1 disclaimer this talk is not for b physics experts. taipei101 if you did it, you may check e-mails...
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1
DisclaimerDisclaimer • This talk is not for B physics experts.
Taipei101
If you did it, you may check e-mails during my talk.
B0
B0
22 ( ( and and 33 ( ())
Masashi Hazumi (KEK)
3rd International Conference on Flavor Physics (ICFP2005), October 3-8, 2005
1 “beam”1 “beam”
2 “banana”2 “banana”
3 “fan”3 “fan”
3
Motivation for Motivation for 22 and and 33 measurements measurements
• Overconstrain the CKM unitarity triangle– important test of Kobayashi-Maskawa mechanism of CP violation– one of the main physics goals of BaBar and Belle
• Overconstrain the CKM unitarity triangle– important test of Kobayashi-Maskawa mechanism of CP violation– one of the main physics goals of BaBar and Belle
1 “beam”1 “beam”
2 “banana”2 “banana”
3 “fan”3 “fan”
4
Principle of measurementPrinciple of measurement
• 2 from time-dependent CP asymmetries
• 3 from direct CP asymmetries
1 “beam”1 “beam”
2 “banana”2 “banana”
3 “fan”3 “fan”
(other methods exist but are not competitive)
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MethodsMethods
• Interestingly, at present best results on 2 and 3 are obtained by methods proposed after B factories started taking data.
• Interestingly, at present best results on 2 and 3 are obtained by methods proposed after B factories started taking data.
• In reality, you need• two diagrams with different weak phases (CP-odd phases) and strong
phases (CP-even phases)
• two amplitudes with similar size ( |A1/A2| = r > O(0.1) )
• precise measurements (knowledge) on and r
• sufficient signal yields with good (tolerable) background level
A1/A2=|A1/A2|exp(i)exp(i) CP |A1/A2|exp(i)exp(i) A1/A2=|A1/A2|exp(i)exp(i) CP |A1/A2|exp(i)exp(i)
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Mixing-induced CP violation (CPV) and Mixing-induced CP violation (CPV) and 2 2 (())
13
2VudV*ub
VtdV*tb
VcdV*cb
B0
d
b–
d–
bt
–tB0
–V*
tb Vtd
V*tbVtd
Mixing diagram Decay diagram (tree)
B0
b–
d du–
d–u
/
/Vud
V*ub
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Mixing-induced CP violation (CPV) and Mixing-induced CP violation (CPV) and 2 2 (())
B0
B0 (
B0
E (GeV)Events/(0.02GeV)
666±43 signals from275 million BB pairs
Small |Vub| = (4.38 0.19 0.27 ) 10
3
measurements still limited by statistics
B0
b–
d du–
d–u
/
/Vud
V*ub
8
Mixing-induced CP violation (CPV) and Mixing-induced CP violation (CPV) and 2 2 (())
B0
B0 (
B0
Small |Vub| = (4.38 0.19 0.27 ) 10
3
measurements still limited by statistics
617±52 signals from232 million BB pairs
signal-enhancedregion
B0
b–
d du–
d–u
/
/Vud
V*ub
9
made by H. Miyake
Time-dependent CP violation in BTime-dependent CP violation in B00
(A = C )
(CP = +1)
Mixing-induced CPVMixing-induced CPV Direct CPVDirect CPV
With the tree diagram only
S = sin22
A = 0
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Tough (Tough () bananas: penguin pollution) bananas: penguin pollution
• Compelling evidence for direct CPV
• Large penguin diagram (P) ~ Tree diagram (T)
• Large strong phase difference between P and T
B0d
d
b
du
u
W
g +
-
VtdV*
tb
t d
A
S
4.0direct CPV4.0direct CPV
2222 )2sin(1 effeffAS 2222 )2sin(1 effeffAS
