CP violation in radiative Z decays

We propose to test the CP symmetry in the reactions Z → μ+μ−γ and Z → τ+τ−γ. The experimental analysis of angular correlations allows to determine a set of effective couplings: the electric and weak dipole moments of the muon and the tau lepton, and in particular chirality conserving 4-particle couplings, all of which can be induced by CP-violation in renormalizable theories of electroweak interactions beyond the Standard Model. We update an indirect bound on the weak dipole moment of the muon.