Sterile-neutrino search based on 259 days of KATRIN data

Neutrinos are the most abundant fundamental matter particles in the Universe and play a crucial part in particle physics and cosmology. Neutrino oscillation, discovered about 25 years ago, shows that the three known species mix with each other. Anomalous results from reactor and radioactive-source experiments<sup>1</sup> suggest a possible fourth neutrino state, the sterile neutrino, which does not interact through the weak force. The Karlsruhe Tritium Neutrino (KATRIN) experiment<sup>2</sup>, primarily designed to measure the neutrino mass using tritium β-decay, also searches for sterile neutrinos suggested by these anomalies. A sterile-neutrino signal would appear as a distortion in the β-decay energy spectrum, characterized by a discontinuity in curvature (kink) related to the sterile-neutrino mass. This signature, which depends only on the shape of the spectrum rather than its absolute normalization, offers a robust, complementary approach to reactor experiments. Here we report the analysis of the energy spectrum of 36 million tritium β-decay electrons recorded in 259 measurement days within the last 40 eV below the endpoint. The results exclude a substantial part of the parameter space suggested by the gallium anomaly and challenge the Neutrino-4 claim. Together with other neutrino-disappearance experiments, KATRIN probes sterile-to-active mass splittings from a fraction of an eV<sup>2</sup> to several hundred eV<sup>2</sup>, excluding light sterile neutrinos with mixing angles above a few per cent.

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Journal
Nature
Published
2025-12-03
DOI
https://doi.org/10.1038/s41586-025-09739-9
Citations
2
Primary Topic
Astrophysics and Cosmic Phenomena
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article
Field-Weighted Citation Impact
3.74

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article

Sterile-neutrino search based on 259 days of KATRIN data

J. Kohpeiß, A. Beglarian, S. Niemes, K. McMichael et al.
2 citations
Nature
Astrophysics and Cosmic Phenomena
3.74
article

Sterile-neutrino search based on 259 days of KATRIN data

J. Kohpeiß, A. Beglarian, S. Niemes, K. McMichael, Neven Kovač, B. Bornschein, S. Chilingaryan, D. Spreng, S. Schneidewind, K. Eitel, A. Felden, E. L. Martín, F. Glück, J. A. Formaggio, C. Rodenbeck, Christoph Wiesinger, S. Enomoto, O. Lebeda, K. Gauda, M. Steidl, J. Wydra, Heino Henke, Auttakit Chatrabhuti, Ann-Kathrin Schütz, L. Haßelmann, G. Zeller, Marco Carminati, R. Hiller, Kishan Habib, C. Melzer, Khanchai Khosonthongkee, Jan Ráliš, M. Machatschek, A. Kopmann, F. Simon, Y. Biondi, D. Hillesheimer, D. Hinz, M. Pavan, M. Šefčík, L. Bornschein, F. M. Fränkle, Nicholas Tan Jerome, Caroline Fengler, I. Nutini, S. Ramachandran, J. F. Wilkerson, Daniel Siegmann, O. Dragoun, Thanh-Long Le, Udomsilp Pinsook, Imke Müller, D. Díaz Barrero, J. Wolf, M. Röllig, S. Mertens, Robin Größle, D. Batzler, K. Helbing, W. Gil, T. Thuemmler, J. Lauer, M. Aker, Magnus Schlösser, A.W.P. Poon, J. Seeyangnok, Warintorn Sreethawong, A. Onillón, Adrian Schwenck, L. Schlüter, R. Engel, B. Bieringer, J. Štorek, Matthias Böttcher, Alejandro Sáenz, F. Edzards, L. Köllenberger, M. Descher, B. Lehnert, V. Hannen, K. Valerius, Carlo Ettore Fiorini, Alexey Lokhov, D. S. Parno, A. Marsteller, J. Schürmann, U. Schnurr, X. Stribl, S. Heyns, J. Beisenkötter, Shailaja Mohanty, G. Gagliardi, Anna Gavin, L. A. Thorne, K. Urban, M. Biassoni, Christian Forstner, Bruno Daniel, Helmut H. Telle, N. A. Titov, W. L. Xu, Holger Neumann, Rudolf Sack, Christian Weinheimer, S. Welte, J. M. L. Poyato, G. Drexlin, Christoph Köhler, Luisa La Cascio, D. Vénos, Thierry Lasserre, A. Nava, Florian Priester, J. Mostafa, Thomas Höhn, Sascha Wüstling, Igor Tkachev, Himal Acharya, J. Wendel, Julanan Songwadhana, R. Salomon, S. Zadoroghny, Peter Schäfer, Felix Spanier, A. Jansen, R. G. H. Robertson, Enrico Ellinger, M. Sturm, Alessandro Schwemmer, N. Suwonjandee, K. Trost, L. Laschinger, J. Plößner, L. Fallböhmer, L. E. Mettler
article en
2 citations

