In particle physics the semileptonic decay of a hadron is a decay caused by the weak force in which one lepton (and the corresponding neutrino) is produced in addition to one or more hadrons. An example for this can be
This is to be contrasted with purely hadronic decays, such as â + , which are also mediated by the weak force.
Semileptonic decays of neutral kaons have been used to study kaon oscillations.