The annihilation decays $B^-_c \to η^{'}(η,π^0) l^- \barν$

Abstract

We investigate the simileptonic OZI-forbidden annihilation decays $B^-_c \to η^{'}(η,π^0) l^- \barν$ for $l=μ,e$ in the perturbative QCD, and carry out a precise calculation without any approximation for the one-loop contributions, which involves integrals of 4- and 5-point loop functions. Our results show that the branching ratios of decays $B^-_c \to η^{'} l^- \barν$, $B^-_c \to ηl^- \barν$ and $B^-_c \to π^0 l^- \barν$, turn out to be of orders $10^{-4}$, $10^{-5}$ and $10^{-6}$, respectively, which could be observable in the future experiments at the LHC.