Constraint on CKM angle f 2 from B decays

Constraint on CKM angle Constraint on CKM angle 22

from B decaysfrom B decays

A. Kusaka (University of Tokyo),

on behalf of Belle collaboration

Fourth Workshop onMass Origin and Supersymmetry PhysicsMar. 6-8, 2006, Tsukuba, Japan

New “phase” of B factoriesNew “phase” of B factoriesConfirmation of KM model of CPV

sin21 by J/K0, etc… 2

3

Vub, etc…

Search for the physics beyond SM = New “phase” from new physics

Rare decaysConsistency check (Unitarity Triangle closur

e)

So, why So, why 22 ? ?

Essential to check the Unitarity Triangle closure

Fundamental parameter of KM model

ContentsContentsPrincipleCP violation measurement

CPV measurement of B0+–

CPV measurement of B0+–

Isospin analysis Penguin pollution Isospin analysis

Dalitz-t analysis with B

B0

b–

d du–

d–u

/

/

CKM triangle and CKM triangle and 22

13

2VudV*ub

VtdV*tb

VcdV*cb

B0

d

b–

d–

bt

–tB0

–Vtb V*

td

V*tbVtd

V*ud

Vub

Mixing diagram Decay diagram (tree)

CKM triangle and CKM triangle and 22

B0

b–

d du–

d–u

/

/V*ud

Vub

B0

B0

B0

CP violation measurementCP violation measurement

BB00: Event selection: Event selectionEvent reconstruction

PID (K/ separation)Continuum suppression (modified SFW,

flavor tagging information)

2*2Bbeambc pEM

beamB EEE *

e+e–B

B

e+e–

q

q

CPV measurement of BCPV measurement of B00++––

S = 0.67 0.160.06

4 evidence of Direct CPV!

Published as PRL 95, 101801

High Quality region

MBC (GeV) E (GeV)

Nu

mb

er

of e

vent

sA = +0.56 0.120.06

good tag

66643 events used

BB00: Belle vs. BaBar: Belle vs. BaBar

B0 tagged

B0 tagged–

PRL 95, 151803

S = 0.30 0.170.03A = +0.09 0.150.04

S

A

2.3 discrepancybetween Belle and BaBar

Belle 275MBB

BaBar 227MBB

CPV measurement of BCPV measurement of B00++––

Differences from B0+–

Good point Small branching fraction of B000 (<1/20)

compared with B0and B+small penguin pollution

Bad (difficult) points Decay product contains two 0

lower efficiency, larger BG Consists of three polarization states

polarization measurement is essential

BB00: Event selection: Event selectionThe same technique as

B0

E, Mbc

PIDSFW + tagging info.

The information of mass is also used.

0.62<M<0.92 (GeV/c2)

M (GeV)

Nu

mb

er

of e

vent

s

Good tag

MBC (GeV) E (GeV)

Nu

mb

er

of e

vent

s

PolarizationPolarizationB0+– has 3 polarization states with diffe

rent CP eigenvalues

Longitudinal Transverse

cos

0.030 9510 03300390

..L .f

Belle preliminary

# of

Eve

nts

Fortunately, longitudinal polarization is dominant.

Time dependent fitTime dependent fit

q=+1 q=1

poor tag good tag

08.041.0 08.0

0.08 30.0 00.0

L

L

S

ABelle preliminary

No CP violation

22eff ~ 180 (deg.)

hep-ex/060102419432 events used

BB00: Belle vs. BaBar: Belle vs. BaBar

PRL 95, 041805

08.014.0 24.0 33.0

0.09 18.0 03.0

L

L

S

A

S

A

Belle 275MBB

BaBar 232MBB

Consistent with each other

Isospin analysisIsospin analysis

Penguin pollutionPenguin pollution

B0

d

b–

d–

bt

–tB0

–Vtb V*

td

V*tbVtd

Mixing diagram

+ 2B0

b–

du–

d–

/

/V*ud

Vub

Tree diagram

d

u

)2sin( 2S

0A

Penguin pollutionPenguin pollution

B0

d

b–

d–

bt

–tB0

–Vtb V*

td

V*tbVtd

Mixing diagram

+

Penguin diagram

B0

d

b–

t–

d–

u

u–

d/

/Vtb V*

td

0+

)2sin(1 eff2

2 AS

2eff2 22

2B0

b–

du–

d–

/

/V*ud

Vub

Tree diagram

d

u

Isospin analysis (how to get Isospin analysis (how to get ))

