Model-independent search for the decay B+→l+νlγ

We present a search for the radiative leptonic decay B + → ℓ + ν ℓ γ , where ℓ = e , μ , using a data sample of 465 × 10 6 B ¯¯¯ B pairs collected by the BABAR experiment. In this analysis, we fully reconstruct the hadronic decay of one of the B mesons in Υ ( 4 S ) → B + B − decays, then search for evidence of B + → ℓ + ν ℓ γ in the rest of the event. We observe no significant evidence of signal decays and report model-independent branching fraction upper limits of B ( B + → e + ν e γ ) < 17 × 10 − 6 , B ( B + → μ + ν μ γ ) < 24 × 10 − 6 , and B ( B + → ℓ + ν ℓ γ ) < 15.6 × 10 − 6 ( ℓ = e or μ ), all at the 90% confidence level