The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
KEK 高エネルギ , ce^Tokyo 東京
The BELLE Experiment
• The Experiment
• The Physics
• Overview of Newest Results
Collaboration
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Lpeak=1.2 x1034cm-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
BBthreshold
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
SVD
The BELLE Detector
Difference SVD1.6 and SVD2.0
6+12+18+18=54 Ladders
8+10+14=32 Ladders
SVD1 SVD2
Rbeampipe 15 mmRbeampipe
20 mm
Rlayer 1
30 mm
Rlayer 1
20 mm
Routside
60 mm
Routside
88 mm
R-Z Trigger
R-PHI Trigger 2 x 18 FADCTF
Trigger outputs
L1.5 Trigger outputs
24 input OR and analog signal input from VATA
Fast connection to PCI bus
Multi event buffer
Vienna R/O & Trigger Electronics
● KVFKVF tends to use more bad measurements, and also use less good
measurements
● DAFDAF uses more measurements in total, moderately weighted
rightlyrejected
rightlyaccepted
falselyrejected
falselyaccepted
association weight association weight
Deterministic annealing filtersfor robust vertexing in BELLE
performance overviewtag-side reconstruction (MC)
● initial KVF fit, cut on χ² prob < 1%● histogram range: [- 600; +600] µm
KVFBIP type: (none) 1 2preFitTrkC2pCut: 0 0 0.05 %K0s cut: no no YES
119,4 128,1 115,5variance 1,58 1,61 1,59# events: 5678 6306 5289 DAFBIP type: (none) 1 2preFitTrkC2pCut: 0 0 0.05%K0s cut: no no YES
124,4 111,5 107,7variance 1,56 1,34 1,43# events: 6360 6903 5677
dz [µm]
dz [µm]
best resolution of DAFDAF:● 107.7 ± 1.43 µmbest resolution of KVFKVF:● 115.5 ± 1.59 µm
DAF DAF resolution at its highest eff.:● 111.5 ± 1.34 µm @ 6903
KVF KVF resolution at its highest eff.:::● 128.1 ± 1.61 µm @ 6306
Efficiency gain of appox. 6 – 16%Precision gain between:
16.6 ± 2.09 µm and 4 ± 2.08 µm
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
The Physics of BELLE
self-consistent if SM correct
Vtb*Vtd
Vcb*Vcd
unitarity triangle
Vub*Vud
Vcb*Vcd
Vtb*Vtd
Vcb*Vcd
+ 1 + = 0
i i
{i=1,k=3}: Vub*Vud+Vcb*Vcd+Vtb*Vtd = 0 d s bu Vud Vus Vub
c Vcd Vcs Vcb
t Vtd Vts Vtb
CKM-Matrix
1
i
0
BB00->ππ->ππBB00->->ππ
BB00->J/->J/KKss
BB00->->KKss
BB00->D->D((**) ) DD((**))BB00-> D*π-> D*πBB00->D*->D*B->DB->DCPCPKK
Vub*Vud
Vcb*Vcd
1
2
3
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Principle of 1-Measurement with B J/Ks
t z/(cβγ)
Flavor-tag decay(B0 or B0 ?)
J/
KS
B - B
B + B
ee
more B’s
more B’s
zt=0
fCP
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
sin21 (Belle 2003, 140 fb-
1) =0.733±0.057±0.028
sin21 (BaBar 2002, 81 fb-
1) =0.741±0.067±0.033
• collected 200/fb integrated luminosity until March 2004• corresponding to 190 millionen B-events
Overview of New Results
CP = +1 sample
sin21 = 0.80±0.13
CP = -1 sample
sin21 = 0.73±0.06
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
New Physics in B Ks ?• B Ks theoretically clean• A = -0.15 ± 0.29 ± 0.07• sin21eff = –0.96 ± 0.50• 3,5 deviation from precision result!
SM predicts same CPV in b ccs and sqq.
SM predicts same CPV in b ccs and sqq.
New physics may deviate CPV in b ccs from sqq New physics may deviate CPV in b ccs from sqq
+
SM penguinSM penguin
Hint of new physics
New process w/ different CP phaseNew process w/ different CP phase
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
B0 KS B0 KKKS B0 ’KS
fS
A
09.011.050.096.0
07.029.015.0
18.000.005.026.051.0
04.016.017.0
05.027.043.0
04.016.001.0
B fCP(sqq) decay vertices are reconstructed using K- or -track pair.
Fit sin21
@ 152M BBComparison of several channels
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
New Charmonium Resonance ?
