Projektbericht BELLE Status BELLE Experiment Die Zukunft von BELLE KEK　高エネルギ, ce^ Tokyo 東京 Collaboration Status BELLE Experiment Die Zukunft von BELLE Neue Resultate (Hot Topics) HEPHY Physik-Analysen

KEKB Collider 156% Design! = 0.425 B-Factory (on the 4s resonance) e- Lpeak=1.56 × 1034cm-2sec-1 design=1034cm-2sec 8GeV 3.5GeV 156% Design! = 0.425 bg B-Factory (on the 4s resonance) BB threshold

~400 million BB pairs KEKB ~256 million BB pairs PEP-II

Belle Detector (2005) 7 sub-detectors for precise Vertexing, Tracking, Particle ID, Calorimetry

Upgrade plan (near future) ECL ・Waveform sampling ・Pure CsI crystal for endcap ・Optimization of the clustering code ・Faster front end electronics ・Faster trigger signal ・Optimization of the tracking code CDC SVD ・Shorter strip/pixel for the inner layers ・Faster readout electronics ・Optimization of the vertex code KLM ・Scintillator tile with SiPM readout DAQ upgrade TDC based readout  pipelined system 　  Dead time free up to 5kHz trigger rate Computing system upgrade CPU, mass storage and network system

SVD Upgrade schedule Direction SUPERBELLE Layer 1 replacement is scheduled in 2007 summer SVD3 schedule depends on approval of the project. 2005 2006 2007 2008 2009 2010 2011 Luminosity (1034) 2.0 3.0 5.0 25 SVD2.0 Reinforcement SVD2.0→SVD2.5 Replace L1 ladders SVD2.5→SVD3 Full upgrade R&D Test Prod. R&D Test Installation Prod. SVD Upgrade schedule

Simulation Study for Higher Beam Background Detail was reported in the last WS by K.Senyo. MC +BGx1 MC+BGx20

Hawai 05 Workshop Interesting proposal by the Vienna group (M.Pernicka) to reduce background induced occupancy in Vertex detector reduction with the possibilities of APV25 and Background reduction using the multi-peak mode One possibility would be to measure the time between trigger and the hits. Thus off-time hits can be discarded. Hits in the selected trigger window are event candidates. The APV25 has the possibility to store 3 consecutive samples (spaced by the system clock) of a signal (multi-peak mode) with one trigger. With a second trigger just 3 clocks later, you can get the next 3 time samples of the shaped input signal. We can use this possibility to determine the time between shaped detector signal and clock. Background reduction using the multi-peak mode Most hits from background events are not correlated (in time) with the trigger (continuous beam). At the moment we have a time window to accept data of >2400 ns for the VA1TA and ~150ns (50ns peaking time) for the APV25. This window of 150ns should be reduced again. Additional reduction of the time window (and thus of the background) by a factor around 8-10! Summary by M. Giorgi

KEKB Collider Upgrade Scenario world records ! ~1010 B mesons/year !! & also t+t- Lpeak = 1.561034cm-2s-1 Ltot = 431fb-1 (May.14, 2005) Major upgrade of KEKB & Belle (>1yr shutdown) SuperKEKB crab cavities Lpeak (cm-2s-1) Lint 1.5x1034 431 fb-1 ~5x1034 ~1 ab-1 ~5x1035 ~10 ab-1

Severe (financial) problems when it is compared with

Scenarios in the next decade We are here Much interesting work has already been done on this topic. Can we find a more effective way to get the message across? LHC turns on LHC finds SUSY LHC doesn’t find SUSY HEP What can a Super B Factory say about SUSY-breaking models? What can the ILC say about SUSY-breaking models?

Pessimistic (?) Conclusions of Hitlin (BaBar Spokesman) What is needed to make the case A credible integrated luminosity capability approaching 10 ab-1/year An accelerator with an upgrade path, as with the current B Factories A detector that is conservatively designed and able to cope with background surprises and future luminosity upgrades A credible plan for gathering a data sample of 10’s of ab-1 that allows the marquee important measurements to be made on a time scale that is competitive with LHCb and relevant to clarifying SUSY discoveries An algorithm that there demonstrates the power of a real-time dialog between the LHC, a Super B Factory and, eventually, the ILC, would be a killer app We have made real progress on this – more is needed Discussions on forming a truly international collaboration on an appropriately scaled accelerator and detector This would, for example, facilitate an ICFA endorsement This could provide a critical mass of people and funding potential to convince the community that a Super B Factory should go forward

ee  J/ψ X, all currently available data (Exp7-41) Neue Resultate – X(3940) ee  J/ψ X, all currently available data (Exp7-41) X(3940) η‘c ηc χc0

B  KX(3872), X  ππJ/ψ, data from Exp7-39 Neue Resultate – X(3872) B  KX(3872), X  ππJ/ψ, data from Exp7-39 ψ(2s) X(3872)

JPC possibilities for X(3872) DD allowed & P-violating unlikely signal for X  γJ/ψ  C=-1 ruled out check of angular distributions  rules out 1±-,0±+,2-- fits of Mππ  2-+ unlikely X(3872) = χc1‘?  unlikely, since mass and BR ratio way off theo. expect.

