Bounding the Tau Neutrino Magnetic Moment from the Process E+ E- --> Gamma Nu Anti-Nu

Abstract

In a class of $E_6$ inspired models with a light additional neutral vector boson, we discuss the effects of the magnetic moment of the tau neutrino by analyzing $e^{+}e^{-}$ $\to $ $\gamma \nu \bar{\nu}$ at the $Z$-pole. We take into account present scenarios for the extra Abelian group and vary extra neutral gauge boson mass beyond the present experimental exclusion limits. The present LEP experimental results prove us to set an upper bound on the magnetic moment of the tau neutrino: $\kappa_{\nu_{\tau}}$ $ \leq $ 1.83*10$^{-6}$ .