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Super B factory plan at KEK Masa Yamauchi KEK Super B Factory Workshop April 20-22, 2005 Honolulu Why, how, what, who, when and how much?
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Discovery of CPV in B decays Study of NP effect in B and decays Identification of SUSY breaking mechanism time or integrated luminosity Yes!! sin2 1, CPV in B , 3, V ub, V cb, b s , b s ll, new states etc. Anomalous CPV in b sss NP discovered at LHC(2010?) Now 400 fb -1 if NP=SUSY Why? - Roadmap of B Physics Precise test of SM and search for NP
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Motivations for Super KEKB 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 : 3.8 Polarization in penguin dominated B→VV decays A CP (B ± →K ± 0 ) ≠ A CP (B 0 →K ± ) ± 1. Possible anomalies observed in B decays 2. New physics will be found soon at LHC. 3. e e B factory with L=3.5×10 35 is competitive with LHCb. These MUST be clarified.
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Anomalous CPV hints new physics? - f x S f Belle + BaBar, 2004 top W penguin decay Ave. CPV = 0.41±0.07 Ave. CPV = 0.726±0.037 equal if only SM 3.8 deviation observed Tree decay bc c d s d _ _ _ B J/J/ KSKS W
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Other Evidences for New Physics f L (B→VV) A CP (B→Kπ)
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Comparison with LHCb hep-ex/0406071 SuperKEKB LoI
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Comparison K* (which is Golden mode at LHCb) yield by LHCb is 2.7 times larger than K*ll yield by Super Belle. Need 10 36 machine and better detector(PID, vertex)/analysis. A 7 is fixed to the value obtained from b s LHCb cannot measure B(b s), so they should use our value or float A 7. K*l+l-evts/year S/N A9A9 A 10 A 7 from b s s0s0 LoI Belle (e + ) N.A. 32%44%2.5(exp)+ 2.5(theo)%? 32% Toy Belle (e + ) 1640 1.7 11%13%.2.5(exp)+ 2.5(theo)%? 11% LHCb ( only) 4400 >0.5 6.5%*6.9%*N.A.7.4% If A 7 is fixed. 3 times better *just scaling Belle value with evts. A.Ishikawa 6 th Workshop on Higher Lum. B Factories November 2004
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How? - SuperKEKB Parameters
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Crab Cavity
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Interaction Region Crab crossing =30mrad. y*=3mm New QCS What? – SuperKEKB Design Linac upgrade More RF power Damping ring New Beam pipe Increase beam currents 1.6 A (LER) / 1.2 A (HER) → 9.6 A (LER) / 4.1 A (HER) Smaller y * 6 mm→3 mm Increase y 0.05→0.28(W-S) L=3.5x10 35 cm -2 s -1 8GeV (e+, 4.1A) 3.5GeV (e-, 9.6A)
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Super-KEKB (cont’d) Head-on collision w/ Crab cavity New crab cavity Ante-chamber /solenoid for reduction of electron clouds Circular-chamber Build-up of electron clouds Ante-chamber with solenoid field Will be tested in 2006.
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Fight for Higher Beam Current
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ARES for SuperKEKB
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SCC for SuperKEKB
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KEKB Upgrade Scenario ~10 10 BB/year !! & similar number of + - L peak = 1.4 10 34 cm -2 s -1 L tot = 330fb -1 (Nov.30, 2004) 1.4x10 34 330 fb -1 5x10 34 ~1 ab -1 5x10 35 ~10 ab -1 L peak (cm -2 s - 1 ) L int Crab cavities Major upgrade of KEKB & Belle detector (>1yr shutdown) world records !
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Belle Upgrade SC solenoid 1.5T New readout and computing systems CsI(Tl) 16X 0 pure CsI (endcap) Aerogel Cherenkov counter + TOF counter “TOP” + RICH Si vtx. det. 4 lyr. DSSD 2 pixel/striplet lyrs. + 4 lyr. DSSD Tracking + dE/dx small cell + He/C 2 H 5 remove inner lyrs. Use fast gas / K L detection 14/15 lyr. RPC+Fe tile scintillator
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Q1: Does DC work with L=3.5 10 35 ? If NO, –Need Si tracker. –EM cal, solenoid and iron structure have to be rebuilt!! If YES, –Upgrade the present Belle detector. New detector
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Difference of QCS position is the reason Shower caused by over bend particle Pointed out by M.Sallivan in 6 th HLWS (Nov,2004)
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Rad. Bhabha BG sim. for Super- KEKB FWD EndCap BWD EndCap Barrel L=10 34 /cm 2 /s ~4 % of total BG L=25x10 34 /cm 2 /s Expected BG from other sources with heavy metal total ~ 1.5 ton Realistic design based on discussion with QCS group
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Average Vacuum 5x10 -7 Pa 1 st layer Super-KEKB (current) design
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Does Belle-CDC work with L=3.5 10 35 ? r = 15cm Layer Hit rate/wire(kHz) Exp 27 Run 206 HER 1.1A LER 1.5A L=9.6x10 33 cm -1 s -1 Main Inner Cathode
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Layer Number of hits Bhabha ev. 2000 2002 Layer 49 Layer 1 Layer 3 Radiation damage to the present CDC Efficiency for Bhabha tracks Gain drift No rad. damage has been observed after 0.2C/cm irradiation.
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Track Reconstruction under High Background 51015200 Background factor 51015200 Background factor 0 20 40 60 80 100 Reconstruction eff. (%) High p T ( B ) Low p T ( B D ( D s ) ) will be improved by replacing the inner part by Si. MC + real background at Belle
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Tentative conclusion Drift chamber can be used in L= 3.5 10 35 at r >15cm. The detector is designed as an upgrade of Belle detector.
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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
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Belle/BaBar joint workshop –2004, Jan (Hawaii) –2005, April (Hawaii) 6 workshops to discuss physics, detector and accelerator issues. –2001, Aug: 1 st workshop at KEK –2002, Jan (KEK) –2002, Aug (Shonan) –2003, Feb (KEK) –2003, Sep (Shuzenji) –2004, Nov (KEK) Workshop at Shuzenji (Sep. 24-26, 2003) Who? – Open Question Letter of Intent for KEK Super B Factory (KEK Report 2004-4) Physics at Super B Factory (hep-ex/0406071) Letter of Intent for KEK Super B Factory (KEK Report 2004-4) Physics at Super B Factory (hep-ex/0406071) 268 authors
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Mt. Tsukuba Injection Linac Tsukuba exp. hall KEKB ring e (HER, 8GeV) + e (LER, 3.5GeV) (4s) BB ( 1nb) Lorentz boost = 0.425 Finite angle crossing : 2 11 mrad Where?
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When? - Proposed Schedule 20040506070809101112 KEKB SuperKEKB >1000fb -1 Calendar year Crab cavity KEKB machine SuperKEKB const. J-PARC 1 construction ILC construction Construct. fund “Minor” upgrade “Major” upgrade Belle Operation fund T2K
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How much? - Estimated Cost
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Summary Why? – Search for new origin of flavor mixing and CP violation How? – Increase N B, decrease y *, and crab crossing: L=3.5 10 35 /cm 2 /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
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