Direct neutrino-mass measurement with sub-electronvolt sensitivity

0554740 - ÚJF 2023 RIV DE eng J - Journal Article
Aker, M. - Beglarian, A. - Behrens, J. - Berlev, A. I. - Besserer, U. - Dragoun, Otokar - Kovalík, Alojz - Lebeda, Ondřej - Ryšavý, Miloš - Vénos, Drahoslav … Total 133 authors
Direct neutrino-mass measurement with sub-electronvolt sensitivity.
Nature Physics. Roč. 18, č. 2 (2022), s. 160-166. ISSN 1745-2473. E-ISSN 1745-2481
R&D Projects: GA MŠMT LTT19005
Research Infrastructure: CANAM II - 90056
Institutional support: RVO:61389005
Keywords : KATRIN * neutrinos * neutrino mass
OECD category: Particles and field physics
Impact factor: 19.5, year: 2022
Method of publishing: Open access
https://doi.org/10.1038/s41567-021-01463-1

Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, the absolute neutrino-mass scale remains unknown. Here we report the upper limits on effective electron anti-neutrino mass, m(nu), from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment, m(nu) is probed via a high-precision measurement of the tritium beta-decay spectrum close to its endpoint. This method is independent of any cosmological model and does not rely on assumptions whether the neutrino is a Dirac or Majorana particle. By increasing the source activity and reducing the background with respect to the first physics campaign, we reached a sensitivity on m(nu) of 0.7 eV c(-2) at a 90% confidence level (CL). The best fit to the spectral data yields m(nu)(2) = (0.26 +/- 0.34) eV(2) c(-4), resulting in an upper limit of m(nu) < 0.9 eV c(-2) at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of m(nu) < 0.8 eV c(-2) at 90% CL.
Permanent Link: http://hdl.handle.net/11104/0329401