Flavour Changing Charged Current Within and Beyond the Standard Model

Abstract

We study B ! D and B ! D flavour changing charged current decay processes. These processes are interesting due to having persistent anomalies, RD and RD , first reported by Belle in 2007 and later by the different experiment like LHCb, Belle and BABAR. These anomalies hint physics beyond-the-Standard Model that is commonly named as new physics. For theoretical framework to study these transitions, for all possible dimension-six operators including new physics in model independent way, we write a low-energy effective Hamiltonian. We used the Wilson coefficients that are obtained from a numerical fit to all existing data to predict our observables. For numerical predictions we used HQET form factors for both transitions. We focus on B ! D decay that provides interesting angular observables due to cascade decay of D ! D . Within and beyond the standard model our findings match with the known results in model independent way for angular observables.