Measurement of the branching fraction of B → Xsγ and [formula omitted] in B → Xs + dγ from Belle

Abstract

The transitions b→dγ and b→sγ are flavor-changing neutral currents, forbidden at tree level in the Standard Model (SM). These decays proceed via electroweak penguin loop diagrams and can be used to test the SM and new-physics effects. The SM gives very precise predictions when the decays are considered inclusively, for this reason it is important to perform studies where as many final states as possible are reconstructed or where the decay is considered fully inclusively, without explicitly reconstructing the B meson.The large Belle data set of 711fb−1 recorded at the ϒ(4S) resonance allows for precise measurements of radiative B-decays.