Lepton Flavour Violation in the Neutrinoless τ Decay τ→3μ with the CMS Experiment

The lepton flavour violating decay τ→μμμ is predicted in many extensions of the Standard Model with branching ratios partially next to the current experimental upper limit of 3.2×10−8. Therefore, lepton flavour violating τ decays are an interessant option in search of new physics.