Abstract
The NA62 experiment at CERN, designed to study the ultra-rare decay K+ → π+\( \nu \overline{\nu} \), has also collected data in beam-dump mode. In this configuration, dark photons may be produced by protons dumped on an absorber and reach a decay volume beginning 80 m downstream. A search for dark photons decaying in flight to μ+μ− pairs is reported, based on a sample of 1.4 × 1017 protons on dump collected in 2021. No evidence for a dark photon signal is observed. A region of the parameter space is excluded at 90% CL, improving on previous experimental limits for dark photon masses between 215 and 550 MeV/c2.
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Acknowledgments
It is a pleasure to express our appreciation to the staff of the CERN laboratory and the technical staff of the participating laboratories and universities for their efforts in the operation of the experiment and data processing.
The cost of the experiment and its auxiliary systems was supported by the funding agencies of the Collaboration Institutes. We are particularly indebted to: F.R.S.-FNRS (Fonds de la Recherche Scientifique — FNRS), under Grants No. 4.4512.10, 1.B.258.20, Belgium; CECI (Consortium des Equipements de Calcul Intensif), funded by the Fonds de la Recherche Scientifique de Belgique (F.R.S.-FNRS) under Grant No. 2.5020.11 and by the Walloon Region, Belgium; NSERC (Natural Sciences and Engineering Research Council), funding SAPPJ-2018-0017, Canada; MEYS (Ministry of Education, Youth and Sports) funding LM 2018104, Czech Republic; BMBF (Bundesministerium für Bildung und Forschung) contracts 05H12UM5, 05H15UMCNA and 05H18UMCNA, Germany; INFN (Istituto Nazionale di Fisica Nucleare), Italy; MIUR (Ministero dell’Istruzione, dell’Università e della Ricerca), Italy; CONACyT (Consejo Nacional de Ciencia y Tecnología), Mexico; IFA (Institute of Atomic Physics) Romanian CERN-RO Nr. 10/10.03.2020 and Nucleus Programme PN 19 06 01 04, Romania; MESRS (Ministry of Education, Science, Research and Sport), Slovakia; CERN (European Organization for Nuclear Research), Switzerland; STFC (Science and Technology Facilities Council), United Kingdom; NSF (National Science Foundation) Award Numbers 1506088 and 1806430, U.S.A.; ERC (European Research Council) “UniversaLepto” advanced grant 268062, “KaonLepton” starting grant 336581, Europe.
Individuals have received support from: Charles University Research Center (UNCE/SCI/013), Czech Republic; Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR “Futuro in ricerca 2012” grant RBFR12JF2Z, Project GAP), Italy; the Royal Society (grants UF100308, UF0758946), United Kingdom; STFC (Rutherford fellowships ST/J00412X/1, ST/M005798/1), United Kingdom; ERC (grants 268062, 336581 and starting grant 802836 “AxScale”); EU Horizon 2020 (Marie Skłodowska-Curie grants 701386, 754496, 842407, 893101, 101023808).
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A. Baeva, D. Baigarashev, D. Emelyanov, T. Enik, V. Falaleev, S. Fedotov, K. Gorshanov, E. Gushchin, V. Kekelidze, D. Kereibay, S. Kholodenko, A. Khotyantsev, A. Korotkova, Y. Kudenko, V. Kurochka, V. Kurshetsov, L. Litov, D. Madigozhin, A. Mefodev, M. Misheva, N. Molokanova, V. Obraztsov, A. Okhotnikov, I. Polenkevich, Yu. Potrebenikov, A. Sadovskiy, S. Shkarovskiy, V. Sugonyaev, O. Yushchenko are affiliated with an Institute or an international laboratory covered by a cooperation agreement with CERN
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The NA62 collaboration., Cortina Gil, E., Jerhot, J. et al. Search for dark photon decays to μ+μ− at NA62. J. High Energ. Phys. 2023, 35 (2023). https://doi.org/10.1007/JHEP09(2023)035
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DOI: https://doi.org/10.1007/JHEP09(2023)035