CP violation in [formula omitted] decays

Abstract

Establishing CP violation in B 0 ( B ¯ 0 ) → l + l − decays requires a measurement of polarization of the final lepton pair, or a precise determination of the B 0 → l + l − and B ¯ 0 → l + l − rates. We first argue that if the amplitudes of these decays are dominated by the scalar and pseudoscalar Higgs penguin diagrams, as happens, e.g., in supersymmetry with large tan β , the CP asymmetries depend practically on only one CP violating phase. This phase can be large, of the order of the CKM phase, leading to large CP asymmetries in the τ + τ − decay channel of B d 0 ( B ¯ d 0 ) mesons, potentially measurable in Belle or BaBar experiments. Secondly, we show that the existing TAUOLA τ-lepton decay library supplemented by its universal interface can efficiently be used to search for B 0 ( B ¯ 0 ) → τ + τ − decays, and to investigate how the CP asymmetry is reflected in realistic experimental observables.