Pure Leptonic Radiative Decays $B^{\pm },D_s\to \ell \nu \gamma$ and the Annihilation Graph

Abstract

Pure leptonic radiative decays of heavy-light mesons are calculated using a very simple non-relativistic model. Dominant contribution originates from photon emission from light initial quark. We find $BR(B^{\pm }\to \ell \nu \gamma )\sim 3.5\times 10^{-6}$ and $BR(D_s\to \ell \nu \gamma )\sim 1.7\times 10^{-4}$. The importance of these reactions to clarify the dynamics of the annihilation graph is emphasized.

Comments: 7 pages, LaTeX, 3 figures