Rare B decays as a probe to beyond standard model physics[HBNI Th129]

Abstract

The thesis predominantly deals with the rare decay B->K*ll where the full angular analysis of the final state gives rise to a multitude of observables. We show the most general parametric form of the amplitude in the standard model (SM) accounts almost all possible contributions within it, especially, the non-factorizable contributions. The formalism results into a new relation involving all the CP conserving observables and is derived without any hadronic approximations within the SM. We use the formalism to extract the hadronic parameters which are involved in this decay mode from LHCb data. The values of form factors show significant discrepancies when compared with theoretical expectations and leads to a speculation of possible evidence of physics beyond the SM. The thesis also explains, in terms of a simple and compelling new physics scenario with only two new parameters, the discrepancies between the SM expectations and the data for the neutral-current observables R_K^(*), as well as the charged-current observables R(D^(*)). While being consistent with all other data, this class of operators predicts some interesting signatures in the context of both B decays as well as high-energy collisions.