Hayrapetyan, A.Tumasyan, A.Adam, W.Andrejkovic, J. W.Bergauer, T.Chatterjee, S.Zhokin, A.2024-09-112024-09-1120242470-00102470-002910.1103/PhysRevD.110.0120042-s2.0-85199910657https://doi.org/10.1103/PhysRevD.110.012004Geurts, Frank/0000-0003-2856-9090; Clement, Emyr/0000-0003-3412-4004; Ventura, Sandro/0000-0002-8938-2193; Delgado Peris, Antonio/0000-0002-8511-7958; Janssen, Tahys/0000-0002-3998-4081; Konecki, Marcin/0000-0001-9482-4841; Hamel De Monchenault, Gautier/0000-0002-3872-3592; Ecklund, Karl/0000-0002-6976-4637; Dutta, Valentina/0000-0001-5958-829X; Petrucciani, Giovanni/0000-0003-0889-4726; Landsberg, Greg/0000-0002-4184-9380; Kole, Gouranga/0000-0002-3285-1497; Forthomme, Laurent/0000-0002-3302-336X; Smith, Wesley/0000-0003-3195-0909; Fouz Iglesias, Maria Cruz/0000-0003-2950-976X; Verdier, Patrice/0000-0003-3090-2948; Saka, Halil/0000-0001-7616-2573; Taylor, Lucas/0000-0002-6584-2538; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Lucchini, Marco Toliman/0000-0002-7497-7450; Tytgat, Michael/0000-0002-3990-2074; Galli Mercadante, Pedro/0000-0001-8333-4302; Kasemann, Matthias/0000-0002-0429-2448; Reis, Thomas/0000-0003-3703-6624; Leonardo, Nuno/0000-0002-9746-4594; Sanchez-Hernandez, Alberto/0000-0001-9548-0358; Martinez Ruiz Del Arbol, Pablo/0000-0002-7737-5121; Spagnolo, Paolo/0000-0001-7962-5203; Canelli, Florencia/0000-0001-6361-2117; Dragicevic, Marko/0000-0003-1967-6783; Androsov, Konstantin/0000-0003-2694-6542; Kreczko, Luke/0000-0003-2341-8330; Raidal, Martti/0000-0001-7040-9491; Chatterjee, Suman/0000-0003-2660-0349; Gonzalez Lopez, Oscar/0000-0002-4532-6464; Steggemann, Jan/0000-0003-4420-5510; Alverson, George/0000-0001-6651-1178; Waltenberger, Wolfgang/0000-0002-6215-7228; Rabbertz, Klaus/0000-0001-7040-9846; Escalante Del Valle, Alberto/0000-0002-9702-6359; Melo Da Costa, Eliza/0000-0002-5016-6434; Puerta Pelayo, Jesus/0000-0001-7390-1457; Fernandez Perez Tomei, Thiago Rafael/0000-0002-1809-5226; Botta, Cristina/0000-0002-8072-795X; Tonelli, Guido Emilio/0000-0003-2606-9156; De Guio, Federico/0000-0001-5927-8865; Pieri, Marco/0000-0003-3303-6301; Benitez, J.F./0000-0002-2633-6712; Martelli, Arabella/0000-0003-3530-2255; Rebello Teles, Patricia/0000-0001-9029-8506; Bethani, Agni/0000-0002-8150-7043; Cepeda, Maria/0000-0002-6076-4083; Hahn, Kristian/0000-0001-7892-1676; Novaes, Sergio/0000-0003-0471-8549; Rinkevicius, Aurelijus/0000-0002-7510-255X; Sharma, Varun/0000-0003-1287-1471; Grandi, Claudio/0000-0001-5998-3070; Kogler, Roman/0000-0002-5336-4399; Vischia, Pietro/0000-0002-7088-8557; Mitselmakher, Guenakh/0000-0001-5745-3658; Meola, Sabino/0000-0002-8233-7277; Titov, Maxim/0000-0002-1119-6614; Walsh, Roberval/0000-0002-3872-4114; Hinzmann, Andreas/0000-0002-2633-4696; Mundim, Luiz/0000-0001-9964-7805; Wallny, Rainer/0000-0001-8038-1613; Malgeri, Luca/0000-0002-0113-7389; Abbiendi, Giovanni/0000-0003-4499-7562; Haller, Johannes/0000-0001-9347-7657; Delaere, Christophe/0000-0001-8707-6021; Tao, Junquan/0000-0003-2006-3490; Beaudette, Florian/0000-0002-1194-8556; Herndon, Matthew/0000-0003-3043-1090; Kyberd, Paul/0000-0002-7353-7090; Redondo, Ignacio/0000-0003-3737-4121; /0000-0002-1153-816X; Rolandi, Luigi (Gigi)/0000-0002-0635-274X; Brooke, James/0000-0003-2529-0684; Goy Lopez, Silvia/0000-0001-6508-5090; Kolberg, Ted/0000-0002-0211-6109; Costa, Salvatore/0000-0001-9919-0569; Gerosa, Raffaele/0000-0001-8359-3734; Levchuk, Leonid/0000-0001-5889-7410; Tinoco Mendes, Andre David/0000-0001-5854-7699; Blekman, Freya/0000-0002-7366-7098; Chahal, Gurpreet Singh/0000-0003-0320-4407; Duarte, Javier