Radiative leptonic decays of Bc meson

To the leading order, the radiative leptonic decays Bc→γℓν̄ (ℓ=e,μ ) are studied carefully. In the study, a non-relativistic constituent quark model and the effective Lagrangian for the heavy flavour decays are used. As a result, the branching ratios turn out to be of the orders of 10−5 for Bc→γμν̄ or for Bc→γeν̄. Based on the study, we point out the decays being accessible experimentally at the future LHC, and the possibility to determine the decay constant fBc through the radiative decays.