Status of Belle Super KEKB plan

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Status of Belle Super KEKB plan. SLAC seminar March 21 st , 2003 Nobu Katayama KEK. Outline. Belle/KEKB status General Beam pipe accident SVD2 Recent physics results Super KEKB plan Physics Detector study Accelerator study. KEKB status 1999/10 - 2003/3/18. - PowerPoint PPT Presentation

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  • Status of BelleSuper KEKB planSLAC seminarMarch 21st, 2003Nobu KatayamaKEK

    Nobu Katayama

  • OutlineBelle/KEKB statusGeneralBeam pipe accidentSVD2Recent physics results Super KEKB planPhysicsDetector studyAccelerator study

    Nobu Katayama

  • KEKB status1999/10-2003/3/18> 50 fb-1 in a year 2002>50 fb-1 in 2002LER>1.55AHER>1A withSRFIP leak: Longest unscheduled shutdown Oct.30~Dec 2002

    Nobu Katayama

  • Best day (03/17/2003)462pb-1/day recordedNK on shift!

    Nobu Katayama

  • Beam pipe accident6AM, Oct. 29, 2003:New record:8.261033 Oct. 30:A vacuum problem happenedOct. 31:A serious problem happenedAfter an abort, HER beam could not be injectedLeak check showed no leakResumed running (vacuum scrubbing)But too much background to the detectorBeam aperture check: something inside?Nov. 1: Opened the vacuum and inspectedNo problem foundNov. 5: Closed the vacuum to resume operationNov. 7: A serious leak occurred and identifiedLeak is from the He cooling line of IR Be beam pipeOct. 29, 2002-Nov. 8, 2002

    Nobu Katayama

  • Structure of IP beam pipe for SVD1.410mm gold by vacuum sputtering 10~30mm gold by chemical plating200~230mm gold by chemical platingInner SurfaceHeBeryllium part is cooled by Helium gas.Aluminum part is cooled by water.:to reduce SR BGto reduce particle background

    Nobu Katayama

  • Pictures using optical fiber scope

    Nobu Katayama

  • Locating the leakAfter dismounting the beam pipe, a leak check was performed to locate the leak pointLeak was confirmed with a bubbling testBubbles were seen on the inner gold sputtered surface of Beryllium beam pipeLeak is not at the joint of Be and AlLeak

    Nobu Katayama

  • Cutting Al part of the beam pipe

    Nobu Katayama

  • Inner Beryllium beam pipeDirection of Helium gas

    position of leak

    Nobu Katayama

  • Location of the leak

    Nobu Katayama

  • ObservationsA large amount of a white powder was found on the outer surface of the inner Beryllium cylinder and on those of Al ringsIt looks like its following the flow of He gasWe found two types of powdersColor of one powder is clearly whiteThe other one looks slightly yellowThickness of the inner Beryllium cylinder was measuredNo significant loss of BerylliumThe beam pipe was used for three months in 1999The powder was there then although the amount was much less

    Nobu Katayama

  • Photo before re-assembly (1999)

    Nobu Katayama

  • Preliminary results of element analysisWhite powderMain components are Be and OProbably, it is BeOYellow powderMain components are Al and OProbably, it is Al2O3 and/or Al(OH)3Commonly found areCarbonSmall amounts of P, K, Ca, S, Cl, Si, Mn, Fe, and Cu were found. S and Cl are dangerous elements for corrosion of BerylliumSi, Mn, Fe and Cu are components of Aluminum alloyBut, expert for element analysis says the amounts of S and Cl are small and are consistent with normal metalNo conclusion, yet

    Nobu Katayama

  • Cause of corrosionCorrosion can occur on the Al and Be surfaces What caused the corrosion is not known yetWater, Cl or S?Radiation?Analysis of circulation gas is in progressBefore the accident, we had not paid attention to corrosionDew point had not been monitored in gas circulating systemWe have never analyzed impurity of the circulating gasCurrently, to avoid corrosionDew point is monitored(~-20C)An additional filter has been installedFresh Helium gas is added more frequently, to avoid accumulation of impurities (Most effective)

    Nobu Katayama

  • Possible causes of Helium leakCorrosion is most suspiciousHeat stress caused by the temperature difference between two wallsResonant HOM heating during machine studyHelium circulation system troublesRecycled Be pipe from BP#1 Large stress at machining process (?)Very high temperature (~300C) When gold was spattered and the Be pipe was welded with Aluminum sectionsDefect of material (?)Still being actively investigated

    Nobu Katayama

  • SEM photos of Be surfaceBeryllium is made by sintering, from a powder of 5~40mm Be particles. Some of them are missing

    Nobu Katayama

  • History of Beam Pipe and SVD19992000200120022003BP 1 + SVD 1BP 2 + SVD 1.2BP 3 + SVD 1.4BP 2 + SVD 1.6Summer 2003BP 4 + SVD 2!BP3 reused BP1 Be pipeSVD 1.4 electronics can survive up to 2M radSVD 1 damagedby back scatteredsynchrotron RadDead wafers replaced

    Nobu Katayama

  • Much better BP4!

    BP#3(1)BP#2BP#4cooling for BeHeHeParaffinAu on Be10mm inside20mm outside10mm insidefwd/bwdAluminumAluminumTantalumAu in fwd200mm inside20mm insidenoAu in bwd20mm inside20mm insidenoRes. HOM5 buckets5 bucketsNo?Saw toothbwdnobwdMaterial (IP)0.6% X00.9% X00.7% X0Particle maskstandardtolerable?better

    Nobu Katayama

  • Daily Luminosity2002/9-2003/3/8Current limit 2.4AOld beam pipere-installedCurrent limit 2.2A

    Nobu Katayama

  • Short term plan3/24~26: Belle general meetingWill discuss beam current limit. LER+HER150 fb-1 in totalIncrease LER current to 2A, then 2.6A and see what happensThis summerInstall SVD2Add last two ARES RF cavities so that HER current can reach 1.2AOperation will start from mid October

    Nobu Katayama

  • SVD 1 SVD 26+12+18+18=54 ladders8+10+14=32 laddersSVD1SVD2RBP 1.5 cmRBP 2.0cmRL13.0cmRL12.0cmRout6.0cmRout8.8cm

    Nobu Katayama

  • How much improved?

    SVD 1.6SVD2.0RBP / RL1 / Rout20/30/60 mm15/20/90 mmAcceptance23

  • Beam pipe for SVD2Smaller radius (1.5cm)

    Better cooling with liquid

    Heavier masks

    Better mechanicalstructures

    Nobu Katayama

  • Ladder construction

    Nobu Katayama

  • Ladder mount completed on 13-Feb. 2003.The last of the 54 ladders!

    Nobu Katayama

  • Track reconstructed!Shibata

    Nobu Katayama

  • Recent physics resultsJust flashingVubBffKBffK*, fK

    Nobu Katayama

  • Fully reconstructed B mesons

    Nobu Katayama

  • Vcb measurement with tag

    Nobu Katayama

  • Vub measurements

    Nobu Katayama

  • Separating two Bs

    Nobu Katayama

  • Two inclusive Vub measurementsTwo new tagging methodsSimulated annealingD*ln reconstructionCan measure Mx distribution

    Nobu Katayama

  • First observation of BffKBr(BffK)=(2.6+1.1-0.90.3)10-6 Mff < 2.85 GeV/c2 to exclude hcOnly penguin (b sssss) can contributeAsymmetry in this decay mode is sensitive to NP due to interference with B hcK, hc ff

    Nobu Katayama

  • BfK* angular analysis

    Nobu Katayama

  • Projected angular distributions

    Nobu Katayama

  • We have just started!More and more BsSuper KEKB

    Nobu Katayama

  • Mission of Super B Factory(ies)Mission 1: 300 fb-1Precision test of KM unitaritySearch for new physics in B and t decaysIdentify SUSY breaking mechanismBreadnd butterfor B factoriesSee quantum effect in penguin and box loopVery important if New physics = SUSYMission 2: 3,000 fb-1Mission 3: 30,000 fb-1

    Nobu Katayama

  • In which processes can we find New Physics?Rare decaysB Xsg ,rgB K*mmCP violationsB fKS and hKSB Xsg rgb c emitting charged HiggsForbidden decays by SMForbidden/rare decays of t

    Nobu Katayama

  • CPV in penguin decaysBelle (July 2002)ACP(fKS)=-0.730.64ACP(hKS)=+0.760.36ACP(J/yKS)=+0.7190.074Expected errors in ACPsACP(fKS, hKS)=ACP(J/yKS)In SM,New phase in penguin loop may change this relationKEKBPEP-IINext B factory

    Nobu Katayama

  • Atmospheric Neutrinos Can Make Beauty Strange?R. Harnik, D. Larson, H. Murayama and A. Pierce (hep-ph/0212180), D. Chang, A. Masiero and H. Murayama (hep-ph/0205111)Leptogenesis models inspired by the nave 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 bs transitions such asAsymmetry in B fKs (effect is in first order)Bs mixingb sg (effect is of the order of |Cg(NP)|2)

    Nobu Katayama

  • Dominant Right-Right Mixing case

    Nobu Katayama

  • SUSY effect in B K*mmThese measurements are excellent probe to search for SUSYInclusive decay, bsll, is much less model dependent. An e+e- B factory provides a unique opportunity to measure this by pseudo reconstruction technique

    A.Alim(mm)2 distributionF/B asymmetrySMSUSY models with various parameters set

    Nobu Katayama

  • Rare decays of t

    Nobu Katayama

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

    Nobu Katayama

  • Comparison with an LHC experimentG(BDtn)/G(BDmn)at B factory with5,000 fb-1B factories dont really do tree diagrams of new particles with the exception of charged Higgs

    Nobu Katayama

  • KEKB upgrade strategyPresent KEKB L=10342002030405080706091011L=1035L~1036dt =500fb-1One year shutdown to: replace vacuum chambers double RF power upgrade inj. linac g C-bandlarger beam currentsmaller by*long bunch optioncrab crossingILER=1.5A2.6AILER=9.4AILER=20AConstraint:8GeV x 3.5GeVwall plug pwr.
  • Detector upgradeHigher luminosity collider will lead to:Higher backgroundradiation damage and occupancy in the vtx. detectorfake hits in the EM calorimeterradiation problem in the tracker and KLm detectorHigher event ratehigher rate trigger, DAQ and computingRequire special features to the detectorlow p m identification for smm reconstruction eff.hermeticity for n reconstruction

    Nobu Katayama

  • m / KL detection 14/15 lyr. RPC+F