Test of CP-invariance in e+e−→Z0→τ+τ− and a limit on the weak dipole moment of the τ lepton

Using a sample of 5558 Z0 → τ+τ− decays produced at LEP a direct test of CP-invariance in the neutral current reaction e+e− → τ+τ− is performed. Samples of events where eachy τ decays into a single particle have been isolated for the construction of CP-odd observables. Three different event classes are considered: lepton-lepton, lepton-hadron, and hadron-hadron. No evidence for a non-zero expectation value of the considered CP-observables and …