Search for violation of leptonic universality in semileptonic decays of strange particles in LHCb

Abstract

Theoretical studies have demonstrated that Semileptonic Hyperon Decays (SHD) can be sensitive to Beyond the Standard Model dynamics that break leptonic flavour universality (LFU). The LFU test observable defined as the ratio between muon and electron modes is sensitive to non standard scalar and tensor contributions. Moreover there is a precise SM theoretical prediction. Λ -> p μ ν was proposed as one of the most promising SHD to be studied at LHCb, due to its high acceptance efficiency and abundance in LHCb events. In addition, the electron mode has already been measured precisely and an improvement in the measurement of the BR directly translates into tighter bounds in LFU in s-u quark transitions. In this thesis is presented the blinded measurement of the branching fraction and its consequences.