ISSN:
1063-7788
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The Mainz neutrino-mass experiment investigates the endpoint region of the tritium β-decay spectrum with a MAC-E spectrometer to determine the mass of the electron antineutrino. By the recent upgrade, the former problem of dewetting T2 films has been solved, and the signal-to-background ratio was improved by a factor of 10. The latest measurement leads to $$m_\nu ^2 = - 3.7 \pm 5.3(stat.) \pm 2.1(syst.){{eV^2 } \mathord{\left/ {\vphantom {{eV^2 } {c^4 }}} \right. \kern-\nulldelimiterspace} {c^4 }}$$ , from which an upper limit of $$m_\nu 〈 2.8{{eV^2 } \mathord{\left/ {\vphantom {{eV^2 } {c^2 }}} \right. \kern-\nulldelimiterspace} {c^2 }}(95\% C.L.)$$ is derived. Some indication for the anomaly, reported by the Troitsk group, was found, but its postulated half-year period is contradicted by our data. To push the sensitivity on the neutrino mass below 1 eV/c 2, a new larger MAC-E spectrometer is proposed. Besides its integrating mode, it could run in a new nonintegration operation MAC-E-TOF mode.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1134/1.855733
