Model-Independent Results for the Decay B+ → (ell)+ ν#ellγ# at BaBar

We present a search for the radiative leptonic decays B+ → e+ νeγ and B+ → μ+νμγ using data collected by the BABAR detector at the PEP-II B factory. We fully reconstruct the hadronic decay of one of the B mesons in Υ(4S) → B+B- and then search for evidence of the signal decay within the rest of the event. This method provides clean kinematic information on the signal's missing energy and high momentum photon and lepton, and allows for a model-independent analysis of this decay. Using a data sample of 465 million B-meson pairs, we obtain sensitivity to branching fractions of the same order as predicted by the Standard Model. We report a model-independent branching fraction upper limit of Β(B+ → (ell)+ν#ellγ#) < 15.6 x 10-6 ((ell) = e or μ) at the 90% confidence level.