Charm decays and $\tau$ physics at Belle and Belle II

TL;DR

This paper reviews recent charm baryon decay measurements and tau physics studies at Belle and Belle II, highlighting new CP violation searches and lepton-flavor violation investigations.

Contribution

It presents first measurements of certain charm baryon decay modes and reports the first search for CP violation in specific tau decays.

Findings

First measurements of several charm baryon decay modes

First search for CP violation in tau to pi K_S nu decays

New studies on lepton-flavor-violating processes in tau decays

Abstract

Beyond $B$ physics, charm and $\tau$ physics constitute a central part of the Belle and Belle II physics programs. Here, we present recent results on charm baryon decays, including first measurements and observations of several previously unmeasured modes, together with new studies in $\tau$ physics. Particular emphasis is placed on searches for CP violation in $\tau$ decays and lepton-flavor-violating processes. In this context, a search for CP violation in $\tau \to \pi K_{S} \nu_{\tau}$ decays is reported for the first time.