Transverse Tau Polarization in Decays of the Top and Bottom Quarks in the Weinberg Model of CP Non-conservation

Abstract

We show that the transverse polarization asymmetry of the $\tau$-lepton in the decay $t\to b\tau \nu$ is extremely sensitive to CP violating phases arising from the charged Higgs exchange in the Weinberg model of CP non-conservation. Qualitatively, the polarization asymmetries are enhanced over rate or energy asymmetries by a factor of $\approx \frac{m_t}{m_{\tau }}\approx O(100)$. Thus for optimal values of the parameters the method requires $\approx 10^4$ top pairs to be observable rather than $10^7$ needed for rate or energy asymmetries. We also examine $\tau$ polarization in b decays via $b\to c\nu \tau$ and find that it can also be very effective in constraining the CP violation parameters of the extended Higgs sector.

Comments: 11,1 figure, SLAC-PUB-6083