1. Direct neutrino-mass measurement with sub-electronvolt sensitivity
- Author
-
Collaboration, The KATRIN, Aker, M., Beglarian, A., Behrens, J., Berlev, A., Besserer, U., Bieringer, B., Block, F., Bobien, S., B��ttcher, M., Bornschein, B., Bornschein, L., Brunst, T., Caldwell, T. S., Carney, R. M. D., La Cascio, L., Chilingaryan, S., Choi, W., Debowski, K., Deffert, M., Descher, M., D��az Barrero, D., Doe, P. J., Dragoun, O., Drexlin, G., Eitel, K., Ellinger, E., Engel, R., Enomoto, S., Felden, A., Formaggio, J. A., Fr��nkle, F. M., Franklin, G. B., Friedel, F., Fulst, A., Gauda, K., Gil, W., Gl��ck, F., Gr��ssle, R., Gumbsheimer, R., Gupta, V., H��hn, T., Hannen, V., Hau��mann, N., Helbing, K., Hickford, S., Hiller, R., Hillesheimer, D., Hinz, D., Houdy, T., Huber, A., Jansen, A., Karl, C., Kellerer, F., Kellerer, J., Kleifges, M., Klein, M., K��hler, C., K��llenberger, L., Kopmann, A., Korzeczek, M., Koval��k, A., Krasch, B., Krause, H., Kunka, N., Lasserre, T., Le, T. L., Lebeda, O., Lehnert, B., Lokhov, A., Machatschek, M., Malcherek, E., Mark, M., Marsteller, A., Martin, E. L., Melzer, C., Menshikov, A., Mertens, S., Mostafa, J., M��ller, K., Neumann, H., Niemes, S., Oelpmann, P., Parno, D. S., Poon, A. W. P., Poyato, J. M. L., Priester, F., Ramachandran, S., Robertson, R. G. H., Rodejohann, W., R��llig, M., R��ttele, C., Rodenbeck, C., Ry��av��, M., Sack, R., Saenz, A., Sch��fer, P., Schaller N��e Pollithy, A., Schimpf, L., Schl��sser, K., Schl��sser, M., Schl��ter, L., Schneidewind, S., Schrank, M., Schulz, B., Schwemmer, A., ��ef����k, M., Sibille, V., Siegmann, D., Slez��k, M., Spanier, F., Steidl, M., Sturm, M., Sun, M., Tcherniakhovski, D., Telle, H. H., Thorne, L. A., Th��mmler, T., Titov, N., Tkachev, I., Urban, K., Valerius, K., V��nos, D., Vizcaya Hern��ndez, A. P., Weinheimer, C., Welte, S., Wendel, J., Wilkerson, J. F., Wolf, J., W��stling, S., Wydra, J., Xu, W., Yen, Y.-R., Zadoroghny, S., Zeller, G., AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and KATRIN
- Subjects
mass: scale ,tritium: semileptonic decay ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,electron: energy spectrum ,General Physics and Astronomy ,ddc:620 ,mass: upper limit ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,sensitivity ,KATRIN ,antineutrino/e: mass ,Engineering & allied operations ,experimental results - Abstract
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, mν, from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment, mν is probed via a high-precision measurement of the tritium β-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 mν of 0.7 eV c–2 at a 90% confidence level (CL). The best fit to the spectral data yields $${{\mbox{}}}{m}_{\nu }^{2}{{\mbox{}}}$$ m ν 2 = (0.26 ± 0.34) eV2 c–4, resulting in an upper limit of mν c–2 at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of mν c–2 at 90% CL.
- Published
- 2022