TEST OF CP-INVARIANCE IN E+E- -] Z(0)-]TAU+TAU- AND A LIMIT ON THE WEAK DIPOLE-MOMENT OF THE TAU LEPTON

Using a sample of 5558 Z0 --> tau+-tau- decays produced at LEP a direct test of CP-invariance in the neutral current reaction e+e- --> tau+-tau- is performed. Samples of events where each tau-decays into a single charged 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 hence for CP-violation is observed. Quantitatively, we deduce from this null result an estimate on the weak dipole moment d(tau) (m(Z)2) = (-4.5 +/- 5.3 +/- 1.4) x 10(-17) e cm for the lepton-lepton signature and d(tau) (m(Z)2) = 1.4 +/- 3.7 +/-1.3) x 10(-17) e cm for the hadron-hadron signature. Combining these results we place a limit with 95% confidence of \d(tau)\ less-than-or-equal-to 7.0 x 10(-17) e cm.