New physics effects in leptonic and semileptonic decays

We discuss the possibilities of extracting the constraints on New Physics by using the current data on the leptonic and semileptonic decays of pseudoscalar mesons. In doing so we use a general low energy Lagrangian that besides the vector and axial operators also includes the (pseudo-)scalar and tensor ones. In obtaining constraints on New Physics couplings, we combine the experimental information concerning several decay modes with the accurate and precise lattice QCD results for the hadronic matrix elements. We propose to study new observables that can be extracted from the angular analysis of the semileptonic decays and discuss their values both in the Standard Model and in some specific scenarios of physics beyond the Standard Model.

Automated summary

This study discusses extracting constraints on New Physics using current data on leptonic and semileptonic decays of pseudoscalar mesons. By combining experimental information with precise lattice QCD results, constraints on New Physics couplings are obtained. New observables from angular analysis of semileptonic decays are proposed and values in the Standard Model and beyond are discussed.