Speaker
Description
Recently, various indications of lepton non-universality have been remarked in semileptonic $B$ meson decay processes, both in the neutral-current ($b \to s ll $) and charged-current ($b \to c l \bar \nu_l$) transitions. Influenced by these fascinating quotients, we examined the semileptonic decays involving the $b \to c l \nu_l$ quark level transitions. We executed it through a model independent analysis in order to survey the nature of new physics. Taking into consideration the most general effective Hamiltonian, we introduce $\Lambda_b \to \Lambda_c \tau \bar \nu_\tau$, $ B_c^+ \to \eta_c \tau^+ \nu_\tau$, and $ B \to D^{**} \tau \bar \nu_\tau$ (where $D^{**} = \{D^*_0, D_1^*, D_1, D_2^*\}$ are the four lightest excited charm mesons) processes, in the presence of new physics. We conducted a global fit to different sets of new coefficients, counting the measurements on $R_{D}$, $R_{D^{*}}$, $R_{J/\Psi}$, ${P_{\tau}}^{D^*}$, and the upper limit on Br($B_c^+ \to \tau^+ \nu_\tau$). We express the inferences of constrained new couplings on the branching ratios, forward-backward asymmetry, lepton non-universality ratios (LNU), lepton and hadron polarization asymmetry of these decay modes with respect to $q^2$.
