Direct neutrino-mass measurement based on 259 days of KATRIN data

• DOI: 10.1126/science.adq9592
• Publication Date: 2025-04-10T18:00:01Z
• Authors: 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 Khosonth...; 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 W. P. Poon; Jose Manuel Lopez...; Stefano Pozzi; Florian Priester; Jan Ráliš; Shivani Ramachandran; R. G. Hamish Robe...; 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 Sreetha...; 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
• Keywords: KATRIN

That neutrinos carry a nonvanishing rest mass is evidence of physics beyond the Standard Model elementary particles. Their absolute holds relevance in fields from particle to cosmology. We report on search for effective electron antineutrino with KATRIN experiment. performs precision spectroscopy tritium β-decay close kinematic endpoint. On basis first five measurement campaigns, we derived best-fit value <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>m</mml:mi> <mml:mi>ν</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> <mml:mo>=</mml:mo> <mml:mo>−</mml:mo> <mml:mn>0.14</mml:mn> </mml:mrow> <mml:mn>0.15</mml:mn> <mml:mo>+</mml:mo> <mml:mn>0.13</mml:mn> </mml:math> eV 2 , resulting an upper limit m ν &lt; 0.45 at 90% confidence level. Stemming 36 million electrons collected 259 days, substantial reduction background level, and improved systematic uncertainties, this result tightens KATRIN’s previous bound by factor almost two.