A closer look at observables from exclusive semileptonic $Bto(pi,rho)ell u_{ell}$ decays

This article analyses the available inputs in $btopilnu$ and $btorholnu$ decays which include the measured values of differential rate in different $q^2$-bins (lepton invariant mass spectrum), lattice, and the newly available inputs on the relevant form-factors from the light-cone sum rules (LCSR) approach. We define different fit scenarios, and in each of these scenarios, we predict a few observables in the standard model (SM). For example, $R(M) =frac{mathcal{B}(B to Mell_i u_{ell_i})}{mathcal{B}(Bto Mell_j u_{ell_j})} $, $R^{ell_i}_{ell_j}(M) =frac{mathcal{B}(Bto ell_i u_{ell_i})}{mathcal{B}(B to Mell_j u_{ell_j})}$ with M = $pi$ or $rho$ and $ell_{i,j} = e, mu$ or $tau$. We also discuss the new physics (NP) sensitivities of all these observables and obtain bounds on a few NP Wilson coefficients in $bto u tau u_{tau}$ decays using the available data. We have noted that the data at present allows sizeable NP contributions in this mode. Also, we have predicted a few angular observables relevant to these decay modes.