Predictions for Anomalous τ + τ − γ Production at LEP 1 Jochen Biebel and Tord Riemann

We calculate distributions for ττγ production at LEP 1 taking into account a potentially existing anomalous magnetic moment aτ of the τ lepton. The existing upper limits for |aτ | are known from the dependence of the decay Z → ττγ on a2τ and are of the order of (1− 5)%. We show that such limits are also sensitive to linear terms in aτ , which are of equal importance at |aτ | ∼ (1− 2)% and dominate below this value. Contributions from an electric dipole moment dτ do not interfere with the electromagnetic vertex or with the anomalous magnetic moment. Appropriate formulae are derived.