Experiments set limits and a value for neutrino mass

Over thirty years ago the first real attempt to search experimentally for the electron neutrino mass was made by Geoffrey C. Hanna and Bruno Pontecorvo at Chalk River and by S. C. Curran and his collaborators at the University of Glasgow. They studied the end point of the tritium beta‐decay spectrum. Since then a number of experimenters have established upper limits on the mass of $νe$ from this spectrum.