2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48861We analyse the sensitivities of exclusive one-prong tau branching fractions to: the tau neutrino mass; its mixing with a fourth generation neutrino; the weak charged current magnetic and electric dipole moments of the tau; and the Michel parameter $η$. Quantitative constraints are derived from current experimental data and the future constraints derivable from tau-charm factory measurements are estimated. The anomalous coupling constraints are used to constrain the tau compositeness scale and the allowed parameter space for Higgs doublet models.Invited talk at the Tau-Charm Workshop, 6-9 March 1999, SLAC, USAHigh Energy Physics - Phenomenologytext