  The observation of $B \to \tau \bar{\mu} + \mu \bar{\tau} $ at present
experiments would be a clear sign of new physics. In this paper we calculate
this process in a 2HDM framework where the decay is mediated by the exchange of
spin zero particle with flavour changing neutral current couplings. If we
identify the scalar with the the newly discovered state at LHC with a mass $%
\sim 125 $ GeV then we get $BR(B_s \to \tau \bar{\mu} + \mu \bar{\tau}) \sim
10^{-6}$ and $BR(B_d \to \tau \bar{\mu} + \mu \bar{\tau}) \sim 10^{-7}$. We
also calculate this process in minimal supersymmetric standard model and find
$BR(B_s \to \tau \bar{\mu} + \mu \bar{\tau}) \sim 10^{-11}$.

High Energy Physics - Phenomenology;High Energy Physics - Experiment