Anomalous Wtb coupling effects in the weak radiative B-meson decay

Abstract

We study the effect of anomalous Wtb couplings on the B -> Xs gamma branching ratio. The considered couplings are introduced as parts of gauge-invariant dimension-six operators that are built out of the Standard Model fields only. One-loop contributions from the charged-current vertices are assumed to be of the same order as the tree-level flavour-changing neutral current ones. Bounds on the corresponding Wilson coefficients are derived.

Comments: 5 pages, 2 figures. The arXiv version remains extended w.r.t. the journal version. The first function in Eq. (12) has been corrected in v3, implying slight changes in the numerical results. Conclusions remain unaffected