HEPHY Physik-Analysen Heinz Dibon: Parallelanalyse semileptonische D° Zerfälle Franz Mandl: Studie der inklusive Zerfälle D°  K*X / fX Gerald Richter: Dekohärenz Modelle verschränkter B-Paare Christoph Schwanda: Matrixelemente der HQET Laurenz Widhalm: Formfaktoren semileptonischer D° Zerfälle

Heinz Dibon Parallelanalyse semileptonischer D°-Zerfälle Zweck: Cross-Check der Analysemethode von LW, Quantifizierung von deren Effizienzvorteil Rekonstruktion des Neutrinos gelingt bereits (siehe plot), derzeit wird an der Optimierung der cuts gearbeitet Neutrino Auflösung |ptrue| - |prec| in GeV

e+e-  Inclusive Decays D0  K*0X and D0  0X Franz Mandl Some time ago ( Fig) reported: B (D0  K*X) B (K*  K-+)  6.67%  B (D0  K*X)  10% Method: Full reconstruction of events: tag side + 0, 1, 2 primary mesons e+e-  “right sign” signal side preliminary studies on efficiences etc have been reported (also for D0  0X) all particles “left over” in reconstruction should come from D0 (signal side) ideal method for the determination of inclusive branching ratios for D0  hX, h = K*0, 0, , , ……. (not yet known)

OLD Franz Mandl “some time ago” not in PDG list “some time ago” K-+ effective masses of combinations of charged particles from kinematically selected D0 via recoil, tagging D*+D*-, D*+D*-0 and D*+D*-+- , …. events B(D0  K*X) * B(K*  K-+) = * 3.8% = 6.67% OLD

Franz Mandl M (K) line: e+e-  D*+D*- MC (2 pr) red crosses: e+e-  D*+D*- (0, + -) data (2, 3, 4 pr) arbitrary normalization ok for 3, 4 pr D0  K*0 X (signal) D0  h1X  h2X D0  KX M (K) at least one particle misidentified

QM coherence model investigations beam axis 3.5 GeV e+ 8 GeV e- B0 entanglement region l- l+ K0s π- π+ μ+ full reconstruction side (FR) partial side (PR) example reaction z0 , t0 z1 , t1 z2 , t2 Gerald Richter QM coherence model investigations expected resolutions (PV) cτB0 = 462 μm (LAB) Δm = 0.489 1012 ћs-1 = 0.754 τB0 QM predicted asymmetry + CoMo

QM coherence model investigations Gerald Richter QM coherence model investigations preliminary studies: ML-fit sensitivity for assumed Model and errors Status: preliminary studies finished, fit method delivers sufficient sensitivity

QM coherence model investigations Gerald Richter QM coherence model investigations defining cuts on MC-data to achieve sufficient time resolutions resolutions so far Status: improving primary vertex resolution

Christoph Schwanda

Christoph Schwanda

Christoph Schwanda

Method of „full inclusive reconstruction“ Laurenz Widhalm Method of „full inclusive reconstruction“ additional primary mesons 3.5 GeV e+ e- 8 GeV p K recoil D* D* recoil p p mass- / vertex fit D „inverse“ fit D recoil e/µ p n K p p p

Overview Background Composition Laurenz Widhalm Overview Background Composition ++ D°  pen DATA D°  pmn DATA right sign* right sign* mn² / GeV² mn² / GeV² wrong sign* wrong sign* neutrino invariant mass squared, all cuts applied except neutrino mass cut signal hadronic bkg, misidentified pions non-D° bkg bkg from D°  Kln hadronic bkg, misidentified kaons bkg from D°  K*ln, D°  r*ln

q² distribution – comparison of models pole mass – comp. with CLEO & FOCUS ISGW2 model lattice calc. pole model D0  pln Analyse derzeit in der Refereeing Stage / Präsentation auf Sommer Konferenzen in Vorbereitung

Ereignisrekonstruktion in C++ bei BELLE Ereignisrekonstruktion in C++ bei BELLE PDA Seminar 11/02 Laurenz Widhalm

Baseline design for SUPERBELLE CDC SVD Shoji Uno