  We study charged lepton flavour violation in low-scale seesaw models of
minimal supergravity, which realize large neutrino Yukawa couplings thanks to
approximate lepton-number symmetries. There are two dominant sources of lepton
flavour violation in such models. The first source originates from the usual
soft supersymmetry-breaking sector, whilst the second one is entirely
supersymmetric and comes from the supersymmetric neutrino Yukawa sector. Within
the framework of minimal supergravity, we consider both sources of lepton
flavour violation, soft and supersymmetric, and calculate a number of possible
lepton-flavour-violating transitions, such as the photonic decays of muons and
taus, mu -> e gamma, tau -> e gamma and tau -> mu gamma, their neutrinoless
three-body decays, mu -> e e e, tau -> e e e, tau -> mu mu mu, tau -> e e mu
and tau -> e mu mu, and the coherent mu -> e conversion in nuclei. After taking
into account the exclusion bounds placed by present experiments of lepton
flavour violation, we derive combined theoretical limits on the universal heavy
Majorana mass scale mN and the light-to-heavy neutrino mixings. Supersymmetric
low-scale seesaw models offer distinct correlated predictions for
lepton-flavour-violating signatures, which might be discovered in current and
projected experiments, such as MEG, COMET/PRISM, Mu2e, super-BELLE and LHCb.

High Energy Physics - Phenomenology