Exploring Lepton Non-universality in $$b \rightarrow c l \bar{\nu }_l$$ Decay Modes in the Light of Recent Experimental Data

The observation of lepton non-universality in B sector has become a challenge for universality lovers. Recently, the LHCb Collaboration has added a new \(R_{J/\psi }\) ratio into this challenging area, which has a \(2\sigma \) deviation from its standard model prediction. In this regard, we present a model independent analysis of \(b \rightarrow c l \bar{\nu }_l\) decays in order to scrutinize the presence of lepton universality violation in B sector. We first perform a global fit to \(R_{D^{(*)}}\) data. We then estimate the lepton non-universality parameters of \(B_c \rightarrow (\eta _c, J/\psi ) l \nu _l\) and \(B_s \rightarrow D_s^{(*)} l \bar{\nu }_l\) decay processes.