The Pure Leptonic Decays of B_c Meson and Their Radiative Corrections

Abstract

The radiative corrections to the pure leptonic decay $B_c\to \ell {\nu }_{\ell }$ up-to one-loop order is presented. How to cancel the infrared divergences appearing in the loop calculations, and the radiative decay $B_c\to \ell {\nu }_{\ell }\gamma$ is shown precisely. It is emphasized that the radiative decay may be separated properly and may compare with measurements directly as long as the theoretical `softness' of the photon corresponds to the experimental resolutions. Furthermore with a kind of non-relativistic constituent quark model, a kind of typical long distance contributions to the radiative decays is estimated, and it is shown that the contributions are negligible in comparison with the accuracy of one-loop corrections and the expected experimental measurements.

Comments: 20 pages including 6 figures, REVTeX