Tests for Tau's Charged-Current Structure

The Lorentz structure of the tau lepton's charged-current can almost be completely determined by use of stage-two spin-correlation functions for the $\{\rho ^{-},\rho ^{+}\}$and $\{a_1^{-},a_1^{+}\}$ decay modes. It is possible to test for a ``$(V-A)$ $+$ something'' structure in the ${J^{Charged}}_{Lepton}$ current, so as to bound the scales $\Lambda$ for ``new physics" such as arising from tau weak magnetism, weak electricity, and/or 2nd-class currents. In practice, only limited information can be obtained from the $\tau \rightarrow \pi \nu$ modes.