We report the measurements of electroweak penguin processes b → d, sγ and b → sℓ + ℓ − at the Belle experiment. The analyses are based on 152 million BB events collected at the Υ(4S) resonance with the Belle detector at the KEKB e + e − asymmetric-energy collider. The b → dγ transition is studied through exclusive decays: B 0 → ρ 0 γ, B 0 → ωγ and B + → ρ + γ. We apply fully inclusive and semi-...

Determinations of the CKM phase γ from weak nonleptonic B decays are affected by electroweak (EW) penguins and rescattering effects. In this talk I explain how the EW penguin effects can be controlled with the help of SU(3) symmetry, by relating them to tree-level amplitudes. The impact of the finalstate interactions on the determination of γ from B+ → Kπ decays is studied numerically, showing ...

Recent results from CLEO on B → Kπ indicate that the phase γ may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that γ extracted usingB → Kπ, ππ is sensitive to new physics occurring at loop level. It provides a powerful method to probe new physics in electroweak penguin interactions. Using effects due to anomalous gauge cou...

Abstract We present a method for measuring the weak phase γ using isospin analysis of three body B decays into Kππ channels. Differential decay widths and time dependent asymmetry in Bd → KSπ π mode needs to be measured into even isospin ππ states. The method can be used to extract γ, as well as, the size of the electroweak penguin contributions. The technique is free from assumptions like SU(3...

An improved method is presented for determining the weak angle γ of the unitarity triangle using decay rates for B+ → Kπ,B+ → K+K̄0 and B+ → π+η (or B0 → Kπ and Bs → Kπ), their CP-conjugate modes and the CP-averaged rate for B → π±π0. Using SU(3) symmetry, the annihilation (color-suppressed) contribution in B+(B0) → Kπ decays is subtracted away. Electroweak penguin effects are included in a mode...

The electroweak penguin mediated B → Xsll decay is a good probe to study beyond the Standard Model physics at low energy. The effect of new physics could be observed as corrections to the branching fraction, di-lepton invariant mass spectrum, and to the Wilson coefficients such as C9, C10, and a phase of C7 [1-10]. Experimentally, the exclusive B → Kll decay was observed by the Belle collaborat...

A method is described which, under the assumption of SU(3) symmetry, allows one to determine the angle γ = Arg(V ∗ ub) of the unitarity triangle from timeindependent measurements of the branching ratios for the rare two-body decays B+ → π0K+ and B → π0K−, as well as of the CP-averaged branching ratios for the decays B → π±K0 and B → π±π0, all of which are of order 10−5. The effects of electrowe...

We present a general parametrization of B → πK, π0K± and Bd → π0K, πK decays, taking into account both electroweak penguin and rescattering effects. This formalism allows – among other things – an improved implementation of the strategies that were recently proposed by Neubert and Rosner to probe the CKM angle γ with the help of B → πK, π0K± decays. In particular, it allows us to investigate th...