Abstract

Neutrinos are the most abundant fundamental matter particles in the Universe and play a crucial part in particle physics and cosmology. Neutrino oscillation, discovered about 25 years ago, shows that the three known species mix with each other. Anomalous results from reactor and radioactive-source experiments<sup>1</sup> suggest a possible fourth neutrino state, the sterile neutrino, which does not interact through the weak force. The Karlsruhe Tritium Neutrino (KATRIN) experiment<sup>2</sup>, primarily designed to measure the neutrino mass using tritium β-decay, also searches for sterile neutrinos suggested by these anomalies. A sterile-neutrino signal would appear as a distortion in the β-decay energy spectrum, characterized by a discontinuity in curvature (kink) related to the sterile-neutrino mass. This signature, which depends only on the shape of the spectrum rather than its absolute normalization, offers a robust, complementary approach to reactor experiments. Here we report the analysis of the energy spectrum of 36 million tritium β-decay electrons recorded in 259 measurement days within the last 40 eV below the endpoint. The results exclude a substantial part of the parameter space suggested by the gallium anomaly and challenge the Neutrino-4 claim. Together with other neutrino-disappearance experiments, KATRIN probes sterile-to-active mass splittings from a fraction of an eV<sup>2</sup> to several hundred eV<sup>2</sup>, excluding light sterile neutrinos with mixing angles above a few per cent.

NatureVol. 648(8092)
Karlsruhe Institute of Technology (DE), University of North Carolina at Chapel Hill (US), Oak Ridge National Laboratory (US), Lawrence Berkeley National Laboratory (US), Chulalongkorn University (TH), University of Wuppertal (DE), Duke University (US), Johannes Gutenberg University Mainz (DE), University of Washington (US), Université Paris Cité (FR), Heidelberg University (DE), University of Münster (DE), Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR), Université Paris-Saclay (FR), Laboratoire AstroParticule et Cosmologie (FR), Washington and Jefferson College (US), Humboldt-Universität zu Berlin (DE), Triangle Universities Nuclear Laboratory (US), Institute for Nuclear Research (RU), CEA Paris-Saclay (FR), Institut National de Physique Nucléaire et de Physique des Particules (FR), Istituto Nazionale di Fisica Nucleare, Sezione di Milano (IT), Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca (IT), Czech Academy of Sciences, Nuclear Physics Institute (CZ), Max Planck Institute for Nuclear Physics (DE), Institut de Recherche sur les Lois Fondamentales de l'Univers (FR), Technical University of Munich (DE), Universidad Autónoma de Madrid (ES), Massachusetts Institute of Technology (US), University of Milano-Bicocca (IT), Heidelberg Institute for Theoretical Studies (DE), Carnegie Mellon University (US), Suranaree University of Technology (TH), Politecnico di Milano (IT)
U.S. Department of Energy, National Energy Research Scientific Computing Center, European Commission, Deutscher Akademischer Austauschdienst, Deutsche Forschungsgemeinschaft, Bundesministerium für Bildung und Forschung, Max-Planck-Gesellschaft, Istituto Nazionale di Fisica Nucleare, Karlsruhe School of Elementary Particle and Astroparticle Physics: Science and Technology, Karlsruhe Institute of Technology, Lawrence Berkeley National Laboratory
Openalex Percentile: Top 7%
Astrophysics and Cosmic Phenomena
3.74
DOIOpen Access PDFOpenAlex
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