Radiative $B_c$ meson decays $B_c\to \gamma u\bar{d}$

Abstract

Inclusive radiative decays $B_c\to \gamma u\bar{d}$ are considered. It is shown that photon emission allows one to bypass the chiral suppression and leads the increase of the branching fraction by about four orders of magnitude. The estimates of exclusive decay branching fractions of $B_c$ meson into different sets of $\pi$ mesons are also given.

Comments: minor changes, some references added