physics Identification of SUSY breaking mechanism Anomalous CPV in bgsss sin2f1, CPV in Bgpp, f3, Vub, Vcb, bgsg, bgsll, new states etc. if NP=SUSY Study of NP effect in B and t decays time or integrated luminosity Precise test of SM and search for NP Yes!! NP discovered at LHC(2010?) Discovery of CPV in B decays Now 400 fb-1
Motivations for Super KEKB 1. Possible anomalies observed in B decays • Once New Physics is discovered and its mass scale is determined, next is to study its flavor structure and CP violation, where B physics can play a unique role. • TCPV in b→sss ≠ b→ccs : 3.8s • Polarization in penguin dominated B→VV decays • ACP(B±→K±p0) ≠ ACP(B0→K±p ) ± These MUST be clarified. 2. New physics will be found soon at LHC. 3. e+e- B factory with L=3.5×1035 is competitive with LHCb.
Anomalous CPV hints new physics? Tree decay Belle + BaBar, 2004 b c J/y _ B c W _ s d _ KS d Ave. CPV = 0.726±0.037 equal if only SM 3.8s deviation observed Ave. CPV = 0.41±0.07 W top -hf x Sf penguin decay
Other Evidences for New Physics ACP(B→Kπ) fL (B→VV)
Comparison with LHCb SuperKEKB LoI hep-ex/0406071
A.Ishikawa 6th Workshop on Higher Lum. B Factories November 2004 Comparison • K*mm (which is Golden mode at LHCb) yield by LHCb is 2.7 times larger than K*ll yield by Super Belle. • Need 1036 machine and better detector(PID, vertex)/analysis. • A7 is fixed to the value obtained from bsg • LHCb cannot measure B(bsg), so they should use our value or float A7. 3 times better *just scaling Belle value with evts.
What? – SuperKEKB Design Interaction Region Crab crossing q=30mrad. by*=3mm New QCS New Beam pipe 8GeV (e+, 4.1A) 3.5GeV (e-, 9.6A) More RF power Damping ring • Increase beam currents • 1.6 A (LER) / 1.2 A (HER) • → 9.6 A (LER) / 4.1 A (HER) • Smaller by* • 6 mm→3 mm • Increase xy • 0.05→0.28(W-S) Linac upgrade L=3.5x1035cm-2s-1
Ante-chamber with solenoid field New crab cavity Ante-chamber Circular-chamber Build-up of electron clouds Super-KEKB (cont’d) • Head-on collision w/ Crab cavity Will be tested in 2006. • Ante-chamber /solenoid for reduction of electron clouds
KEKB Upgrade Scenario Lpeak = 1.41034cm-2s-1 Ltot = 330fb-1 (Nov.30, 2004) ~1010 BB/year !! & similar number oft+t- world records ! Major upgrade of KEKB & Belle detector (>1yr shutdown) SuperKEKB Crab cavities Lpeak (cm-2s-1) Lint 5x1034 ~1 ab-1 1.4x1034 330 fb-1 5x1035 ~10 ab-1
Belle Upgrade Aerogel Cherenkov counter + TOF counter g “TOP” + RICH CsI(Tl) 16X0 g pure CsI (endcap) Si vtx. det. 4 lyr. DSSD SC solenoid 1.5T g 2 pixel/striplet lyrs. + 4 lyr. DSSD Tracking + dE/dx small cell + He/C2H5 • remove inner lyrs. Use fast gas m / KL detection 14/15 lyr. RPC+Fe g tile scintillator New readout and computing systems
Q1: Does DC work with L=3.51035? • If NO, • Need Si tracker. • EM cal, solenoid and iron structure have to be rebuilt!! • If YES, • Upgrade the present Belle detector. New detector
Difference of QCS position is the reason Shower caused by over bend particle Pointed out by M.Sallivan in 6th HLWS (Nov,2004)
Rad. Bhabha BG sim. for Super-KEKB Barrel BWD EndCap FWD EndCap Realistic design based on discussion with QCS group Expected BG from other sources with heavy metal total ~ 1.5 ton L=25x1034/cm2/s ~4 % of total BG L=1034 /cm2/s
Super-KEKB (current) design Average Vacuum 5x10-7 Pa 1st layer
Does Belle-CDC work with L=3.51035 ? Exp 27 Run 206 HER 1.1A LER 1.5A L=9.6x1033cm-1s-1 Hit rate/wire(kHz) Cathode Inner Main Layer r = 15cm
2000 Layer 49 Layer 1 Layer 3 Layer 49 Layer 1 2002 Layer 3 Radiation damage to the present CDC Gain drift Efficiency for Bhabha tracks Bhabha ev. Number of hits Layer No rad. damage has been observed after 0.2C/cm irradiation.
Track Reconstruction under High Background MC + real background at Belle High pT (Bgp+p-) Low pT (BgD*-(gDps)p+) 100 80 60 Reconstruction eff. (%) 40 20 0 0 5 10 15 20 0 5 10 15 20 Background factor Background factor will be improved by replacing the inner part by Si.
Tentative conclusion • Drift chamber can be used in L=3.51035 at r>15cm. • The detector is designed as an upgrade of Belle detector.
Baseline Design of SuperBelle • Vertexing detector: “striplet” + APV25 or pixel • Central drift chamber: small cell + faster gas • PID device: TOP(B) + Aerogel RICH(E) • EM calorimeter: Pure CsI + tetrode (E) • Scintillator KLM • Pipelined DAQ • Much bigger computing system Issue
Workshop at Shuzenji (Sep. 24-26, 2003) Who? – Open Question • 6 workshops to discuss physics, detector and accelerator issues. • 2001, Aug: 1st workshop at KEK • 2002, Jan (KEK) • 2002, Aug (Shonan) • 2003, Feb (KEK) • 2003, Sep (Shuzenji) • 2004, Nov (KEK) • Letter of Intent for KEK Super B • Factory (KEK Report 2004-4) • Physics at Super B Factory • (hep-ex/0406071) 268 authors • Belle/BaBar joint workshop • 2004, Jan (Hawaii) • 2005, April (Hawaii)
Where? Mt. Tsukuba Tsukuba exp. hall KEKB ring 4e- (HER, 8GeV) + e+ (LER, 3.5GeV) (4s) BB (s 1nb) Lorentz boost bg = 0.425 4Finite angle crossing : 211 mrad Injection Linac
When? - Proposed Schedule J-PARC 1 construction ILC construction Construct. fund T2K SuperKEKB const. Operation fund Crab cavity KEKB machine SuperKEKB KEKB >1000fb-1 “Major” upgrade Belle “Minor” upgrade 2004 05 06 07 08 09 10 11 12 Calendar year
Summary • Why? – Search for new origin of flavor mixing and CP violation • How? – Increase NB, decrease by*, and crab crossing: L=3.51035/cm2/s • What? – New beam pipe, crab cavity, new injector with damping ring. Belle will also be upgraded assuming DC is usable. • Who? – YOU! • Where? – Upgrade existing KEKB. • When? – JFY2009 and 2010 • How much? – US$450M