TEST FOR MAXIMAL P, MAXIMAL C VIOLATION IN E-E+ COLLISIONS FROM BEAM-REFERENCED SPIN-CORRELATION FUNCTIONS

For unpolarized beams in e-e+ collisions at the Z0, beam-referenced spin-correlation functions for the production-decay sequence e-e+-->Z0-->tau-1-tau-2+-->(h1-v)(h2+vBAR) can be easily derived using the helicity approach. For tau-1--->pi-1-v, for example, this reaction is analyzed relative to the final pi- momentum vector. The most interesting result is an azimuthal correlation function I(phi-e,phi) where the azimuthal angles are defined relative to the final pi-1-. I(phi-e,phi) allows one to simply test for maximal P, maximal C violation in the Z0-->tau-1-tau-1+ coupling. For e-e+ collisions in the UPSILON or J/psi regions, I(phi-e,phi) can be used to test for a complex phase in the gamma*-->tau-tau+ coupling. Previously it was shown that the measurement of the energy correlation function I(E(A),E(B)) for Z0-->tau-1-tau-1+-->A-B+X determines independently the fundamental parameters sin2-theta-W, the tau Michel parameters, and for hardronic tau decays the analogous chirality parameter xi-A which tests for righthanded currents. Now by referencing this energy correlation function to the incident e- beam direction, the associated ideal statistical errors for these parameters for the case of hadronic tau decays are reduced only by about 25%.