Analysis methods for the first KATRIN neutrino-mass measurement

0544123 - ÚJF 2022 RIV US eng J - Journal Article
Aker, M. - Altenmuller, K. - Beglarian, A. - Behrens, J. - Dragoun, Otokar - Kovalík, Alojz - Lebeda, Ondřej - Ryšavý, Miloš - Šefčík, Michal - Vénos, Drahoslav … Total 129 authors
Analysis methods for the first KATRIN neutrino-mass measurement.
Physical Review D. Roč. 104, č. 1 (2021), č. článku 012005. ISSN 2470-0010. E-ISSN 2470-0029
R&D Projects: GA MŠMT LTT19005
Research Infrastructure: CANAM II - 90056
Institutional support: RVO:61389005
Keywords : KATRIN * neutrino mass * beta-decay
OECD category: Particles and field physics
Impact factor: 5.407, year: 2021
Method of publishing: Open access
https://doi.org/10.1103/PhysRevD.104.012005

We report on the dataset, data handling, and detailed analysis techniques of the first neutrino-mass measurement by the Karlsruhe Tritium Neutrino (KATRIN) experiment, which probes the absolute neutrino-mass scale via the beta-decay kinematics of molecular tritium. The source is highly pure, cryogenic T-2 gas. The beta electrons are guided along magnetic field lines toward a high-resolution, integrating spectrometer for energy analysis. A silicon detector counts beta electrons above the energy threshold of the spectrometer, so that a scan of the thresholds produces a precise measurement of the high-energy spectral tail. After detailed theoretical studies, simulations, and commissioning measurements, extending from the molecular final-state distribution to inelastic scattering in the source to subtleties of the electromagnetic fields, our independent, blind analyses allow us to set an upper limit of 1.1 eVon the neutrino-mass scale at a 90% confidence level. This first result, based on a few weeks of running at a reduced source intensity and dominated by statistical uncertainty, improves on prior limits by nearly a factor of two. This result establishes an analysis framework for future KATRIN measurements, and provides important input to both particle theory and cosmology.
Permanent Link: http://hdl.handle.net/11104/0321172