Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN

• Published in: Physical review letters 2019-11, Vol.123 (22), p.221802-221802, Article 221802
• Main Authors: Aker, M, Altenmüller, K, Arenz, M, Babutzka, M, Barrett, J, Bauer, S, Beck, M, Beglarian, A, Behrens, J, Bergmann, T, Besserer, U, Blaum, K, Block, F, Bobien, S, Bokeloh, K, Bonn, J, Bornschein, B, Bornschein, L, Bouquet, H, Brunst, T, Caldwell, T S, La Cascio, L, Chilingaryan, S, Choi, W, Corona, T J, Debowski, K, Deffert, M, Descher, M, Doe, P J, Dragoun, O, Drexlin, G, Dunmore, J A, Dyba, S, Edzards, F, Eisenblätter, L, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Erhard, M, Eversheim, D, Fedkevych, M, Felden, A, Fischer, S, Flatt, B, Formaggio, J A, Fränkle, F M, Franklin, G B, Frankrone, H, Friedel, F, Fuchs, D, Fulst, A, Furse, D, Gauda, K, Gemmeke, H, Gil, W, Glück, F, Görhardt, S, Groh, S, Grohmann, S, Grössle, R, Gumbsheimer, R, Ha Minh, M, Hackenjos, M, Hannen, V, Harms, F, Hartmann, J, Haußmann, N, Heizmann, F, Helbing, K, Hickford, S, Hilk, D, Hillen, B, Hillesheimer, D, Hinz, D, Höhn, T, Holzapfel, B, Holzmann, S, Houdy, T, Howe, M A, Huber, A, James, T M, Jansen, A, Kaboth, A, Karl, C, Kazachenko, O, Kellerer, J, Kernert, N, Kippenbrock, L, Kleesiek, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kosmider, A, Kovalík, A, Krasch, B, Kraus, M, Krause, H
• Format: Article
• Language: English
• Subjects: Astrophysics; Beta decay; Confidence intervals; High Energy Physics - Experiment; Instrumentation and Detectors; Kinematics; neutrino; neutrino mass; Neutrinos; Nuclear Experiment; NUCLEAR PHYSICS AND RADIATION PHYSICS; Physics; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Tritium
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.123.221802

We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9})  eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation.