Evidence against manifest right-handed currents in neutron beta decay

Abstract

The bounds and presence of manifest right-handed currents in neutron beta decay are reviewed. Assuming the unitarity of the Cabibbo-Kobayashi-Maskawa matrix, the current experimental situation imposes very stringent limits on the mixing angle, $\ensuremath{-}0.000\text{ }77<\ensuremath{\zeta}<0.000\text{ }89$, and on the mass eigenstate, ${M}_{2}\text{ }\text{ }(\mathrm{GeV})\ensuremath{\in}(291.4,439.9)$, in contradiction with the established lower bound on ${M}_{2}$.