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


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


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 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


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


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


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


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


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


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


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


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)


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


Spares


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


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


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)

Qq

Qq

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


Next: 2(α) from Bfcp>=+

Vtb

B0

B0

V*

V*

td

td

Vtb

Vub

Vub

+

+

B0

+ V*2 V2

td ub


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　


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the belle experiment recfa meeting 2004 / innsbruck -3]mc 32by[k

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bd cp

d s b u v ud v

c d ata d

j ksks b b b

ratio f b f d

v td v cb

v ud v cb

v cd v tb