The role of leptonic cascades in $B_c\to B_s$ at the LHC

Abstract

We study the feasibility and advantages of investigating the $c\to s$ decay channel of the $B_c$ meson through the cascade decay $B_c\to B_s\pi$, $B_s\to D_s\ell \nu$. We take into account possible contaminations coming from the vector excitations (like $B_s^{\ast }$, $D_s^{\ast }$ or $\rho$ in the intermediate stages of the cascade) too, as well as the opposite cascade $B_c\to B_s\ell \nu$, $B_s\to D_s\pi$. We show how the $p_T$ distribution of the pion and the lepton can possibly help to differentiate between various form factor models, for which we either need more integrated luminosity at the LHC, or a high-luminosity $e^{+}{e}^{-}$ B factory producing $B_c$ mesons too.

Comments: 6 pages, 2 figures. Dedicated to the memory of our colleague Debrupa Chakraverty