Charged Lepton Flavour Violation: An Experimental and Theoretical Introduction

Abstract

Charged lepton flavour violating transitions would be a clear signal of new physics beyond the Standard Model. Their search has been carried out in a variety of channels, the most sensitive being those involving a muon: however no positive evidence has been found so far. The MEG experiment has recently set the best limit on such processes by investigating the existence of the $μ\to eγ$ decay. In the next decade several experiments are planned to pursue the search for $μ\to eγ$, $μ\to eee$, $μ\to e$ conversion in nuclei, as well as on processes involving the $τ$, to an unprecedented level of precision. In this review we want to give a pedagogical introduction on the theoretical motivations for such searches as well as on the experimental aspects upon which they are based.

Invited review prepared for La Rivista del Nuovo Cimento. 110 Pages. Updated reference list