THE TAU WEAK-MAGNETIC DIPOLE-MOMENT

We calculate the prediction for the anomalous weak-magnetic form facto r of the tau lepton at q(2) = M(Z)(2), within the Standard model. With all particles on-shell, this is an electroweak gauge invariant quanti ty. Its value is a(tau)(w)(M(Z)(2)) = - (2.10 + 0.61i) x 10(-6). We sh ow that the transverse and normal components of the single-tau polariz ation of tau pairs produced at e(+)e(-) unpolarized collisions are sen sitive to the real and absorptive parts of the anomalous weak-magnetic dipole moment of the tau. The sensitivity one can achieve at LEP in t he measurement of this dipole moment is discussed.