The Pure Leptonic Decays of B_c Meson and Their Radiative Corrections

TL;DR

This paper calculates one-loop radiative corrections to the leptonic decay of the B_c meson, discusses infrared divergence cancellation, and estimates long-distance effects, providing precise theoretical predictions for experimental comparison.

Contribution

It presents the first detailed one-loop radiative correction calculation for B_c leptonic decay, including divergence cancellation and long-distance effect estimation.

Findings

Radiative corrections are computed and infrared divergences are properly canceled.

The radiative decay mode can be isolated and compared with experiments.

Long-distance contributions are negligible compared to one-loop 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.