Radiative B decays in supersymmetry without R parity

Abstract

We present a systematic analysis of all the contributions at the leading log order to the branching ratio of the inclusive radiative decay B→Xs+γ in the framework of supersymmetry without R parity. The relevant set of four-quark operators involved in QCD running are extended from six (within the standard model and the minimal supersymmetric standard model) to 24, with also many new contributions to the Wilson coefficients of (chromo)magnetic penguins for either chiral structure. We present complete analytical results here without any a priori assumptions on the form of R-parity violation. Mass-eigenstate expressions are given; hence the results are free from the commonly adopted mass-insertion approximation. In the numerical analysis, we focus here only on the influence of the trilinear λ′ijk couplings and report on the possibility of a few orders of magnitude improvement for the bounds on a few combinations of the λ′ couplings. Our study shows that the Wilson coefficients of the current-current operators due to R-parity violation dominate over the direct contributions to the penguins. However, the interplay of various contributions is complicated due to the QCD corrections which we elaborate here