Analysis of the semileptonic $B_c\to D_s^{\ast }{\mu }^{+}{\mu }^{-}$ decay mode in the effective field theory approach

Abstract

Discrepancies have been noted between experimental measurements and Standard Model predictions for various observables related to the $B\to (K,K^{\ast },\varphi )ll$ processes. Recently, the Belle-II Collaboration observed a $2.8\sigma$ deviation from Standard Model predictions in the branching ratio of the $B\to K{\nu }_l\overline{{\nu }_l}$ decay mode. In this context, we investigate the exclusive semileptonic $B_c\to D_s^{\ast }{\mu }^{+}{\mu }^{-}$ decay mode, mediated by $b\to s$ quark level transition, using Effective Field Theory formalism. We perform a global fit to the new parameters using existing experimental data on $b\to s{\mu }^{+}{\mu }^{-}$. We then estimate the branching ratio and other observables such as forward-backward asymmetry, lepton polarisation asymmetry, and the lepton non-universality parameter of the $B_c\to D_s^{(\ast )}{\mu }^{+}{\mu }^{-}$ process. Although this process has not yet been detected experimentally, we offer predictions and discuss the observables for $B_c\to D_s^{\ast }{\mu }^{+}{\mu }^{-}$ in both the Standard Model and potential new physics scenarios.

Comments: 10 Pages, 2 Figures, Contribution to Proceedings of the 22nd Conference on Flavor Physics and CP Violation (FPCP 2024)