A window for New Physics in Bs?KK decays

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A window for New Physics in Bs?KK decays

• Joaquim Matias
• Universitat Autònoma de Barcelona
• David London JM, PRD (2004)
• David London JM Javier Virto, PRD (2005)
• February 2005

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• Search for New Physics

Precision Flavour Physics Era
B Physics ExperimentTheory
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• How do we prove for NP in CP violation ?

• Overdetermining the Unitarity Triangle
• Determination of sides

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• CKM fit
• Compare with the determination of angles from
  CP-asymmetries and ltBRgt.
• Two strategies a) consistency check
• b) measure NP

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• CP violation in non-leptonic B decays

• Several channels
• Fundamental role in determining b and g but
  also New Physics
• Main problem How to deal with Hadronic Matrix
  Elements
• Construct clean observable with small QCD
  Polution.
• Evaluation of hadronic parameters from QCD.
• Flavour Symmetries to extract maximal
  information from data.
• -Main hypothesis based on experimental data
• There are NO sizeable New Physics effects in b?d
  penguin amplitudes.
• If there is Physics beyond the SM will affect
  b?s penguin amplitudes.

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• Anatomy of Bs?KK- decay
• STANDARD MODEL DESCRIPTION

• It is governed by the quark-level process
• T Tree colour allowed, P gluonic penguins,
  PCEW colour suppressed EW penguins, E exchange
  and PA Penguin Annihilation topologies.
• Two types of contributions charged-current
  VubVus AuCC
• 
  penguin VubVus(Pu-Pt)VcbVcs(Pc-Pt)

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• The SM amplitude can be written
• Hadronic parameters
• Remarks
• - ?C is irrelevant in the
  Standard Model but not
• in presence of New
  Physics.
• - All factorizable
  corrections to d drop out.

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• BEYOND STANDARD MODEL
  DESCRIPTION
• In presence of New Physics in the b?s penguin
• NP operators assumed same size as SM b?s penguin.
• There are many
  (qu,d,s,c)
• All New Physics strong phases are negligible
• - Aq and Fq are process
  dependent.
• The amplitude is now

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• There are 3 measurements in Bs?KK- decay
• From the time-dependent CP asymmetry (Adir
  and Amix)
• In the SM these CP asymmetries are
• AdirSM(Bs?KK-)f(d,?,g) and
  AmixSM(Bs?KK-)g(d, ?,g, Fs)
• CP Averaged Branching Ratio in the SM

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• In presence of New Physics the SM CP asymmetries
  and CP-averaged branching ratio are modified
• Total number of parameters
• BNP, DNP and MNP are complicated functions of
  ALL these parameters.

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• Parameter determination
• Weak parameters measured independently
• CKM angle g
• B?DK
  unaffected by New Physics
• a from
  B?pp, B??p, B???
• ß from
  Amix(Bd(t)?J/?Ks)
• CKM fit.
• Weak mixing phase Fs from CP violating Bs?J/?F
• NP contributions to the mixing Fs FsSMdFs
• contribution controlled
  by Bd(t)?J/?Ks lt20

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• Hadronic Parameters
• Keypoint U-spin (interchange d?s) related
  process Bd?pp-
• quark level transition
  available to B Factories.
• no New Physics
  contribution.
• Amplitude in SM
• Wolfenstein parametrization in SM
• 
  Same functional dependence
  

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• Can we determine d, q and C?
• Present Experimental Situation
• Babar and Belle are inconsistent
• If we average naïvely the asymmetries
• A large direct CP asymmetry from Belle (large
  strong phases) would be troublesome for QCD-NLO
  factorization.
• Three measurements Adir(Bd? pp), Amix(Bd? pp)
  and BR(Bd?pp)
• Total parameters in SM
• 
  - 3 hadronic parameters
• 
  - 2 weak parameters

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From Adir(Bd? pp), Amix(Bd? pp), BR(Bd?pp),
Amix(Bd?J/YKs) and CKM fit











BABAR
BELLE


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Table of results From U-spin
breaking effects
Our predictions for Amix, Adir of Bs?KK and Rds
in SM Also from the Bd?pp and BR(Bs?KK)
we can give a prediction for g in SM
350 g
740 In the
NEAR FUTURE we will MEASURE NEW PHYSICS
Adir(Bs? KK), Amix(Bs?
KK),
BR(Bs?KK), Amix(Bs?J/YF)

Observable (SM) Babar Belle
Adir(Bs? KK-) (-1 , 1) (-.02 , .18)
Amix(Bs? KK-) (-1 , 1) (-.19 , .05)
Rds (0.1 , 13.9) (3.6 , 85.5)


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In the meanwhile Consistency check for the
PRESENCE of NEW PHYSICS In the SU(3)
limit depend on four theoretical parameters -
Penguin parameters - Weak mixing angle
- CKM angle
CKM fit (Rb and Rt) Including all
theoretical uncertainties And
experimental errors at 1s
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Alternative in the future DETERMINE
GAMMA/PRESENCE OF NP Once the CP asymmetries of
Bs?KK- are measured SM range strongly
restricted Sensitivity to U-spin breaking is
very reduced Allowed region to the SM


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• Conclusions

• Non-leptonic B decays are playing a
  fundamental role in the exploration of CP
  violation.
• Recent measurement of BR(Bs?KK-) together
  with the future data on the CP asymmetries
  Adir(Bs?KK-) and Amix(Bs?KK-) will open
  exciting new perspectives and strategies
• To search for New Physics signals in B decays
• To determine CKM angle gamma

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• Present experimental situation is quite
  uncertain
• Babar and Belle are inconsistent
• If we average naïvely
• A large direct CP asymmetry from Belle (large
  strong phases) would be troublesome for QCD-NLO
  factorization.

• Deviation from U-spin
• Only non-factorizable effects in
• Explored dependence of the predictions on U-spin
  deviations
• for
• 3. Prediction 350 ? 740