A General Treatment of Tau Semi-Leptonic Decays

Abstract

The most general Lorentz invariant spin-correlation functions for ${\tau }^{-}\to {\rho }^{-}\nu ,a_1^{-}\nu ,K^{\ast -}\nu ,{\pi }^{-}\nu ,K^{-}\nu$ are expressed in terms of eight semi-leptonic parameters. They are physically defined in terms of tau-decay partial-width-intensities for polarized-final-states. The parameters are also expressed in terms of a ``$(V-A)+$additional chiral coupling'' structure in the ${J^{Charged}}_{Lepton}$ current, so as to bound the scales $\Lambda$\ for ``new physics'' such as arising from leptonic CP violation, tau weak magnetism, weak electricity, and/or second-class currents. The two tests for leptonic CP violation in $\tau \to \rho \nu$ decay are generalized to $\tau \to a_1\nu$ decay and to two additional tests if there are ${\nu }_R$ and ${\bar{\nu }}_L$ couplings.

Contributed paper to LP95, Beijing. Expanded version to be submitted to Phys. Rev. Before LaTeXing, cut off "by-line" at bottom