Direct neutrino-mass measurement based on 259 days of KATRIN data.
Science (New York, N.Y.) 388:6743 (2025) 180-185
Authors:
KATRIN Collaboration†, Max Aker, Dominic Batzler, Armen Beglarian, Jan Behrens, Justus Beisenkötter, Matteo Biassoni, Benedikt Bieringer, Yanina Biondi, Fabian Block, Steffen Bobien, Matthias Böttcher, Beate Bornschein, Lutz Bornschein, Tom S Caldwell, Marco Carminati, Auttakit Chatrabhuti, Suren Chilingaryan, Byron A Daniel, Karol Debowski, Martin Descher, Deseada Díaz Barrero, Peter J Doe, Otokar Dragoun, Guido Drexlin, Frank Edzards, Klaus Eitel, Enrico Ellinger, Ralph Engel, Sanshiro Enomoto, Arne Felden, Caroline Fengler, Carlo Fiorini, Joseph A Formaggio, Christian Forstner, Florian M Fränkle, Kevin Gauda, Andrew S Gavin, Woosik Gil, Ferenc Glück, Steffen Grohmann, Robin Grössle, Rainer Gumbsheimer, Nathanael Gutknecht, Volker Hannen, Leonard Hasselmann, Norman Haußmann, Klaus Helbing, Hanna Henke, Svenja Heyns, Stephanie Hickford, Roman Hiller, David Hillesheimer, Dominic Hinz, Thomas Höhn, Anton Huber, Alexander Jansen, Christian Karl, Jonas Kellerer, Khanchai Khosonthongkee, Matthias Kleifges, Manuel Klein, Joshua Kohpeiß, Christoph Köhler, Leonard Köllenberger, Andreas Kopmann, Neven Kovač, Alojz Kovalík, Holger Krause, Luisa La Cascio, Thierry Lasserre, Joscha Lauer, Thanh-Long Le, Ondřej Lebeda, Bjoern Lehnert, Gen Li, Alexey Lokhov, Moritz Machatschek, Martin Mark, Alexander Marsteller, Eric L Martin, Christin Melzer, Susanne Mertens, Shailaja Mohanty, Jalal Mostafa, Klaus Müller, Andrea Nava, Holger Neumann, Simon Niemes, Anthony Onillon, Diana S Parno, Maura Pavan, Udomsilp Pinsook, Alan WP Poon, Jose Manuel Lopez Poyato, Stefano Pozzi, Florian Priester, Jan Ráliš, Shivani Ramachandran, RG Hamish Robertson, Caroline Rodenbeck, Marco Röllig, Carsten Röttele, Milos Ryšavý, Rudolf Sack, Alejandro Saenz, Richard Salomon, Peter Schäfer, Magnus Schlösser, Klaus Schlösser, Lisa Schlüter, Sonja Schneidewind, Ulrich Schnurr, Michael Schrank, Jannis Schürmann, Ann-Kathrin Schütz, Alessandro Schwemmer, Adrian Schwenck, Michal Šefčík, Daniel Siegmann, Frank Simon, Felix Spanier, Daniela Spreng, Warintorn Sreethawong, Markus Steidl, Jaroslav Štorek, Xaver Stribl, Michael Sturm, Narumon Suwonjandee, Nicholas Tan Jerome, Helmut H Telle, Larisa A Thorne, Thomas Thümmler, Simon Tirolf, Nikita Titov, Igor Tkachev, Korbinian Urban, Kathrin Valerius, Drahoslav Vénos, Christian Weinheimer, Stefan Welte, Jürgen Wendel, Christoph Wiesinger, John F Wilkerson, Joachim Wolf, Sascha Wüstling, Johanna Wydra, Weiran Xu, Sergey Zadorozhny, Genrich Zeller
Abstract:
That neutrinos carry a nonvanishing rest mass is evidence of physics beyond the Standard Model of elementary particles. Their absolute mass holds relevance in fields from particle physics to cosmology. We report on the search for the effective electron antineutrino mass with the KATRIN experiment. KATRIN performs precision spectroscopy of the tritium β-decay close to the kinematic endpoint. On the basis of the first five measurement campaigns, we derived a best-fit value of [Formula: see text] eV2, resulting in an upper limit of mν < 0.45 eV at 90% confidence level. Stemming from 36 million electrons collected in 259 measurement days, a substantial reduction of the background level, and improved systematic uncertainties, this result tightens KATRIN's previous bound by a factor of almost two.
