The annihilation decay B_c \to eta' l \nu

Abstract

We first investigate the semileptonic annihilation decay B_c \to \eta' l\nu in QCD. We find that the ${\eta }^{\prime }$ momentum distribution is peaked within its small recoil region due to the loop effects. The branching ratio is estimated to be $Br(B_c\to {\eta }^{\prime }l\nu )=1.6\times 10^{-4}$ for $l=\mu ,e$, which is accessible at CERN LHC.

Comments: Typo corrected. To be published in PRD