Study of angular observables in exclusive semileptonic $B_c$ decays

TL;DR

This paper analyzes angular observables and lepton flavor ratios in semileptonic $B_c$ decays using a relativistic quark model, providing predictions that could reveal new physics beyond the Standard Model.

Contribution

It offers novel predictions for angular observables and lepton flavor ratios in $B_c$ decays within the Relativistic Independent Quark Model, comparing with lattice results.

Findings

Predictions align well with lattice calculations.

Potential to discover new physics with upcoming experimental data.

Provides comprehensive $q^2$-dependent observables for $B_c$ decays.

Abstract

In this work, we investigate angular observables such as the longitudinal polarization of charged leptons, $\tau$-polarization, and forward-backward asymmetry in semileptonic $B_c$ decays. Additionally, we provide predictions for lepton flavor violating observables, the $\mathcal{R}$ ratios in the decay channels $B_c \rightarrow \eta_c (J/\psi) l \nu_l$ and $B_c \rightarrow D (D^*) l \nu_l$ across the entire $q^2$ region. Our analysis is conducted within the Relativistic Independent Quark Model, focusing on the potential model-dependent aspects of these observables. We compare our model predictions with existing lattice predictions, highlighting the strong applicability of our framework in describing $B_c$ decays. Considering the forthcoming experimental upgrades and the Run 3 data results on $B_c$ meson decays, rapid confirmation of these quantities could indicate significant discoveries of physics beyond the Standard Model. This will open up new avenues for understanding the complex flavor dynamics in heavy meson decays.