2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37931We report a preliminary branching fraction of (1.80 +/- 0.37(stat.) +/- 0.23(syst.)) x 10^-4 for the charmless exclusive semileptonic B+ -> pi0 l+ nu decay, where l can be either a muon or an electron. This result is based on data corresponding to an integrated luminosity of 81 fb^-1 collected at the Upsilon(4S) resonance with the BABAR detector. The analysis uses BBbar events that are tagged by a B meson reconstructed in the semileptonic B- -> D0 l- nubar (X) decays, where X can be either a gamma or a pi0 from a D* decay.17 pages, 3 figures, contributed to Lepton-Photon 2005; updated referenceHigh Energy Physics - ExperimentBranching Fraction for B+ -> pi0 l+ nu, Measured in Upsilon(4S) -> B Bbar Events Tagged by B- -> D0 l- nubar (X) Decaystext