Eur. Phys. J. C (2021) 81: 451
https://doi.org/10.1140/epjc/s10052-021-09224-3

Regular Article - Experimental Physics

Sensitivity of the SHiP experiment to dark photons decaying to a pair of charged particles

¹ Faculty of Physics, Sofia University, Sofia, Bulgaria
² Universidad Técnica Federico Santa María and Centro Científico Tecnológico de Valparaíso, Valparaiso, Chile
³ Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
⁴ LAL, Univ. Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, Orsay, France
⁵ LPNHE, IN2P3/CNRS, Sorbonne Université, Université Paris Diderot, 75252, Paris, France
⁶ Humboldt-Universität zu Berlin, Berlin, Germany
⁷ Physikalisches Institut, Universität Bonn, Bonn, Germany
⁸ Universität Hamburg, Hamburg, Germany
⁹ Forschungszentrum Jülich GmbH (KFA), Jülich, Germany
¹⁰ Institut für Physik and PRISMA Cluster of Excellence, Johannes Gutenberg Universität Mainz, Mainz, Germany
¹¹ Sezione INFN di Bari, Bari, Italy
¹² Sezione INFN di Bologna, Bologna, Italy
¹³ Sezione INFN di Cagliari, Cagliari, Italy
¹⁴ Sezione INFN di Napoli, Naples, Italy
¹⁵ Laboratori Nazionali dell’INFN di Frascati, Frascati, Italy
¹⁶ Laboratori Nazionali dell’INFN di Gran Sasso, L’Aquila, Italy
¹⁷ Aichi University of Education, Kariya, Japan
¹⁸ Kobe University, Kobe, Japan
¹⁹ Nagoya University, Nagoya, Japan
²⁰ College of Industrial Technology, Nihon University, Narashino, Japan
²¹ Toho University, Funabashi, Chiba, Japan
²² Physics Education Department and RINS, Gyeongsang National University, Jinju, Korea
²³ Gwangju National University of Education, Gwangju, Korea
²⁴ Jeju National University, Jeju, Korea
²⁵ Korea University, Seoul, Korea
²⁶ Sungkyunkwan University, Suwon-si, Gyeong Gi-do, Korea
²⁷ University of Leiden, Leiden, The Netherlands
²⁸ LIP, Laboratory of Instrumentation and Experimental Particle Physics, Lisbon, Portugal
²⁹ Joint Institute for Nuclear Research (JINR), Dubna, Russia
³⁰ Institute of Theoretical and Experimental Physics (ITEP) NRC “Kurchatov Institute”, Moscow, Russia
³¹ Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), Moscow, Russia
³² P.N. Lebedev Physical Institute (LPI RAS), Moscow, Russia
³³ National Research Centre “Kurchatov Institute”, Moscow, Russia
³⁴ National University of Science and Technology “MISiS”, Moscow, Russia
³⁵ Institute for High Energy Physics (IHEP) NRC “Kurchatov Institute”, Protvino, Russia
³⁶ Petersburg Nuclear Physics Institute (PNPI) NRC “Kurchatov Institute”, Gatchina, Russia
³⁷ St. Petersburg Polytechnic University (SPbPU), St. Petersburg, Russia
³⁸ National Research Nuclear University (MEPhI), Moscow, Russia
³⁹ Skobeltsyn Institute of Nuclear Physics of Moscow State University (SINP MSU), Moscow, Russia
⁴⁰ Yandex School of Data Analysis, Moscow, Russia
⁴¹ Institute of Physics, University of Belgrade, Belgrade, Serbia
⁴² Stockholm University, Stockholm, Sweden
⁴³ Uppsala University, Uppsala, Sweden
⁴⁴ European Organization for Nuclear Research (CERN), Geneva, Switzerland
⁴⁵ University of Geneva, Geneva, Switzerland
⁴⁶ École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
⁴⁷ Physik-Institut, Universität Zürich, Zurich, Switzerland
⁴⁸ Middle East Technical University (METU), Ankara, Turkey
⁴⁹ Ankara University, Ankara, Turkey
⁵⁰ H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
⁵¹ STFC Rutherford Appleton Laboratory, Didcot, UK
⁵² Imperial College London, London, UK
⁵³ University College London, London, UK
⁵⁴ University of Warwick, Warwick, UK
⁵⁵ Taras Shevchenko National University of Kyiv, Kiev, Ukraine
⁵⁶ Università di Bari, Bari, Italy
⁵⁷ Università di Bologna, Bologna, Italy
⁵⁸ Università di Cagliari, Cagliari, Italy
⁵⁹ Università di Napoli “Federico II”, Naples, Italy
⁶⁰ Associated to Gyeongsang National University, Jinju, Korea
⁶¹ Associated to Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia
⁶² Moscow Institute of Physics and Technology (MIPT), Moscow Region, Russia
⁶³ Consorzio CREATE, Naples, Italy
⁶⁴ Università della Basilicata, Potenza, Italy
⁶⁵ Università di Napoli Parthenope, Naples, Italy
⁶⁶ Faculty of Physics M.V. Lomonosov Moscow State University, Moscow, Russia

^a a.magnan@imperial.ac.uk

Received: 11 November 2020
Accepted: 10 May 2021
Published online: 25 May 2021

Abstract

Dark photons are hypothetical massive vector particles that could mix with ordinary photons. The simplest theoretical model is fully characterised by only two parameters: the mass of the dark photon m${}_{{\gamma }^{\mathrm{D}}}$ and its mixing parameter with the photon, $\epsilon$. The sensitivity of the SHiP detector is reviewed for dark photons in the mass range between 0.002 and 10 GeV. Different production mechanisms are simulated, with the dark photons decaying to pairs of visible fermions, including both leptons and quarks. Exclusion contours are presented and compared with those of past experiments. The SHiP detector is expected to have a unique sensitivity for m${}_{{\gamma }^{\mathrm{D}}}$ ranging between 0.8 and 3.3${}_{-0.5}^{+0.2}$ GeV, and ${\epsilon }^2$ ranging between ${10}^{-11}$ and ${10}^{-17}$.