Angular and CP-Violation Analyses of (B)over-bar → D*+ l-(ν)over-barl Decays at Hadron Collider Experiments

The (B) over bar -> D*(+)l(-)(nu) over bar (l) branching fractions ratio between muon and tau lepton decay modes R(D*) has shown intriguing discrepancies between the Standard Model prediction and measurements performed at BaBar, Belle, and LHCb experiments, a possible sign of beyond the Standard Model physics. Theoretical studies show how observables related to the (B) over bar -> D*(+)l(-)(nu) over bar (l) differential decay distribution can be used to further constrain New Physics contributions, but their experimental measurements are lacking to date. This article proposes the measurement of (B) over bar -> D*(+)l(-)(nu) over bar (l) angular and CP-violating observables at hadron collider experiments, by exploiting approximate reconstruction algorithms using information from detectable final-state particles only. The resolution on the phase space variables is studied using (B) over bar -> D*(+)l(-)(nu) over bar (l) decays simulated in a forward detector geometry like LHCb. A method to correct the observable values for the reconstruction inaccuracies based on detector simulation is successfully tested on simulated data and the decrease in precision with respect to a perfect reconstruction is evaluated. The D*(+) longitudinal polarization fraction and the A(T)((2)) CP-violating observable can be measured losing a factor of 2 and 5 in precision, respectively. The extraction of angular distributions from the template fit selecting (B) over bar -> D*(+)l(-)(nu) over bar (l) decays and associated systematic uncertainties are also discussed.