Sterile-neutrino search based on 259 days of KATRIN data
Abstract
Neutrinos are the most abundant fundamental matter particles in the Universe and play a crucial role in particle physics and cosmology. Neutrino oscillation, discovered about 25 years ago, reveals that the three known species mix with each other. Anomalous results from reactor and radioactive-source experiments suggest a possible fourth neutrino state, the sterile neutrino, which does not interact via the weak force. The KATRIN experiment, primarily designed to measure the neutrino mass via tritium -decay, also searches for sterile neutrinos suggested by these anomalies. A sterile-neutrino signal would appear as a distortion in the -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. KATRIN examined the energy spectrum of 36 million tritium -decay electrons recorded in 259 measurement days within the last 40 electronvolt 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 electron-volt squared to several hundred electron-volts squared, excluding light sterile neutrinos with mixing angles above a few percent.
Keywords
Cite
@article{arxiv.2503.18667,
title = {Sterile-neutrino search based on 259 days of KATRIN data},
author = {Himal Acharya and Max Aker and Dominic Batzler and Armen Beglarian and Justus Beisenkötter and Matteo Biassoni and Benedikt Bieringer and Yanina Biondi and Matthias Böttcher and Beate Bornschein and Lutz Bornschein and Marco Carminati and Auttakit Chatrabhuti and Suren Chilingaryan and Deseada Díaz Barrero and Byron A. Daniel and Martin Descher and Otokar Dragoun and Guido Drexlin and Frank Edzards and Klaus Eitel and Enrico Ellinger and Ralph Engel and Sanshiro Enomoto and Luca Fallböhmer and Arne Felden and Caroline Fengler and Carlo Fiorini and Joseph A. Formaggio and Christian Forstner and Florian M. Fränkle and Giulio Gagliardi and Kevin Gauda and Andrew S. Gavin and Woosik Gil and Ferenc Glück and Robin Grössle and Thomas Höhn and Khushbakht Habib and Volker Hannen and Leonard Haßelmann and Klaus Helbing and Hanna Henke and Svenja Heyns and Roman Hiller and David Hillesheimer and Dominic Hinz and Alexander Jansen and Christoph Köhler and Khanchai Khosonthongkee and Joshua Kohpeiß and Leonard Köllenberger and Andreas Kopmann and Neven Kovač and Luisa La Cascio and Leo Laschinger and Thierry Lasserre and Joscha Lauer and Thanh-Long Le and Ondřej Lebeda and Bjoern Lehnert and Alexey Lokhov and Moritz Machatschek and Alexander Marsteller and Eric L. Martin and Kirsten McMichael and Christin Melzer and Lukas Erik Mettler and Susanne Mertens and Shailaja Mohanty and Jalal Mostafa and Immanuel Müller and Andrea Nava and Holger Neumann and Simon Niemes and Irene Nutini and Anthony Onillon and Diana S. Parno and Maura Pavan and Udomsilp Pinsook and Jan Plößner and Alan W. P. Poon and Jose Manuel Lopez Poyato and Florian Priester and Jan Ráliš and Marco Röllig and Shivani Ramachandran and R G. Hamish Robertson and Caroline Rodenbeck and Rudolf Sack and Alejandro Saenz and Richard Salomon and Jannis Schürmann and Peter Schäfer and Ann-Kathrin Schütz and Magnus Schlösser and Lisa Schlüter and Sonja Schneidewind and Ulrich Schnurr and Alessandro Schwemmer and Adrian Schwenck and Michal Šefčík and Jakkapat Seeyangnok and Daniel Siegmann and Frank Simon and Julanan Songwadhana and Felix Spanier and Daniela Spreng and Warintorn Sreethawong and Markus Steidl and Jaroslav Štorek and Xaver Stribl and Michael Sturm and Narumon Suwonjandee and Nicholas Tan Jerome and Helmut H. H. Telle and Thomas Thümmler and Larisa A. Thorne and Nikita Titov and Igor Tkachev and Kerstin Trost and Korbinian Urban and Drahoš Vénos and Kathrin Valerius and Sascha Wüstling and Christian Weinheimer and Stefan Welte and Jürgen Wendel and Christoph Wiesinger and John F. Wilkerson and Joachim Wolf and Johanna Wydra and Weiran Xu and Sergey Zadorozhny and Genrich Zeller},
journal= {arXiv preprint arXiv:2503.18667},
year = {2025}
}
Comments
37 pages, 16 figures