Rare Decays with Lepton Flavor

Processes that violate the seemingly accidental global symmetries of the Standard Model provide a perfect hunting ground for new physics, examples being proton decay (violating baryon number), neutrinoless double beta decay (violating total lepton number), and lepton-flavor-violating decays. We will review such rare decays and classify them according to their lepton flavor information. The violation of lepton-flavor universality, as recently hinted at by LHCb's measurements of B-meson decays, will be discussed as well.