https://doi.org/10.1140/epjc/s10052-021-08994-0
Regular Article – Experimental Physics
Search for long-lived particles decaying to 
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Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, Brazil
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Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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Center for High Energy Physics, Tsinghua University, Beijing, China
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School of Physics State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China
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University of Chinese Academy of Sciences, Beijing, China
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Institute Of High Energy Physics (IHEP), Beijing, China
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Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China
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Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IN2P3-LAPP, Annecy, France
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Université Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, France
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Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France
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Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
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LPNHE, Sorbonne Université, Paris Diderot Sorbonne Paris Cité, CNRS/IN2P3, Paris, France
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I. Physikalisches Institut, RWTH Aachen University, Aachen, Germany
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Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany
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Max-Planck-Institut für Kernphysik (MPIK), Heidelberg, Germany
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Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
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School of Physics, University College Dublin, Dublin, Ireland
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INFN Sezione di Bari, Bari, Italy
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INFN Sezione di Bologna, Bologna, Italy
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INFN Sezione di Ferrara, Ferrara, Italy
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INFN Sezione di Firenze, Florence, Italy
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INFN Laboratori Nazionali di Frascati, Frascati, Italy
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INFN Sezione di Genova, Genoa, Italy
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INFN Sezione di Milano-Bicocca, Milan, Italy
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INFN Sezione di Milano, Milan, Italy
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INFN Sezione di Cagliari, Monserrato, Italy
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Universita degli Studi di Padova, Universita e INFN, Padova, Padua, Italy
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INFN Sezione di Pisa, Pisa, Italy
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INFN Sezione di Roma Tor Vergata, Rome, Italy
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INFN Sezione di Roma La Sapienza, Rome, Italy
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Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands
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Nikhef National Institute for Subatomic Physics, VU University Amsterdam, Amsterdam, The Netherlands
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Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland
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Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Kraków, Poland
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National Center for Nuclear Research (NCBJ), Warsaw, Poland
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Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania
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Petersburg Nuclear Physics Institute NRC Kurchatov Institute (PNPI NRC KI), Gatchina, Russia
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Institute of Theoretical and Experimental Physics NRC Kurchatov Institute (ITEP NRC KI), Moscow, Russia
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Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia
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Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS), Moscow, Russia
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Yandex School of Data Analysis, Moscow, Russia
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Budker Institute of Nuclear Physics (SB RAS), Novosibirsk, Russia
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Institute for High Energy Physics NRC Kurchatov Institute (IHEP NRC KI), Protvino, Russia, Protvino, Russia
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ICCUB, Universitat de Barcelona, Barcelona, Spain
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Instituto Galego de Física de Altas Enerxías (IGFAE), Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Instituto de Fisica Corpuscular, Centro Mixto Universidad de Valencia-CSIC, Valencia, Spain
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European Organization for Nuclear Research (CERN), Geneva, Switzerland
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Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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Physik-Institut, Universität Zürich, Zurich, Switzerland
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NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine
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Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine
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University of Birmingham, Birmingham, UK
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H.H. Wills Physics Laboratory, University of Bristol, Bristol, UK
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Cavendish Laboratory, University of Cambridge, Cambridge, UK
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Department of Physics, University of Warwick, Coventry, UK
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STFC Rutherford Appleton Laboratory, Didcot, UK
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School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
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School of Physics and Astronomy, University of Glasgow, Glasgow, UK
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Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK
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Imperial College London, London, UK
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Department of Physics and Astronomy, University of Manchester, Manchester, UK
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Department of Physics, University of Oxford, Oxford, UK
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Massachusetts Institute of Technology, Cambridge, MA, USA
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University of Cincinnati, Cincinnati, OH, USA
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University of Maryland, College Park, MD, USA
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Los Alamos National Laboratory (LANL), Los Alamos, USA
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Syracuse University, Syracuse, NY, USA
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School of Physics and Astronomy, Monash University, Melbourne, Australia
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Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil
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Physics and Micro Electronic College, Hunan University, Changsha City, China
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Guangdong Provencial Key Laboratory of Nuclear Science, Institute of Quantum Matter, South China Normal University, Guangzhou, China
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School of Physics and Technology, Wuhan University, Wuhan, China
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Departamento de Fisica, Universidad Nacional de Colombia, Bogotá, Colombia
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Helmholtz-Institut für Strahlen und Kernphysik, Universität Bonn, Bonn, Germany
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Institut für Physik, Universität Rostock, Rostock, Germany
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INFN Sezione di Perugia, Perugia, Italy
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Van Swinderen Institute, University of Groningen, Groningen, The Netherlands
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Universiteit Maastricht, Maastricht, The Netherlands
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National Research Centre Kurchatov Institute, Moscow, Russia
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National University of Science and Technology “MISIS”, Moscow, Russia
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National Research University Higher School of Economics, Moscow, Russia
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National Research Tomsk Polytechnic University, Tomsk, Russia
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DS4DS, La Salle, Universitat Ramon Llull, Barcelona, Spain
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University of Michigan, Ann Arbor, USA
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Universidade Federal do Triângulo Mineiro (UFTM), Uberaba-MG, Brazil
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Laboratoire Leprince-Ringuet, Palaiseau, France
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P.N. Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow, Russia
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Università di Bari, Bari, Italy
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Università di Bologna, Bologna, Italy
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Università di Cagliari, Cagliari, Italy
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Università di Ferrara, Ferrara, Italy
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Università di Firenze, Firenze, Italy
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Università di Genova, Genova, Italy
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Università di Milano Bicocca, Milano, Italy
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Università di Roma Tor Vergata, Roma, Italy
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AGH - University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, Kraków, Poland
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Università di Padova, Padova, Italy
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Università di Pisa, Pisa, Italy
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Università degli Studi di Milano, Milano, Italy
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Università di Urbino, Urbino, Italy
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Università della Basilicata, Potenza, Italy
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Scuola Normale Superiore, Pisa, Italy
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Università di Modena e Reggio Emilia, Modena, Italy
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Università di Siena, Siena, Italy
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MSU - Iligan Institute of Technology (MSU-IIT), Iligan, Philippines
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Novosibirsk State University, Novosibirsk, Russia
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CERN, 1211, Geneva 23, Switzerland
zs
matthieu.marinangeli@gmail.com
Received:
7
December
2020
Accepted:
22
February
2021
Published online:
26
March
2021
Long-lived particles decaying to 
, with masses between 7 and 
and lifetimes between 2 and 
, are searched for by looking at displaced vertices containing electrons and muons of opposite charges. The search is performed using 
of 
collisions collected with the LHCb detector at a centre-of-mass energy of 
. Three mechanisms of production of long-lived particles are considered: the direct pair production from quark interactions, the pair production from the decay of a Standard-Model-like Higgs boson with a mass of 
, and the charged current production from an on-shell 
boson with an additional lepton. No evidence of these long-lived states is obtained and upper limits on the production cross-section times branching fraction are set on the different production modes.
© CERN for the benefit of the LHCb collaboration 2021
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