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First Search for Dark Sector e+e− Explanations of the MiniBooNE Anomaly at MicroBooNE

A. M. Abdullahi19, P. Abratenko46, D. Andrade Aldana17, L. Arellano28, J. Asaadi45, A. Ashkenazi44, S. Balasubramanian14, B. Baller14, A. Barnard36 et al. (MicroBooNE Collaboration)

A. Barnard36, G. Barr36, D. Barrow36, J. Barrow32, V. Basque14, J. Bateman18,28, O. Benevides Rodrigues17, S. Berkman31, A. Bhat9, M. Bhattacharya14, M. Bishai3, A. Blake24, B. Bogart30, T. Bolton23, M. B. Brunetti22,48, L. Camilleri12, D. Caratelli5, F. Cavanna14, G. Cerati14, A. Chappell48, Y. Chen40, J. M. Conrad29, M. Convery40, L. Cooper-Troendle37, J. I. Crespo-Anadón8, R. Cross48, M. Del Tutto14, S. R. Dennis6, P. Detje6, R. Diurba2, Z. Djurcic1, K. Duffy36, S. Dytman37, B. Eberly42, P. Englezos39, A. Ereditato9,14, J. J. Evans28, C. Fang5, W. Foreman17,25, B. T. Fleming9, D. Franco9, A. P. Furmanski32, F. Gao5, D. Garcia-Gamez15, S. Gardiner14, G. Ge12, S. Gollapinni25, E. Gramellini28, P. Green36, H. Greenlee14, L. Gu24, W. Gu3, R. Guenette28, P. Guzowski28, L. Hagaman9, M. D. Handley6, O. Hen29, C. Hilgenberg32, J. Hoefken Zink4,34, G. A. Horton-Smith23, M. Hostert16, A. Hussain23, B. Irwin32, M. S. Ismail37, C. James14, X. Ji33, J. H. Jo3, R. A. Johnson10, D. Kalra12, G. Karagiorgi12, W. Ketchum14, M. Kirby3, T. Kobilarcik14, N. Lane18,28, J.-Y. Li13, Y. Li3, K. Lin39, B. R. Littlejohn17, L. Liu14, W. C. Louis25, X. Luo5, T. Mahmud24, N. Majeed23, C. Mariani47, J. Marshall48, N. Martinez23, D. A. Martinez Caicedo41, S. Martynenko3, D. Massaro7,4,27, A. Mastbaum39, I. Mawby24, N. McConkey38, L. Mellet31, J. Mendez26, J. Micallef29,46, A. Mogan11, T. Mohayai20, M. Mooney11, A. F. Moor6, C. D. Moore14, L. Mora Lepin28, M. M. Moudgalya28, S. Mulleriababu2, D. Naples37, A. Navrer-Agasson18, N. Nayak3, M. Nebot-Guinot13, C. Nguyen39, J. Nowak24, N. Oza12, O. Palamara14, N. Pallat32, V. Paolone37, A. Papadopoulou1, V. Papavassiliou35, S. Pascoli4,21, H. B. Parkinson13, S. F. Pate35, N. Patel24, Z. Pavlovic14, E. Piasetzky44, K. Pletcher31, I. Pophale24, X. Qian3, J. L. Raaf14, V. Radeka3, A. Rafique1, M. Reggiani-Guzzo13, J. Rodriguez Rondon41, M. Rosenberg46, M. Ross-Lonergan25, I. Safa12, D. W. Schmitz9, A. Schukraft14, W. Seligman12, M. H. Shaevitz12, R. Sharankova14, J. Shi6, E. L. Snider14, M. Soderberg43, S. Söldner-Rembold18, J. Spitz30, M. Stancari14, J. St. John14, T. Strauss14, A. M. Szelc13, N. Taniuchi6, K. Terao40, C. Thorpe28, D. Torbunov3, D. Totani5, M. Toups14, A. Trettin28, Y.-T. Tsai40, J. Tyler23, M. A. Uchida6, T. Usher40, B. Viren3, J. Wang33, M. Weber2, H. Wei26, A. J. White9, S. Wolbers14, T. Wongjirad46, K. Wresilo6, W. Wu37, E. Yandel5,25, T. Yang14, L. E. Yates14, H. W. Yu3, G. P. Zeller14, J. Zennamo14, and C. Zhang3 (MicroBooNE Collaboration)

