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A window for New Physics in B s → KK decays

A window for New Physics in B s → KK decays. Joaquim Matias Universitat Autònoma de Barcelona David London & JM, PRD (2004) David London &JM & Javier Virto, PRD (2005) February 2005. Search for New Physics. Precision Flavour Physics Era. B Physics [Experiment+Theory].

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A window for New Physics in B s → KK decays

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  1. 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

  2. Search for New Physics Precision Flavour Physics Era B Physics [Experiment+Theory]

  3. Overdetermining the Unitarity Triangle: • Determination of sides: How do we prove for NP in CP violation ?

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

  5. Several channels: • Fundamental role in determiningband 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. CP violation in non-leptonic B decays

  6. It is governed by the quark-level process • T’: Tree colour allowed, P’ gluonic penguins, P’CEWcolour suppressed EW penguins, E’ exchange and PA’ Penguin Annihilation topologies. • Two types of contributions: charged-current: Vub*Vus A’uCC • penguin Vub*Vus(P’u-P’t)+Vcb*Vcs(P’c-P’t) Anatomy of Bs→K+K- decay STANDARD MODEL DESCRIPTION

  7. The SM amplitude can be written: Hadronic parameters: Remarks: - θC’is irrelevant in the Standard Model but not in presence of New Physics. - All factorizable corrections to d’ drop out. Weak parameters: CKM angleg

  8. 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 (q=u,d,s,c) • All New Physics strong phases are negligible • - Aq and Φq are process dependent. • The amplitude is now:

  9. There are 3 measurements in Bs→K+K- decay: • * From the time-dependent CP asymmetry (Adir and Amix): • In the SM these CP asymmetries are: • AdirSM(Bs→K+K-)=f(d’,θ’,g) and AmixSM(Bs→K+K-)=g(d’, θ’,g,Φs) • * CP Averaged Branching Ratioin the SM:

  10. 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.

  11. Parameter determination: • Weak parameters measured independently: • CKM angle g : B→DK unaffected by New Physics α from B→pp, B→ρp, B→ρρ β from Amix(Bd(t)→J/ψKs) CKM fit. • Weak mixing phase Φs from CP violating Bs→J/ψΦ: • NP contributions to the mixing Φs= ΦsSM+δΦs • contribution controlled by Bd(t)→J/ψKs <20%

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

  13. 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: • But Fd from Amix(Bd→J/YKs) and from QCD sum rules

  14. From Adir(Bd→ pp), Amix(Bd→ pp), BR(Bd→pp), Amix(Bd→J/YKs) and CKM fit BABAR BELLE

  15. Table of results From + U-spin breaking effects Our predictions for Amix, Adir of Bs→KK and Rdsin 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 MEASURENEW PHYSICS: Adir(Bs→ KK), Amix(Bs→ KK), BR(Bs→KK), Amix(Bs→J/YF)

  16. 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 1σ:

  17. Alternative in the future: DETERMINE GAMMA/PRESENCE OF NP Once the CP asymmetries of Bs→K+K- are measured SM range strongly restricted Sensitivity to U-spin breaking is very reduced Allowed region to the SM:

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

  19. 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 ≤ γ≤ 740

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