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?

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

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.

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

Other Evidences for New Physics f L (B→VV) A CP (B→Kπ)

Comparison with LHCb hep-ex/ SuperKEKB LoI

Comparison  K* (which is Golden mode at LHCb) yield by LHCb is 2.7 times larger than K*ll yield by Super Belle. Need 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 A9A9 A 10 A 7 from b  s s0s0 LoI Belle (e + ) N.A. 32%44%2.5(exp)+ 2.5(theo)%? 32% Toy Belle (e + ) %13%.2.5(exp)+ 2.5(theo)%? 11% LHCb ( only) 4400 > %*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

How? - SuperKEKB Parameters

Crab Cavity

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)

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.

Fight for Higher Beam Current

ARES for SuperKEKB

SCC for SuperKEKB

KEKB Upgrade Scenario ~10 10 BB/year !! & similar number of  +  - L peak = 1.4  cm -2 s -1 L tot = 330fb -1 (Nov.30, 2004) 1.4x 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 !

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

Q1: Does DC work with L=3.5  ? 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 6 th HLWS (Nov,2004)

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

Average Vacuum 5x10 -7 Pa 1 st layer Super-KEKB (current) design

Does Belle-CDC work with L=3.5  ? 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

Layer Number of hits Bhabha ev 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.

Track Reconstruction under High Background Background factor Background factor 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

Tentative conclusion Drift chamber can be used in L= 3.5  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

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 , 2003) Who? – Open Question Letter of Intent for KEK Super B Factory (KEK Report ) Physics at Super B Factory (hep-ex/ ) Letter of Intent for KEK Super B Factory (KEK Report ) Physics at Super B Factory (hep-ex/ ) 268 authors

Mt. Tsukuba Injection Linac Tsukuba exp. hall KEKB ring  e  (HER, 8GeV) + e  (LER, 3.5GeV)   (4s)  BB (   1nb)  Lorentz boost  =  Finite angle crossing : 2  11 mrad Where?

When? - Proposed Schedule 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

How much? - Estimated Cost

Summary Why? – Search for new origin of flavor mixing and CP violation How? – Increase N B, decrease  y *, and crab crossing: L=3.5  /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