FPCP 2004 Daegu, Korea

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CP Violation in sin2?/?2 from ??, ?? and ??
FPCP 2004 Daegu, Korea
Adrian Bevan
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Talk Overview

• Physics Motivation
• CP Studies of B???
• B???
• B???
• Impact on the Unitarity Triangle
• Conclusions

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CP Violation effects under study

• (direct) CP violation in decay
• CP violation in interference of mixing and decay
  (Im? ? 0)

time integrated effect number counting
time dependent effect relevant for measuring
Unitarity Triangles angles!
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Analyse time evolution of B0B0 system (assume
DG0)
Also need to worry about tagging dilution
resolution function
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CP Violation in B0 ?hh- hr,p
Tree Level

• ? measure ?eff
• need to bound ?eff-? (shift from loops)
• different Penguin/Tree for different decays

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Isospin Analysis
Bounds ?eff-? SU(2) relates different
hh final states triangles for ??/??
pentagons for ?? Q2B / or a Dalitz plot analysis
Gronau-London PRL65, 3381 (1990) etc
Snyder-Quinn PRD48, 2139 (1993) etc
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B0?pp- results
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Comparison of the B0???- Results

• Belle has observed CPV
• in B??? at a level of 5.2?
• 3.2? evidence for direct
• CPV from Belle
• Not supported by BaBar
• measurement

gt3? difference between BABAR and Belle results
Average with care!
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?? Isospin Analysis need B???-, ??0 and ?0?0
limiting factor is B0?p0p0
(227e6 B Pairs)
4.9s
BABAR CONF-04/035
First measurements of C?0?0
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Model Dependent Constraints on ?
M.Gronau and J.L.Rosner Phys. Rev. D65, 093012
(2002)
SU(2) is not the whole story
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VV final state S, P, D wave components need
angular analysis to determine CP content of
decay ?? is almost 100 longitudinally polarised
CP even helicity zero state dominates
Transverse (Mixed CP state) Set STranCTran0
vary for systematics
Longitudinal (CP even) SLong CLong
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(227e6 B Pairs)
Limiting factor in the ?? isospin analysis
First result published in PRL 91, 171802 (2003)
BABAR CONF-04/037
ML fit using 8 inputs mES, ?E, tagging,
m??-, cos?H,,MVA
mES
Events / 0.01 GeV

• Dominant Systematics
• a1? interference 7.5 events
• PDF variations 6 events
• B bkgd 5.8 events

BaBar preliminary
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Use Isospin analysis for longitudinal polarisation
hep-ex/0404029
(88e6 B Pairs)
Accepted for publication in PRL
PRL 91 (2003) 171802 PRL 91 (2003) 221801
(227e6 B Pairs)
BaBar CONF-04/037
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Assumptions in the use of SU(2) with ??-
Assume Gronau-London Isospin analysis (use SU2
without electroweak penguins) Neglect I1
component of amplitude (should be O(?? /m?
)2?4) Neglect Interference between signal and
a1?, ???, ??0?-?0 final states (actually we
have now estimated this find a small
systematic 0.02 for SLong CLong)
Falk et al, PRD 69 011502 (2004)
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Preliminary Result
121e6 B pairs for -

• 314 ?34 signal events

Isospin analysis gives
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??- is not a CP eigenstate can cut on Dalitz
plot to analyse ? bands Quasi-2- body approach
(BaBar result from LP 03) Better to
analyse Dalitz plot
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Quasi-2-body Approach
Cut on Dalitz plot and fit time dependence
Lipkin et al method PRD 44 1454 (1991)
Fit MBC-?E plane for ??
(152e6 B pairs)
hep-ex/0408003
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Background Dominated
Signal region
hep-ex/0408003
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Basis for Dalitz plot analysis of B0 ? (??)0

• Extract ? and strong phases using interference
  between amplitudes
• Amplitude A3? dominated by ??-, ?- ?, ?0 ?0 and
  radial excitations
• Transform Dalitz Plot (DP) to (i) move signal
  away from boundaries of DP
• (ii) simplify efficiency correction and
  treatment of resolution in DP

(?0??- helicity)
(m0m??-)
Snyder-Quinn method PRD 48 2139 (1993)
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(213e6 B Pairs)
hep-ex/0408099
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• Fit time evolution of Dalitz Plot
• Convert measured parameters
• into CPV observables

hep-ex/0408099
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Results from CP analysis of B0 ? (??)0
All strong phases And amplitudes extracted from
DP
Theoretically Clean SU(2)
BABAR CONF-04/038
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Again SU(2) is not the whole story
Model Dependent constraint of ? in B???. Assume
- SU(3) exact for penguins - strong phase
difference assumed to be small (0?) to
remove 8-fold ambiguity on possible
solutions - neglect color suppressed EWP -
neglect annihilation exchange diagrams - use
CLEO BaBar Belle B?VP data to constrain
SU(3) breaking effects B?KK etc
Gronau Zupan hep-ph/0407002
Belles result corresponds to Same model
dependent analysis of BaBar Dalitz Plot result
By GZ has a 50 experimental error.
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Summary of constraints on ?
?? and ?? dominate the constraint on ?
Straight average of BaBar and Belles ??
measurements
Mirror solutions disfavored
CKM Fitter http//ckmfitter.in2p3.fr/
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Indirect constraints give
(only BaBar ??,??)
UT Fitter http//utfit.org
68, 95 CLs shown
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Conclusion

• 3 Milestones in the last year
• Observation of CPV in B??? decays (Belle)
• ACP(?t) from ??- (BaBar)
• Dalitz Plot analysis of B??? (BaBar)
• Independent crosschecks available
• SU(2) with ??
• SU(2) ?? Dalitz Plot result
• SU(3) with ??
• Combining direct measurements using SU(2)
• Expect even greater precision in the future

The B-factories have measured ?
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Backup Material Observables of the ?? Q2B
analysis
Non CPV observables
ACP time integrated S - related to sin2? C
- related to direct CPV ?S - related to
strong phase differences between A?? ?C -
related to difference in width of
B(B)??(-)?-() and C.C. Also A-, A-