TAU-SIGNALS OF R-PARITY BREAKING AT LEP-200

The detectability at LEP 200 of explicit R-parity breaking by tau-number (L(tau)) violating operators is considered. The assumption of L(tau)-violation is motivated by the relative lack of constraints on such couplings but similar considerations apply to explicit L(e) or L(mu)-violation. The LSP, now unstable, and not necessarily neutral, decays via L(tau)-violating modes. Only signals from the production and decays of LSP pairs are considered, thereby avoiding any dependence on the sparticle mass spectrum. Rather spectacular signals are predicted: spherical events with m leptons (usually containing at least one tau) and n jets (m, n less-than-or-equal-to 4), the most characteristic of which are like-sign tautau events. These signals are enumerated for each LSP candidate and quantitative estimates are provided for the favoured case when the LSP is a neutralino. Other new physics signals, which can mimic these signatures, are also briefly discussed.