$B^- \to μ^- {\bar ν}_μγ$ and the Determination of $f_B$

Abstract

We compute the rate of the decay $B^- \to μ^- {\bar ν}_μγ$ by a QCD relativistic potential model, with the result: ${\cal B}(B^- \to μ^- {\bar ν}_μγ)=0.9 \cdot 10^{-6}$. We also discuss how this decay mode can be used to access $f_B$.