Lepton Flavour Violation Experiments -- Some Recent Developments
  Dedicated experiments searching for lepton flavour violation can be performed very sensitively using K-decays and $\mu$-decays as well as neutrinoless double $\beta$-decay and muonium to antimuonium conversion. Although there is no confirmed signal reported yet, stringent limits for parameters in speculative extensions to the standard model can be set. Some models could recently be ruled out. 
Klaus P. Jungmann (Physikalisches Institut, Universit\"at Heidelberg)