  • 1Argonne National Laboratory (ANL), Lemont, Illinois 60439, USA
  • 2Universität Bern, Bern CH-3012, Switzerland
  • 3Brookhaven National Laboratory (BNL), Upton, New York 11973, USA
  • 4Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy
  • 5University of California, Santa Barbara, California 93106, USA
  • 6University of Cambridge, Cambridge CB3 0HE, United Kingdom
  • 7Information Technology Department, CERN, 1211 Geneva 23, Switzerland
  • 8Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid E-28040, Spain
  • 9University of Chicago, Chicago, Illinois 60637, USA
  • 10University of Cincinnati, Cincinnati, Ohio 45221, USA
  • 11Colorado State University, Fort Collins, Colorado 80523, USA
  • 12Columbia University, New York, New York 10027, USA
  • 13University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
  • 14Fermi National Accelerator Laboratory (FNAL), Batavia, Illinois 60510, USA
  • 15Universidad de Granada, Granada E-18071, Spain
  • 16Harvard University, Cambridge, Massachusetts 02138, USA
  • 17Illinois Institute of Technology (IIT), Chicago, Illinois 60616, USA
  • 18Imperial College London, London SW7 2AZ, United Kingdom
  • 19Instituto de Fisica Teorica (IFT), Madrid E-28049, Spain
  • 20Indiana University, Bloomington, Indiana 47405, USA
  • 21INFN, Sezione di Bologna, Bologna, Italy
  • 22The University of Kansas, Lawrence, Kansas 66045, USA
  • 23Kansas State University (KSU), Manhattan, Kansas 66506, USA
  • 24Lancaster University, Lancaster LA1 4YW, United Kingdom
  • 25Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545, USA
  • 26Louisiana State University, Baton Rouge, Louisiana 70803, USA
  • 27Centre for Cosmology, Particle Physics and Phenomenology—CP3, Université catholique de Louvain, Louvain-la-Neuve, Belgium
  • 28The University of Manchester, Manchester M13 9PL, United Kingdom
  • 29Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
  • 30University of Michigan, Ann Arbor, Michigan 48109, USA
  • 31Michigan State University, East Lansing, Michigan 48824, USA
  • 32University of Minnesota, Minneapolis, Minnesota 55455, USA
  • 33Nankai University, Nankai District, Tianjin 300071, China
  • 34National Centre for Nuclear Research, ul. Pasteura 7, 02-093 Warsaw, Poland
  • 35New Mexico State University (NMSU), Las Cruces, New Mexico 88003, USA
  • 36University of Oxford, Oxford OX1 3RH, United Kingdom
  • 37University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
  • 38Queen Mary University of London, London E1 4NS, United Kingdom
  • 39Rutgers University, Piscataway, New Jersey 08854, USA
  • 40SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
  • 41South Dakota School of Mines and Technology (SDSMT), Rapid City, South Dakota 57701, USA
  • 42University of Southern Maine, Portland, Maine 04104, USA
  • 43Syracuse University, Syracuse, New York 13244, USA
  • 44Tel Aviv University, Tel Aviv, Israel, 69978
  • 45University of Texas, Arlington, Texas 76019, USA
  • 46Tufts University, Medford, Massachusetts 02155, USA
  • 47Center for Neutrino Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
  • 48University of Warwick, Coventry CV4 7AL, United Kingdom

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Phys. Rev. Lett. 136, 121804 – Published 27 March, 2026

DOI: https://doi.org/10.1103/3q7x-ks7h

Abstract

We present MicroBooNE’s first search for dark sector e+e− explanations of the long-standing MiniBooNE anomaly. The MiniBooNE anomaly has garnered significant attention over the past 20 years including previous MicroBooNE investigations into both anomalous electron and photon excesses, but its origin still remains unclear. In this Letter, we provide the first direct test of dark sector models in which dark neutrinos, produced through neutrino-induced scattering, decay into missing energy and visible e+e− pairs comprising the MiniBooNE anomaly. Many such models have recently gained traction as a viable solution to the anomaly while evading past bounds. Using an exposure of 6.87×1020 protons-on-target in the Booster Neutrino Beam, we implement a selection targeting forward-going, coherently produced e+e− events. After unblinding, we observe 95 events, which we compare with the constrained background-only prediction of 69.7±17.3. This analysis sets the world’s first direct limits on these dark sector models and, at the 95% confidence level, excludes the entirety of the single dark neutrino and majority of the dual dark neutrino, parameter space that is viable as a solution to the MiniBooNE anomaly.

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Phys. Rev. Lett. 136, 121804– Published 27 March, 2026
  • Received 19 March 2025
  • Revised 27 October 2025
  • Accepted 17 December 2025
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