2eff22

)( 00 BAΑ

)( 00000 BAΑ

)( 0 BAΑ

0002 AAΑ 0A

00A2A

• BF and asymmetries: World average (HFAG)• Ahh and Shh: Belle measurement above.

Situation of BSituation of B

2eff22

Due to the large A,one of the triangles aresqueezed.

excluded at 90% C.L.

at 1Belle

Situation of BSituation of B

excluded at 90% C.L.

at 1Belle

excluded at 90% C.L.

BaBar

Situation of BSituation of B

at 90% C.L.

at 1

Due to the small Br ofB000, both of twotriangles are squeezed.

Good determination of 2

(with only two mirror solutions)

2eff22

Belle

Situation of BSituation of B

at 90% C.L.

at 1

Belle

at 90% C.L.

at 1

BaBar

Dalitz-Dalitz-t analysis with Bt analysis with B00

Dalitz-Dalitz-t analysis with t analysis with BB00 Dalitz Plot Final sta

tes can be resolved

, , , +interferences.

Measure their time dependence.

Sufficient information to determine all the amplitudes, including strong phase .

hep-ex/0408099

s+=m2()

s =

m2(

)

2

6 113 27172

BaBar preliminary

Snyder & Quinn, 1993

Combined resultsCombined results

Combined resultsCombined results

at 90% C.L.

at 1Belle

Combined resultsCombined results

at 90% C.L.

at 1Belle

at 1BaBar

Combined resultsCombined results

at 90% C.L.

at 1Belle

CKM (indirect)

All W.A.

22 W.A. W.A.

Summary and prospectsSummary and prospectsCKM angle 2 is measured with B, ,

and .Combining B and B from Belle,

we constrain 2=93+12-11 for 1.The value from direct measurements is con

sistent with that from indirect measurements.

With increased data set and modes, we will soon obtain the result with much better precision.

SU(3) expectation on SU(3) expectation on AA and and AAKK

Expectation by theory A ~ AK/3

N. G. Deshpande, and X.-G. He, Phys. Rev. Lett. 75, 1703-1706 (1995), hep-ph/9412393.

Gronau, and J. L. Rosner, Phys. Lett. B595, 339-346 (2004), hep-ph/0405173.

Measurements by experiment A = +0.56 0.120.06 (Belle)

A = +0.09 0.150.04 (BaBar)

AK = 0.113 0.0220.008 (Belle)

AK = 0.133 0.0300.009 (BaBar)

B.F. used for Isospin analysisB.F. used for Isospin analysisBr() fL() = 25.6 +- 6.5Br() fL() = 24.4 +- 3.7Br() = 0.54+0.407-0.372Asym() = N/A

Br() = 5.5 +- 0.6Br() = 4.6 +- 0.4Br() = 1.51 +- 0.28Asym() = 0.28 +- 039

chi2 of isospin analysischi2 of isospin analysischi2 of isospin analysis.

: 0.35 : 0.60 combined: 1.15

Comparison with BaBarComparison with BaBar

08.042.0 09.0

30.0 00.0 10.009.0

L

L

S

A

06.016.0 67.0

0.0612.0 56.0

S

A

03.017.0 30.0

0.0415.0 09.0

S

A

09.018.0 03.0

24.0 33.0 08.014.0

L

L

S

A

Belle 275M BB

BaBar 227M BB 232M BB

Results are consistent with each other.

Difference from Belle is 2.3

Data usedData used253/fb

253/fb (275M BB) until 2004 summer is used.–