• found in channel B± K±(J/ )• mass: 3871.8±0.7±0.4 MeV• natural width < 3.5 MeV @ 90% C.L.• 34.4±6.5 events, statist. significance 8.6
(2S)
M(J/ ) - M(J/ ) GeV
Belle304M B’s
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Vienna Analysis - Motivation
• |Vub| can be measured in B l
• requires knowledge of form factor fB(q2)
• analoguous form factor fD(q2) can be measured in D l • ratio fB /fD is theoretically betterknown than absolute value reduction of theoretical error
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -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
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Overview of Vienna Charm AnalysesWhat we are going to do with the data:
• semileptonic form factors- f+
D (q²) for D l
- may be used to reduce systematicerror on f+
B (q²) for |Vub| measurement
- high resolution q² distribution for D l
• cross sections for D*D*(n)- various channels: D*D*, D*D*,
D*D*KK, D*D*, D*D*, D*D*KK
• inclusive D decays BR
- various channels, mostly poorly measured:
- D K± + anything
- D e± + anything
- D µ± + anything
- D + anything
Kl
l
m² / GeV²
m² / GeV²
REAL DATA
reconstructed neutrino mass
Statistics after bkg subtraction:
• D Kl417 ± 20 events (4.8%stat
1.1%bkgsyst)
• D l45 ± 6 events (12.8%stat
5.4%bkgsyst)
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
l Analysis: q² distribution K/l Analysis
• shapes of bkg derived from MC except for non-D bkg (from D* side-band data)
• bkg subtracted according to bkg measurement presented before
• efficiency correction slightly rising with q² for K, rather flat for
our advantage: comparatively clean, high resolution sample
corrected q² distribution
q² / GeV²
q² signal & background
Kl
l
REAL DATA
MC DATA
Dl
non-D bkg
Dl
D hadronicform factor f+(q²)
single-pole model
single-pole model
arbitrary normalization
q² / GeV²
q² / GeV²
Kl
l
REAL DATA
preliminarypreliminary
preliminarypreliminary
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[kEreignisrekonstruktion in C++ bei BELLE PDA Seminar 11/02 Laurenz Widhalm
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Spares
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Prinzip der 1-Messung mittels B J/Ks
• keine theoretische Unsicherheit• experimentell sauber• „goldener Kanal“
B0
B0 B0
Vcb
VtbV*
V*Vtb
V*2
td
td
td
J/
J/
KS
KS
Vcb
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Neue Physik in B Ks ?
Erst die Zukunft, mit mehr Statistik (und eventuell weiter verbesserter Analyse) wird die Antwort bringen!
70 ± 9 events
• BaBar Resultat von 2002: sin21eff = –0.18 ± 0.52• Resultat 2003: sin21eff = +0.45 ± 0.44• Grund für Verschiebung ist eine 1 statistische Fluktuation
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Neue Charmonium Resonanz ? Interpretation:• Masse gerade an der D0D*0 threshold• lose gebundenes “molecular charmonium”, oder ein (13D2) Zustand?
“Discovery of the signal is very recent. Belle is working on this channel but is not ready to present any results” (Lepton-Photon 2003)
Ersteres in der Literatur diskutiert seit 1975:– ausgelöst durch komplizierte Struktur von (e+e- ->hadrons) bei SPEAR
• M. Bander, G.L. Shaw, P. Thomas, PRL 36, 695 (1976)• M.B. Voloshin, L.B. Okun JETP Lett. 23, (1976), Pisma Zh.Eksp.Teor.Fiz.23, 369 (1976) • A.De Rujula, H.Georgi, S.L.Glashow, PRL 38 (1977)
– WW beschrieben durch -Austausch gibt attraktive Kraft für DD*, BB*• N.A. Tornqvist, PRL 67, 556 (1991), Z.Phys. C61, 525(1994)
• A.V. Manohar, M.B. Wise,Nucl.Phys. B339, 17(1993)
D0D*0
molecule
DiquarkModel
(Qq) are colored
Loose binding
A different ideafrom that time:
Decays to (QQ)+(light mesons) via quarkrearrangement which suppresses the width.
Stronger binding
Q Qq q
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Next: 2(α) from Bfcp>=+
Vtb
B0
B0
V*
V*
td
td
Vtb
Vub
Vub
+
+
B0
+ V*2 V2
td ub
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
Constraints on the CKM angle φ2 (α)• • SSππππ, A, Aππππ depend on 4 parameters: depend on 4 parameters:22, , 11[21.3°-25.9°][21.3°-25.9°], |P/T|, |P/T|[0.15-0.45][0.15-0.45], , -> plot confidence contours in (-> plot confidence contours in (22, , ) for various |P/T|) for various |P/T| e.g.e.g.
|P/T|=0.3|P/T|=0.311 =23.5° =23.5°
22
Indirect constraints (CKM fitter group):78.3°≤ 78.3°≤ 22 ≤ 121.6° ≤ 121.6° (95% C.L.) consistent
Find:Find:78°≤ 78°≤ 22 ≤ 152° ≤ 152° (95% C.L.)insensitive to
The BELLE Experiment RECFA Meeting 2004 / Innsbruck -3]mc 32by[k
office of a Japanese physicist (complete with camping bed)
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