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Challenging Spontaneous Quantum Collapse with the XENONnT Dark Matter Detector

E. Aprile1, J. Aalbers2, K. Abe3, S. Ahmed Maouloud4, L. Althueser5, B. Andrieu4, E. Angelino6,7, D. Antón Martin8, S. R. Armbruster9 et al. (XENON Collaboration)

S. R. Armbruster9, F. Arneodo10, L. Baudis11, M. Bazyk12, L. Bellagamba13, R. Biondi9,14, A. Bismark11,*, K. Boese9, A. Brown15, G. Bruno12, R. Budnik14, C. Cai16, C. Capelli11, J. M. R. Cardoso17, A. P. Cimental Chávez11, A. P. Colijn18, J. Conrad19, J. J. Cuenca-García11, V. D’Andrea7,†, L. C. Daniel Garcia4, M. P. Decowski18, A. Deisting20, C. Di Donato21,7, P. Di Gangi13, S. Diglio12, K. Eitel22, S. el Morabit18, A. Elykov22, A. D. Ferella21,7, C. Ferrari7, H. Fischer15, T. Flehmke19, M. Flierman18, W. Fulgione6,7, C. Fuselli18, P. Gaemers18, R. Gaior4, M. Galloway11, F. Gao16, S. Ghosh23, R. Giacomobono24, F. Girard4, R. Glade-Beucke15, L. Grandi8, J. Grigat15, H. Guan23, M. Guida9, P. Gyorgy20, R. Hammann9, A. Higuera25, C. Hils20, L. Hoetzsch9, N. F. Hood26, M. Iacovacci24, Y. Itow27, J. Jakob5, F. Joerg11, Y. Kaminaga3, M. Kara22, P. Kavrigin14, S. Kazama27, P. Kharbanda18, M. Kobayashi27, D. Koke5, A. Kopec26,‡, H. Landsman14, R. F. Lang23, L. Levinson14, I. Li25, S. Li28, S. Liang25, Z. Liang28, Y.-T. Lin9, S. Lindemann15, K. Liu16, M. Liu1,16, J. Loizeau12, F. Lombardi20, J. Long8, J. A. M. Lopes17,§, G. M. Lucchetti13, T. Luce15, Y. Ma26, C. Macolino21,7, J. Mahlstedt19, A. Mancuso13, L. Manenti10, F. Marignetti24, T. Marrodán Undagoitia9, K. Martens3, J. Masbou12, S. Mastroianni24, A. Melchiorre21,7, J. Merz20, M. Messina7, A. Michael5, K. Miuchi29, A. Molinario6, S. Moriyama3, K. Morå1, Y. Mosbacher14, M. Murra1, J. Müller15, K. Ni26, U. Oberlack20, B. Paetsch14, Y. Pan4, Q. Pellegrini4, R. Peres11, C. Peters25, J. Pienaar8,14, M. Pierre18, G. Plante1, T. R. Pollmann18, L. Principe12, J. Qi26, J. Qin25, D. Ramírez García11, M. Rajado11, A. Ravindran12, A. Razeto7, L. Redard-Jacot11, R. Singh23, L. Sanchez25, J. M. F. dos Santos17, I. Sarnoff10, G. Sartorelli13, J. Schreiner9, P. Schulte5, H. Schulze Eißing5, M. Schumann15, L. Scotto Lavina4, M. Selvi13, F. Semeria13, P. Shagin20, S. Shi1, J. Shi16, M. Silva17, H. Simgen9, A. Stevens15, C. Szyszka20, A. Takeda3, Y. Takeuchi29, P.-L. Tan19,1, D. Thers12, G. Trinchero6, C. D. Tunnell25, F. Tönnies15, K. Valerius22, S. Vecchi30, S. Vetter22, F. I. Villazon Solar20, G. Volta9, C. Weinheimer5, M. Weiss14, D. Wenz5, C. Wittweg11,∥, V. H. S. Wu22, Y. Xing12, D. Xu1, Z. Xu1, M. Yamashita3, L. Yang26, J. Ye31, L. Yuan8, G. Zavattini30, M. Zhong26, C. Curceanu32,33, S. Manti32, and K. Piscicchia34,32,** (XENON Collaboration)

