Charged-lepton flavour-violating (cLFV) processes provide a unique discovery potential
for physics Behind Standard Model (BSM). These cLFV processes explore new physics parameter space in a manner complementary to the collider, dark matter, dark energy, and neutrino physics programmes. Furthermore the observation of neutrino oscillations has clearly demonstrated that neutral lepton flavour is not conserved. This implies that cLFV can also occur in the SM enriched by massive neutrinos, although strongly suppressed (B < 10E-50). On the other hand, the simplest and most reliable BSM extensions predict measurable cLFV processes, some being even further enhanced by the recently measured large mixing angle Theta_13 and in the reach of incoming experiments.
The global program includes searches for mu => e, tau => e, and t => mu transitions at experiments hosted in Europe, the US, and Asia. The relative rates among the various transitions are model dependent and comparisons among these transitions offer powerful model discrimination. A full exploration of cLFV parameter space requires the pursuit of all available mu => e and tau => e mu transitions.
An overview of worldwide efforts in the search for charged lepton flavour violation is given.