An approach to new physics at LHCb: study of penguin pollution to ΦS(BS⁰ → J/ΨΦ) using BS⁰ → J/ΨK*⁰ decays, and search for a light A01 Higgs boson in the NMSSM

Abstract

This research project will be carried out doing data analysis in the LHCb collaboration. LHCb is one of the four big experiments running in the Large Hadron Collider at CERN, and is mainly designed to make precise measurements of CP violation and to study rare decays of B and D mesons. In particular, the research plan proposed here will focus in a time integrated analysis of Bs⁰ → J/ψK*⁰ decays with 3 inverse femtobarns of LHCb data to measure the branching fraction, polarization fractions and direct CP asymmetries. These observables will afterwords be used to compute the hadronic parameters which describe the loop diagram (penguin) effects in the Bs⁰ → J/ψϕ channel, which is considered to be the “golden” mode to measure the weak phase of the Bs⁰ mixing. This CP violating phase is predicted by the Standard Model to be very small, and penguin contributions could be confused with new physics phenomena if not taken into account. In addition, a search of A1⁰ → μ⁺μ⁻ decays, where A1⁰ is a light CP-odd Higgs boson in the NMSSM, is part of the research plan as well.