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Isospin analysis: flavor SU(2) symmetryIsospin analysis: flavor SU(2) symmetry
• Model-independent (symmetry-dependent) method• SU(2) breaking effect well below present statistical errors
2222 )2sin(1 effeffAS 2222 )2sin(1 effeffAS
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22 ( () from B ) from B
inputsB(+0) = (5.5 0.6)B(+-) = (5.0 0.4) 10-6
B(00) = (1.5 0.3) A(00) = +0.28 0.4S(+-) = 0.50 0.12A(+-) = +0.37 0.10
inputsB(+0) = (5.5 0.6)B(+-) = (5.0 0.4) 10-6
B(00) = (1.5 0.3) A(00) = +0.28 0.4S(+-) = 0.50 0.12A(+-) = +0.37 0.10
larger than expected big impact on 2 determinationlarger than expected big impact on 2 determination
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Isospin analysis with BIsospin analysis with B00
• Even worse on first sight ...– Dirty final state: – Mixture of CP = +1 and 1: need to know each fraction
(A++A-)/√2
A||
(A+-A-)/√2
A⊥
A0
+
+A0
A+
A-
+1
1
1
CP
vector vector
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BB00 longitudinal polarization from helicity distributionlongitudinal polarization from helicity distribution
total background
fL= 0.951 0.0290.031
0.0330.039 fL= 0.978 0.0140.020
0.028
CP(A++A-)/√2
A||
(A+-A-)/√2
A⊥
A0
+
+A0
A+
A-
+1
1
1
~purelyCP = +1 !~purelyCP = +1 !
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22 ( () from B ) from B
2A00
A+-/ 2
squashed triangle small
Inputs to isospin analysisB(+0) = (26 6)B(+-) = (26 4) 10-6
B(00) < 1.1 A(00) = N.A.S(+-) = 0.22 0.22A(+-) = 0.02 0.17
Inputs to isospin analysisB(+0) = (26 6)B(+-) = (26 4) 10-6
B(00) < 1.1 A(00) = N.A.S(+-) = 0.22 0.22A(+-) = 0.02 0.17
the best mode now !the best mode now !
2 = (96 13)º 2 = (96 13)º
(triangle not closed with present central values)
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Time-dependent Dalitz analysis with BTime-dependent Dalitz analysis with B00
• ArE to try even more involved analysis
s =
m(
)
2
s+=m()2
+
+
+
Isospin analysis isolate penguin and restore the simplicityDalitz analysis accept complication and dare to utilize Breit-Wigner phasesIsospin analysis isolate penguin and restore the simplicityDalitz analysis accept complication and dare to utilize Breit-Wigner phases
is for strong/CP-even phase difference. Breit-Wigner phases from .
Amplitudes should be large enough for good statistics. similar to
ratios between amplitudes
Determined by Dalitz fit
Experimentally favored (e.g. high efficiency, small background)
Not so great but tolerable
Snyder-Quinn 1993
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2 = (113 6)º 2 = (113 6)º +2717
22 ( () from B) from B00
No discrete ambiguity in 0-180 deg. ! Important in the future.No discrete ambiguity in 0-180 deg. ! Important in the future.
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22 ( () from B ) from B
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22 W.A. W.A.
CKM (indirect)
All W.A.
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Direct CP violation and Direct CP violation and 3 3 (())
13
2VudV*ub
VtdV*tb
VcdV*cb
u
b
u
uc
sW
B+d
D0
Vcs
V*ub
fCOM
3 u
b
u
su
c
W
B+d D0
+Vus
V*cb _
fCOM
3
B D(*)K(*)B D(*)K(*)
Choice of fCOM very imporant !Choice of fCOM very imporant !