Mauricio/0000-0002-5076-7096; Wang, Dayong/0000-0002-9013-1199; Moon, Chang-Seong/0000-0001-8229-7829; Manzoni, Riccardo Andrea/0000-0002-7584-5038; Collard, Caroline/0000-0002-5230-8387; Li, Qiang/0000-0002-8290-0517; Belyaev, Andrey/0000-0003-1692-1173; Benaglia, Andrea Davide/0000-0003-1124-8450; Schroder, Matthias/0000-0001-8058-9828; Dewanjee, Ram Krishna/0000-0001-6645-6244; Lipton, Ronald/0000-0002-6665-7289; Heredia De La Cruz, Ivan/0000-0002-8133-6467; Bloom, Kenneth/0000-0002-4272-8900; Vilela Pereira, Antonio/0000-0003-3177-4626; Singh, Jasbir/0000-0001-9029-2462; Feld, Lutz/0000-0001-9813-8646; Kim, Tae Jeong/0000-0001-8336-2434; Alcaraz Maestre, Juan/0000-0003-0914-7474; Heath, Helen/0000-0001-6576-9740; Alves, Gilvan/0000-0002-8369-1446; Bortignon, Pierluigi/0000-0002-5360-1454; Bernardes, Cesar Augusto/0000-0001-5790-9563; Ligabue, Franco/0000-0002-1549-7107; Golf, Frank/0000-0003-3567-9351; Litov, Leandar/0000-0002-8511-6883; Pastrone, Nadia/0000-0001-7291-1979; Padula, Sandra S./0000-0003-3071-0559; Yagil, Avi/0000-0002-6108-4004; Attia Mahmoud, Mohammed/0000-0001-8692-5458; Rappoccio, Salvatore/0000-0002-5449-2560; Belyaev, Alexander/0000-0002-1733-4408; Everaerts, Pieter/0000-0003-3848-324X; Jabeen, Shabnam/0000-0002-0155-7383; Gonzalez Caballero, Isidro/0000-0002-8087-3199; Noll, Dennis Daniel Nick/0000-0002-0176-2360; Fernandez Menendez, Javier/0000-0002-5213-3708; Goldstein, Joel/0000-0003-1591-6014; Sznajder, Andre/0000-0001-6998-1108; Fernandez Bedoya, Cristina/0000-0001-8057-9152; Naimuddin, Md/0000-0003-4542-386X; Josa Mutuberria, Isabel/0000-0002-4985-6964; Missiroli, Marino/0000-0002-1780-1344; Evdokimov, Olga/0000-0002-1250-8931; Dubinin, Mikhail/0000-0002-7766-7175; Wardle, Nicholas/0000-0003-1344-3356; Marzocchi, Badder/0000-0001-6687-6214; Dasu, Sridhara/0000-0001-5993-9045; Brigljevic, Vuko/0000-0001-5847-0062; Gershtein, Yuri/0000-0002-4871-5449; Malik, Sudhir/0000-0002-6356-2655; Jafari, Abideh/0000-0001-7327-1870; Verdini, Piero Giorgio/0000-0002-0042-9507; Gutsche, Oliver/0000-0002-8015-9622; Lethuillier, Morgan/0000-0001-6185-2045; Robert, Schoefbeck/0000-0002-2332-8784; Yazgan, Efe/0000-0001-5732-7950; Gomez-Ceballos, Guillelmo/0000-0003-1683-9460; Azzurri, Paolo/0000-0002-1717-5654; Ulrich, Ralf/0000-0002-2535-402X; Hajahmad (Wael Haj Ahmad), Vael/0000-0003-1491-0446; Rizzi, Andrea/0000-0002-4543-2718A search for heavy neutral leptons (HNLs) decaying in the CMS muon system is presented. A data sample is used corresponding to an integrated luminosity of 138 fb(-1) of proton-proton collisions at root s = 13 TeV, recorded at the CERN LHC in 2016-2018. Decay products of long-lived HNLs could interact with the shielding materials in the CMS muon system and create hadronic and electromagnetic showers detected in the muon chambers. This distinctive signature provides a unique handle to search for HNLs with masses below 4 GeV and proper decay lengths of the order of meters. The signature is sensitive to HNL couplings to all three generations of leptons. Candidate events are required to contain a prompt electron or muon originating from a vertex on the beam axis and a displaced shower in the muon chambers. No significant deviations from the standard model background expectation are observed. In the electron (muon) channel, the most stringent limits to date are set for HNLs in the mass range of 2.1-3.0 (1.9-3.3) GeV, reaching mixing matrix element squared values as low as 8.6(4.6) x 10(-6).eninfo:eu-repo/semantics/openAccessArticleQ1Q11101WOS:0014374334000020