Probing Lepton Flavor Universality with Pion Decays

Searches for violation of lepton flavor universality are topical due to hints of discrepancies with Standard Model expectations in studies involving muons, B mesons, and beta decays which may be related by tests of the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. The status and prospects of pion decay experiments which offer the most precise tests of e − μ universality are discussed.