Efficacy of scalar leptoquark on $B_s\to (K^{(\ast )},D_s^{(\ast )})\tau {\bar{\nu }}_{\tau }$ decay modes

Abstract

We scrutinize the impact of various relevant scalar leptoquarks on the physical observables associated with the rare semileptonic decay processes of $B_s$ meson involving $b\to (u,c)l{\bar{\nu }}_l$ quark level transitions. We constrain the new parameter space consistent with the experimental limit on Br($B_{u,c}\to \tau {\nu }_l$), Br($B\to \pi \tau {\bar{\nu }}_{\tau }$), $R_{D^{(\ast )}},R_{J/\psi }$ and $R_{\pi }^l$ observables. Using the allowed parameter space, we compute the branching ratios, forward-backward asymmetries, lepton and hardon polarization asymmetries of $B_s\to (K^{(\ast )},D_s^{(\ast )})\tau {\bar{\nu }}_{\tau }$ decay modes. Forbye, we look at the possibility of existence of lepton non-universality in these processes.

Comments: 30 pages, 16 figures