Color suppressed Color allowed
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AArErE to measure to measure 3 3 (1) GLW(1) GLW
fCOM = DCPfCOM = DCP
[PLB 253,483; 265,172(’91)]
+-/ +- (CP=+1) , S0/..(CP= 1)
Gronau-London-Wyler
-1.0 0.0 1.0 0.0 1.0
ACP=, RCP= rB, B, 3 need more statisticsneed more statistics(four observables, three unknowns)
O∆∆O score
22
AArErE to measure to measure 3 3 (2) ADS(2) ADS
fCOM = DDCSDfCOM = DDCSD
Atwood-Dunietz-Soni
Not yet observed,but important limit on rB
already available
Not yet observed,but important limit on rB
already available
OX∆O score[PRL 91,171801(’03)]
color suppresed
Cabibbo suppresed
23
AArErE to measure to measure 3 3 (3) Dalitz(3) Dalitz
• fCOM = Ks
OO∆O score Giri-Grossman-Soffer-Zupan
[PRD 68,054018(’03)]
B+:
B-:
m+=m(Ks+), m=m(Ks) CPV: Asymmetry in Dalitz dist.:
r
r |A2|
|A1|r =
2m
2m
0 D 2m
2m
0 D obtainfromtagged D0
(D*+ D0+)sample
24
Signal yieldsSignal yields
232M BB232M BB
275M BB275M BBD0K*
D0KD*0K[D00]209
signals58signals 36
signals
49 signals
90 signals282 signals
[hepex/0504039]
[hepex/0411049] [hepex/0504013]
E E E
25
Dalitz Plots: Dalitz Plots: DD00KK
232M BB232M BB
275M BB275M BB B+ B
B+ B
26
33 Fit Results Fit Results
-100 0 100
0
0.1
0
.2
0.3
3(deg)
rB
-100 0 1000
0
.1
0.2
0
.3
rB
3(deg)
D0K*D0K D*0K [D00]
D0KD*0K [D00]
3 = (68 13 11model )º 3 = (68 13 11model )º +1415
3 = (67 28
13 11model )º
3 = (67 28
13 11model )º [hepex/0507101]
[hepex/0411049]
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33 ( () from B ) from B D D(*)(*)KK(*)(*)
3 = (63 )º 3 = (63 )º +1512
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Unitarity Triangle with Angle MeasurementsUnitarity Triangle with Angle Measurements
1 = (22 1)º 2 = (99 )º3 = (63 )º
+138+1512
1 + 2 + 3
= (184 )º+2014
(naïve sum by the speaker)
29
All combinedAll combined
ρ = 0.216 ± 0.036 η = 0.342 ± 0.022
30
SummarySummary• Recent remarkable progress in 2 and 3 measurements
– Now overconstraining CKM just from angle measurements (i.e. from CP asymmetries alone !)
• O(10º) achieved using new ideas !– for 2, DK Dalitz for 3 – Still limited by statistics
• Improvements in the future guaranteed
• To compete with the 1 precision, we need– better understanding of hadronic uncertainties
• SU(2) breaking• Dalitz amplitudes, amplitude ratios, etc.
– much more data LHCb, Super B factory
1 = (22 1)º 2 = (99 )º3 = (63 )º
+138+1512
31
Backup SlidesBackup Slides
32
33
34
buW
B0
+Vud
Vcbc
d
D*
dd
bcW
B0 +
Vcd
Vubu
dD*
dd
(B0→D) ~ 1 + cos(mt) – Ssin(mt)
(B0→D) ~ 1 + cos(mt) S sin(mt)
(B0→D) ~ 1 cos(mt) S sin(mt)
(B0→D) ~ 1 cos(mt) S sin(mt)
Cabibbo favored
Cabibbo suppressed
CP
CP
S = 2(1)LR sin(213 ) : hadronic phase, R = ~0.02
ACF ADCS
mixing mixing induced CPV
[L=0 (D), 1(D) R, not same for D and D
sin(2sin(211++33): B): B00DD(*)+(*)+-- TCPV TCPVsin(2sin(211++33): B): B00DD(*)+(*)+-- TCPV TCPV42
[I.Dunietz, PLB 427,179(’98)]
B0→mixing
ADCS
ACF
35
t Distributionst DistributionsB0 D
10.6K cand.(96% purity)
B0 B0
152M BB152M BB232M BB232M BBpartial reconstruction
B0B0
D
CPCP
Full recon.
-10 -5 0 5 10 -10 -5 0 5 10t(ps)
89.3K signals
Good tagLepton tag
background
D
D D
[hepex/0504035] [PRL 93,031802(04)]
D D
D D
36
sin(2sin(211++33): Summary): Summary
D*
D
D
(c~0 if ~0 or 180 deg.)
37
Extraction of Extraction of 33??
estimated formB (B Ds
)[SU(3) symmetry]
No significantconstraint yet !
R