  • 1Physics Department, Columbia University, New York, New York 10027, USA
  • 2Nikhef and the University of Groningen, Van Swinderen Institute, 9747AG Groningen, Netherlands
  • 3Kamioka Observatory, Institute for Cosmic Ray Research, and Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205, Japan
  • 4LPNHE, Sorbonne Université, CNRS/IN2P3, 75005 Paris, France
  • 5Institut für Kernphysik, University of Münster, 48149 Münster, Germany
  • 6INAF-Astrophysical Observatory of Torino, Department of Physics, University of Torino and INFN-Torino, 10125 Torino, Italy
  • 7INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L’Aquila, Italy
  • 8Department of Physics, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, Illinois 60637, USA
  • 9Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
  • 10New York University Abu Dhabi - Center for Astro, Particle and Planetary Physics, Abu Dhabi, United Arab Emirates
  • 11Physik-Institut, University of Zürich, 8057 Zürich, Switzerland
  • 12SUBATECH, IMT Atlantique, CNRS/IN2P3, Nantes Université, Nantes 44307, France
  • 13Department of Physics and Astronomy, University of Bologna and INFN-Bologna, 40126 Bologna, Italy
  • 14Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001, Israel
  • 15Physikalisches Institut, Universität Freiburg, 79104 Freiburg, Germany
  • 16Department of Physics & Center for High Energy Physics, Tsinghua University, Beijing 100084, People’s Republic of China
  • 17LIBPhys, Department of Physics, University of Coimbra, 3004-516 Coimbra, Portugal
  • 18Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam, Netherlands
  • 19Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, Stockholm SE-10691, Sweden
  • 20Institut für Physik & Exzellenzcluster PRISMA+, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
  • 21Department of Physics and Chemistry, University of L’Aquila, 67100 L’Aquila, Italy
  • 22Institute for Astroparticle Physics, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
  • 23Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
  • 24Department of Physics “Ettore Pancini,” University of Napoli and INFN-Napoli, 80126 Napoli, Italy
  • 25Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
  • 26Department of Physics, University of California San Diego, La Jolla, California 92093, USA
  • 27Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, and Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
  • 28Department of Physics, School of Science, Westlake University, Hangzhou 310030, People’s Republic of China
  • 29Department of Physics, Kobe University, Kobe, Hyogo 657-8501, Japan
  • 30INFN-Ferrara and Dip. di Fisica e Scienze della Terra, Università di Ferrara, 44122 Ferrara, Italy
  • 31School of Science and Engineering, The Chinese University of Hong Kong (Shenzhen), Shenzhen, Guangdong 518172, People’s Republic China
  • 32Laboratori Nazionali di Frascati, INFN, Frascati, Italy
  • 33IFIN-HH, Institutul National pentru Fizica si Inginerie Nucleara Horia Hulubei, Măgurele, Romania
  • 34Centro Ricerche Enrico Fermi—Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi,” Rome, Italy

  • *Contact author: alexander.bismark@physik.uzh.ch
  • †Also at INFN-Roma Tre, 00146 Roma, Italy.
  • ‡Present address: Department of Physics and Astronomy, Bucknell University, Lewisburg, Pennsylvania, USA.
  • §Also at Coimbra Polytechnic—ISEC, 3030-199 Coimbra, Portugal.
  • ∥Now at Imperial College London, Department of Physics, Blackett Laboratory, London SW7 2AZ, United Kingdom.
  • Contact author: xenon@lngs.infn.it
  • **Contact author: kristian.piscicchia@cref.it
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Phys. Rev. Lett. 136, 120201 – Published 23 March, 2026

DOI: https://doi.org/10.1103/2jm3-4976

Abstract

We report on the search for x-ray radiation as predicted from dynamical quantum collapse with low-energy electronic recoil data in the energy range of 1–140 keV from the first science run of the XENONnT dark matter detector. Spontaneous radiation is an unavoidable effect of dynamical collapse models, which were introduced as a possible solution to the long-standing measurement problem in quantum mechanics. The analysis utilizes a model that for the first time accounts for cancellation effects in the emitted spectrum, which arise in the x-ray range due to the opposing electron-proton charges in xenon atoms. New world-leading limits on the free parameters of the Markovian continuous spontaneous localization and Diósi-Penrose models are set, improving previous best constraints by two orders of magnitude and a factor of five, respectively. For the strength and correlation length of the continuous spontaneous localization model, values in the originally proposed parameter ranges are experimentally excluded for the first time.

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Phys. Rev. Lett. 136, 120201– Published 23 March, 2026
  • Received 16 June 2025
  • Accepted 22 January 2026
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