First Search for CP Violation in Tau Lepton Decay

Abstract

Using the CLEO II detector we have performed the first search for $CP$ violation in tau lepton decay. CP violation in lepton decay does not occur in the minimal standard model but can occur in extensions such as the multi-Higgs doublet model. It appears as a characteristic difference between the ${\tau }^{+}$ and ${\tau }^{-}$ decay angular distributions for the semi-leptonic decay modes such as ${\tau }^{-}\to K^0{\pi }^{-}\nu$. We define an observable asymmetry to exploit this and find no evidence for any CP violation.

9 pages, 4 Postscript figures, postscript file also available through http://w4.lns.cornell.edu/public/CLNS