Recent tau results from CLEO

A data sample of 4.5 x 10(6) tau pairs has been analyzed to obtain a limit on the mass of the tau neutrino and also to search for CP violation in tau decay. The neutrino mass study utilizes a two-dimensional extended likelihood analysis that includes the dependence of the end-point population on m(nu tau) and also, for the first time, incorporates an explicit background contribution. We use the the decays tau --> 5 pi nu(tau) and tau --> 3 pi 2 pi(0) nu(tau) to obtain an upper limit of 30 MeV/c(2) at 95% C.L. In addition, we have performed the first search for CP violation in tau lepton decay. CP violation could appear as an asymmetry in the angular distribution of the decay tau(-) --> K-0 pi(-) nu(tau) relative to the charge conjugate decay. We define and measure an observable assymetry parameter and find no evidence for CP violation in this decay.