Single-photon decays in systems with at least one heavy quark

Abstract

Hadrons containing at least one heavy quark (charm or bottom) frequently have small enough natural widths that decay modes involving a single photon have detectable branching fractions. Photons of typical energy greater than 100 MeV have been directly detected, while those of lower energy have only been inferred. Here we discuss prospects for observing direct sub-100 MeV photons in specific radiative decays of charmed and bottom vector mesons, as well as a spin-excited heavy baryon.