2. 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

3. 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

4. ~400 million
BB pairs
KEKB
~256 million
BB pairs
PEP-II

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

6. 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

7. 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

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

9. 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

10. 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

11. Severe (financial) problems when it is compared with

12. 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?

13. 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

14. 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

15. 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)

16. 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.

17. 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

18. 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

19. 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)

20. 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

21. 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

22. 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 = ћs-1 = τB0
QM predicted asymmetry + CoMo

23. 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

24. 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

25. Christoph Schwanda

26. Christoph Schwanda

27. Christoph Schwanda

28. 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

29. 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

30. 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

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

32. Baseline design for SUPERBELLE
CDC
SVD
Shoji Uno