Bounds on the magnetic moment and electric dipole moment of the $\tau$-neutrino via the process $e^{+}e^{-}\to \nu \bar \nu \gamma$

Abstract

Bounds on the anomalous magnetic moment and the electric dipole moment of the $\tau$-neutrino are calculated through the reaction $e^{+}e^{-}\to \nu \bar \nu \gamma$ at the $Z_1$-pole, and in the framework of a left-right symmetric model. The results are based on the recent data reported by the L3 Collaboration at CERN LEP. We find that the bounds are almost independent of the mixing angle $\phi$ of the model in the allowed experimental range for this parameter. In addition, the analytical and numerical results for the cross-section have never been reported in the literature before.