Abstract
Within the light front framework, we calculate the form factors for B→γ transitions directly in the entire physical range of momentum transfer. Using these form factors, we study the radiative decays of B→lν l γ and B s(d) →νν + ̄γ. We show that the decay rates of B→lν l γ (l=e,μ) and B→νν + ̄γ are larger than that of the corresponding purely leptonic modes. Explicitly, in the standard model, we find that the branching ratios of B→μν μ γ and B s νν + ̄γ are 1.3×10 -6 and 2.0×10 -8 , in contrast with 2.3×10 -7 and 0 for B→μν μ and B→νν + ̄, respectively.