engleski

Flavour-violating charged lepton decays in seesaw-type models

Analytic expressions of lepton-flavour- and lepton- number-violating decays of charged leptons are derived in the context of general SU(2) L ⊗ U(1) Y seesaw scenarios that are motivated by grand unified theories (GUT's) or superstring models, in which left-handed and/or right-handed neutral singlets are present. Possible constraints imposed by cosmology and low-energy data are briefly discussed. The violation of the decoupling theorem in flavour- dependent graphs due to the presence of heavy neutral leptons of Dirac or Majorana nature is emphasized. Numerical estimates reveal that the decays τ- → e-e- e+ or τ- → e-μ-μ+ can be as large as 10(-6), which may be observed in LEP experiments.

Lepton flavour violation ; seesaw ; singlet Majorana/Dirac neutrinos

nije evidentirano