Search for charged lepton flavor violating decays of ? (1S)

Abstract

We present a search for the charged lepton-flavor-violating decays ?(1S) ??�??? and radiative charged lepton-flavour-violating decays ?(1S) ? ??�??? [?,?? = e, ?, ?] using the 158 million ?(2S) sample collected by the Belle detector at the KEKB collider. This search uses ?(1S) mesons produced in ?(2S) ? ?+?? ?(1S) transitions. We do not find any significant signal, so we provide upper limits on the branching fractions at the 90% confidence level. [Figure not available: see fulltext.] � 2022, The Author(s).