Rare radiative leptonic decays B_{d,s}-> l^+l^-γ

Abstract

Long-distance QCD effects in $B_{d,s}\to\ell^+\ell^-γ$ decays are analyzed. We show that the contribution of the light vector-meson resonances related to the virtual photon emission from valence quarks of the $B$-meson, which was not considered in previous analyses, strongly influences the dilepton differential distrubution. Taking into account photon emission from the $b$-quark loop, weak annihilation, and Bremsstrahlung from leptons in the final state, we give predictions for dilepton spectrum in $B_{d, s}\to \ell^+\ell^-γ$ decays within the Standard model.