Abstract
We study the branching ratios of the radiative leptonic B c decays of B c + →l + ν l γ (l=e,μ,τ). In our analysis, the form factors for B c →γ transitions are calculated directly in the entire physical range of momentum transfer within the light front framework. We find that the decay branching ratios of B c + →e + ν e γ, B c + →μ + ν μ γ, and B c + →τ + ν τ γ are 2.0 × 10 -5 , 2.3 × 10 -5 , and (8.8 - 10.7) × 10 -5 , compared with 1.3 × 10 -9 , 5.6 × 10 -5 , and 1.4 × 10 -2 for that of B c + →e + ν e , B c + →μ + ν μ , and B c + →τ + ν τ , respectively. ©1999 The American Physical Society.