Bounds and presence of manifest right handed currents in neutron beta decay are reviewed. Assuming the unitarity of the Cabibbo-Kobayashi-Maskawa matrix, current experimental situation imposes very stringent limits on the mixing angle, −0.00077<ζ<0.00089, and on the mass eigenstate, M2(GeV)∈(291.4,439.9), in contradiction with the established lower bound on M2.
@article{arxiv.1006.5417,
title = {Evidence against manifest right-handed currents in neutron beta decay},
author = {A. Garcia and G. Sanchez-Colon},
journal= {arXiv preprint arXiv:1006.5417},
year = {2010}
}