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.–
