Abstract
We report the most sensitive direct upper limit set on the mass of the electron antineutrino. Our measurements of the shape of the β decay spectrum of free molecular tritium yield, under the assumption of no new physics other than that of mass, a central value for of -147±68±41 , which corresponds to an upper limit of 9.3 eV (95% confidence level) on . The result is in clear disagreement with a reported value of 26(5) eV.
- Received 6 May 1991
DOI:https://doi.org/10.1103/PhysRevLett.67.957
©1991 American Physical Society