  In a recent paper, 8 semileptonic parameters were defined to specify the most
general Lorentz-invariant spin correlation functions for 2-body tau decays.
These parameters can be used to search for anomalous longitudinal-versus
transverse polarized-partial widths, for non-CKM-type leptonic CP violation,
and for leptonic T violation. They can also be used to bound the effective-mass
scales ``Lambda" for new physics arising from additional Lorentz structures,
e.g. from lepton compositeness, tau weak magnetism, weak electricity, or
second-class currents. It is emphasized that (i) for these tests ``different
modes have different merits" and that (ii) the parameters can be measured
either by using spin-correlation techniques without polarized beams, or with
longitudinally polarized beams.
