time-dependent cp violation in b sqq and b s decays lake louise winter institute feb.21, 2005...
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Time-Dependent CP violation in bsqq and bs decays
Lake Louise Winter Institute
Feb.21, 2005
Yutaka Ushiroda (KEK)
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• Introduction– Time-Dependent CP asymmetry (TCPV)– Belle & KEKB
• Results– TCPV in charmonium modes– TCPV in hadronic bs penguins– TCPV in radiative bs penguin
• Summary
OutlineOutline
b sqqb ccs
b s
0 0
0 0
sin cos
d CP d CP
CP
d CP d CP
B t f B t fA t
B t f B t f
S m t A m t
Time dependent amplitudes are different because of the KM phase
=fcp
B0
B0mixing B0
B0 fcp
Mixing-induced time-dependent CPV
Direct CPV
Time-Dependent CP violation (TCPV)
mixing
V*td
Vtd_ _
t
dt
b
b
d _ww B0B0
__
d
b_ c
c
sd
_wB0J/
K0
b ccs
Mixing (1) + Decay w/o KM phase
In tree, no room that a NP steps in SM anchor point
1sin 2 , 0fS A 1
:f CP eigenvalue
d
b_ _
sssd
_gtB0
K0
, ’...w
V*td
Vtd_ _
t
dt
b
b
d _ww B0B0
_
b sqq
Extra CPV phase (NP)1 1"sin 2 " sin 2 0.73
0b sqq b ccs
A A
_ _
d
b s
ssd
_gbR~_
sR~_
g~
Experimental technique
electron(8GeV)
positron(3.5GeV)
(4S)
+
-
KS
J/B1
B2
+-
K+
-0
D
B0_
B0
t z c
z ~ 200m
fCP
Flavor tag
~1 km in diameter
Mt. Tsukuba
KEKBBelle
KEKB accelerator
3.5 GeV e X 8.0 GeV e
crossing angle = 11 mrad.
34 2 1
1
6
1.5 10
360
# 1 10
peakL cm s
Ldt fb
BB day
Belle
World Records
World Records
Results based on 140fb-1 or 253fb-1
KL detector14/15 layer RPC+Fe
Electromagnetic Calorimeter
CsI(Tl) 16X0
Aerogel Cherenkov Counter n = 1.015~1.030
Si Vertex Detector4-layer DSSD
TOF counter
3.5 GeV e+
Central Drift Chamber momentum, dE/dx 50-layers + He/C2H6
charged particle tracking
K/ separation
K/ separation
B vertexMuon / KL identification
, 0 reconstructione+-, KL identification
8.0 GeV e-
Belle Detector
hep-ex/0408111
4347 signal events
sin21 result
6152 10 BB
poor flavor tag
good flavor tag
qCP=+1qCP=-1
1sin 2 0.728 0.056 0.023
b ccs
Good tag
Poor tag
S = 0.73fit
0
Eve
nts
/(50
MeV
/c) Nsig=3615
purity = 0.17
sig + bkg_sumbkg_sumsig + B-bkgB-bkg
Nsig = 13914purity = 0.63
[hep-ex/0409049]
B0K0
preliminary
~1.9 away
_275M BB
1"sin 2 " 0.06 0.33 0.09
0.08 0.22 0.09A
b sqq
[hep-ex/0409049]
B0KS
~0.0 away
_275M BB
Nsig = 31 7purity = 0.56
Good tagRaw
Asy
mm
etry
10.13"sin 2 " 0.75 0.640.16
0.26 0.48 0.15A
S = 0.73fit
preliminary
b sqq
[hep-ex/0409049]
B0KSKSKS
~2.8 away
_275M BB
Good tagRaw
Asy
mm
etry
1"sin 2 " 1.26 0.68 0.18
0.54 0.34 0.08A
S = 0.73fit
Nsig = Purity =
preliminary
b sqq
[hep-ex/0409049]
B0’KS
~0.4 away
_275M BB
Good tag
Raw
Asy
mm
etry
1"sin 2 " 0.65 0.18 0.04
0.19 0.11 0.05A
S = 0.73fit
Nsig = 512 27purity = 0.61
preliminary
b sqq
[hep-ex/0409049]
B0KKKS
~0.9
_275M BB
Good tagR
aw A
sym
met
ry
1"sin 2 " 0.49 0.18 0.04
0.08 0.12 0.07A
S = 0.73fit
preliminary
Nsig = 399 28purity = 0.56
1 1.03 0.15 0.05f Mixture of CP even/odd
[PRL 91, 261602 (2003)]
b sqq
[hep-ex/0409049]
B0KS0
~0.7
_275M BB
Good tagRaw
Asy
mm
etry
1"sin 2 " 0.30 0.59 0.11
0.12 0.20 0.07A
S = 0.73fit
preliminary
Nsig = (high LHR) (low LHR)purity = 0.55 (high LHR), 0.17 (low LHR)
high LHR only
b sqq
[hep-ex/0409049]
B0f0(980)KS
~2.9
_275M BB
Good tagRaw
Asy
mm
etry
1"sin 2 " 0.47 0.41 0.08
0.39 0.27 0.08A
S = 0.73fit
preliminary
Nsig = 94 14purity = 0.53
b sqq
Deviation from SM expectation !?
w/o theory error
“sin21” from hadronic bs penguins
1"sin 2 ( )" 0.39 0.11b sqq Belle
1sin 2 ( ) 0.726 0.037 . .b ccs W A
~2.7
V*td
Vtd_ _
t
dt
b
b
d _ww B0B0
_
d
b_ _
s
d
tB0 K0
w
b s
Introduction
1
2sin 2 4%s
CPb
mS
m
AGS [Phys.Rev.Lett. 79, 185 (1997)]TCPV in B0M0 decayM0 : self-conjugate state (K*0(KS0), K1(KS0)) : polarized in the SM. Carries the flavor information.
b
b
Ls
Rs
s
b
m
m (Helicity flip)
Due to , the final state is (almost) flavor specific
A large CPV New Physics
An effect that unpolarizes the
~10% according to B.Grinstein, Y.Grossman, Z.Ligeti, D.Pirjol [PRD 71, 011504 (2005)]
Nsig=57 9purity 0.65
S = 0fit
Poor tag
Good tag
0.630.79 0.090.50
0 ( )
S
A fixed
B0K*0(KS0)
[hep-ex/0409049]
preliminary
_275M BB
K2*(1430)
K*(892)
Extended AGS (AGHS)
57 9 105 14
AGHS [hep-ph/0410036]TCPV in B0P0Q0 decayP0,Q0: self-conjugate spin-0 neutral particle (KS0,KS))
Nsig=105 14purity 0.50
S = 0fit
Poor tag
Good tag
0.460.58 0.110.38
0.03 0.34 0.11
S
A
[hep-ex/0410036]prelim
inary
_275M BB
B0KS0
0 1.8SK
M GeV
TCPV in b ccs We know well about SM
TCPV in hadronic b s penguins 2.7 away from SM expectations with all the
Belle results combined
TCPV in radiative b s penguins SM prediction is S~A~0
measured with B0 Ks0 (M(KS0)<1.8GeV) consistent with 0
Summary
0.460.58 0.110.38
0.03 0.34 0.11
S
A
1sin 2 0.728 0.056 0.023
1"sin 2 " 0.39 0.11
_
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