projektbericht belle vorstandssitzung 19. mai 2005 -3]mc 32by[k
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Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
KEK 高エネルギ , ce^Tokyo 東京
Projektbericht BELLE
• Status BELLE Experiment
• Die Zukunft von BELLE
• Neue Resultate (Hot Topics)
Collaboration
• HEPHY Physik-Analysen
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Lpeak=1.56 × 1034cm-2sec-1
design=1034cm-2sec
KEKB Collider
e-
8GeV
e+
3.5GeV
= 0.425
B-Factory(on the 4s resonance)
B-Factory(on the 4s resonance)
BBthreshold
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
~400 millionBB pairs
KEKB
PEP-II
~256 millionBB pairs
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Belle Detector (2005)
• 7 sub-detectors for precise – Vertexing, – Tracking, – Particle ID, – Calorimetry
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Upgrade plan (near future)Upgrade plan (near future)
CDC
・ Faster front end electronics・ Faster trigger signal・ Optimization of the tracking code
KLM
・ Scintillator tile with SiPM readout
ECL
・ Waveform sampling・ Pure CsI crystal for endcap・ Optimization of the clustering code
SVD・ Shorter strip/pixel for the inner layers・ Faster readout electronics・ Optimization of the vertex code
DAQ upgradeTDC based readout pipelined system Dead time free up to 5kHz trigger rateComputing system upgradeCPU, mass storage and network system
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Layer 1 replacement is scheduled in 2007 summerSVD3 schedule depends on approval of the project.
2005 2006 2007 2008 2009 2010 2011
Luminosity (1034) 2.0 3.0 5.0 5.0 0 0 25
SVD2.0 Reinforcement
SVD2.0→SVD2.5 Replace L1 ladders
SVD2.5→SVD3 Full upgrade
R&D
Prod.
TestProd.
Test
R&D Installation
Direction SUPERBELLE
SVD Upgrade schedule
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Simulation Study for Higher Beam Background
Detail was reported in the last WS by K.Senyo.
MC +BGx1 MC+BGx20
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
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 modeMost 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!
Interesting proposal by the Vienna group (M.Pernicka) to reduce background induced occupancy in Vertex detector reduction with the possibilities of APV25 andBackground reduction using the multi-peak mode
Hawai 05 Workshop
Summary by M. Giorgi
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
KEKB Collider Upgrade Scenario
~1010 B mesons/year !!
& also +-
Lpeak = 1.561034cm-2s-1
Ltot = 431fb-1 (May.14, 2005)
crabcavities
Major upgrade ofKEKB & Belle(>1yr shutdown)
world records !
1.5x1034
431 fb-1
~5x1034
~1 ab-1
~5x1035
~10 ab-1
Lpeak (cm-2s-1)Lint
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Severe (financial) problems when it is compared with
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Scenarios in the next decade
LHC finds SUSY
LHCturns on
LHC doesn’tfind SUSY
We are here
HEP
What canthe ILC say about
SUSY-breaking models?
What can a Super B Factory say aboutSUSY-breaking models?
Much interesting workhas already been doneon this topic.Can we find a more effective way to getthe message across?
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
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 backgroundsurprises 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
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Neue Resultate – X(3940)
ee J/ψ X, all currently available data (Exp7-41)
ηc
η‘c
χc0
X(3940)
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Neue Resultate – X(3872)
B KX(3872), X ππJ/ψ, data from Exp7-39
X(3872)
ψ(2s)
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
JPC possibilities for X(3872)• J ≤ 2• 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.
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
HEPHY Physik-Analysen
Heinz Dibon: Parallelanalyse semileptonische D° Zerfälle Franz Mandl: Studie der inklusive Zerfälle D° K*X / X Gerald Richter: Dekohärenz Modelle verschränkter B-Paare Christoph Schwanda: Matrixelemente der HQET Laurenz Widhalm: Formfaktoren semileptonischer D° Zerfälle
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
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
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Franz Mandl
Inclusive Decays D0 K*0X and D0 0X Some time ago ( Fig)
reported:
B (D0 K*X) B (K* K-+) 6.67%
B (D0 K*X) 10%
Method: Full reconstruction of events:
D * D 0
K X+ 0, 1, 2 primary mesons
D * D 0
K
K 0
tag side signal side“right sign”
e+e-
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)
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
“some time ago”
B(D0 K*X) * B(K* K-+) = * 3.8% = 6.67%
125.971.7
K-+ effective masses of combinations of charged particles from kinematically selected D0 via recoil, tagging D*+D*-, D*+D*-0 and D*+D*-+- , …. events
not in PDG list
OLD
Franz Mandl
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
line: e+e D*+D* MC (2 pr)
red crosses: e+e D*+D* (0, data (2, 3, 4 pr)
D0 K*0 X (signal)
D0 KXD0 h1X
h2X
at least one particle misidentifiedM (K)
arbitrary normalization
ok for 3, 4 pr
Franz Mandl
QM coherence model investigations
● cτB0
= 462 μm (LAB)
● Δm = 0.489 1012 ћs-1 = 0.754 τ
B0
beam axis3.5 GeV e+8 GeV e-
B0
B 0interaction point
(IP) = primary vertex
decay point 1 =
secondary vertex
B0entanglement
region
entanglementregion
l-
decay point 2 =
secondary vertex
l+
K0s π-
π +
μ+
full reconstruction
side (FR)
partial reconstruction
side (PR)
example reaction
example reaction
z0 , t
0z
1 , t
1
z2 , t
2
full 50 0,2partial 120 0,5
zlab
tCMS [
B]
expected resolutions
expected resolutions
QM predicted asymmetry + CoMoQM predicted asymmetry + CoMo
(PV)
Gerald Richter
QM coherence model investigations
preliminary studies:ML-fit sensitivity for assumed Model and
errors
preliminary studies:ML-fit sensitivity for assumed Model and
errors
Status:preliminary studies finished, fit method delivers sufficient sensitivity
Gerald Richter
QM coherence model investigations
defining cuts on MC-data to achieve sufficient time
resolutions
defining cuts on MC-data to achieve sufficient time
resolutions
Status:improving primary vertex resolution full 70 0,28
partial 90 0,36PrimVtx 450 1,8
zlab
tCMS [
B]
resolutionsso far
resolutionsso far
Gerald Richter
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
K
D
D*
mass- / vertex fit
e+ e-3.5 GeV 8 GeV
K
KD*
D
e/µ
Method of „full inclusive reconstruction“
„inverse“ fit
additional primarymesons
Laurenz Widhalm
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
Overview Background Composition
neutrino invariant mass squared, all cuts applied except neutrino mass cutneutrino invariant mass squared, all cuts applied except neutrino mass cut
right sign*
wrong sign*
right sign*
wrong sign*
m² / GeV² m² / GeV²
signal
non-D° bkg
hadronic bkg, misidentified kaons
hadronic bkg, misidentified pions
bkg from D° Kl
bkg from D° K*lD° *l
++ D° eD° e D° D° DATA DATA
Laurenz Widhalm
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[k
q² distribution – comparison of models
ISGW2 model
lattice calc.
pole model
• Analyse derzeit in der Refereeing Stage / Präsentation auf Sommer Konferenzen in Vorbereitung
pole mass – comp. with CLEO & FOCUS
D0 lD0 l
Projektbericht BELLE Vorstandssitzung 19. Mai 2005 -3]mc 32by[kEreignisrekonstruktion in C++ bei BELLE PDA Seminar 11/02 Laurenz Widhalm
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