Angular distribution as an effective probe of new physics in semihadronic three-body meson decays

We analyze, in a fully model-independent manner, the effects of new physics on a few semihadronic three-body meson decays of the type Pi → Pff1f2, where Pi, Pf are well chosen pseudoscalar mesons and f1,2 denote fermions out of which at least one gets detected in experiments. We find that the angular distribution of events of these decays can probe many interesting new physics, such as the nature of the intermediate particle that can cause lepton-flavor violation or presence of heavy sterile neutrino or new intermediate particles or new interactions. We also provide angular asymmetries which can quantify the effects of new physics in these decays. We illustrate the effectiveness of our proposed methodology with a few well chosen decay modes showing how we can probe certain specific new physics possibilities without necessarily worrying about any hadronic uncertainties.