Search for long-lived heavy neutral leptons with lepton flavour conserving or violating decays to a jet and a charged lepton
Articolo
Data di Pubblicazione:
2024
Abstract:
A search for long-lived heavy neutral leptons (HNLs) is presented, which considers the hadronic final state and coupling scenarios involving all three lepton generations in the 2–20 GeV HNL mass range for the first time. Events comprising two leptons (electrons or muons) and jets are analyzed in a data sample of proton-proton collisions, recorded with the CMS experiment at the CERN LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1. A novel jet tagger, based on a deep neural network, has been developed to identify jets from an HNL decay using various features of the jet and its constituent particles. The network output can be used as a powerful discriminating tool to probe a broad range of HNL lifetimes and masses. Contributions from background processes are determined from data. No excess of events in data over the expected background is observed. Upper limits on the HNL production cross section are derived as functions of the HNL mass and the three coupling strengths VℓN to each lepton generation ℓ and presented as exclusion limits in the coupling-mass plane, as lower limits on the HNL lifetime, and on the HNL mass. In this search, the most stringent limit on the coupling strength is obtained for pure muon coupling scenarios; values of |VμN2| > 5 (4) × 10−7 are excluded for Dirac (Majorana) HNLs with a mass of 10 GeV at a confidence level of 95% that correspond to proper decay lengths of 17 (10) mm.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
Beyond Standard Model; Hadron-Hadron Scattering; Lifetime
Elenco autori:
null, null; Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Hussain, P. S.; Jeitler, M.; Krammer, N.; Li, A.; Liko, D.; Mikulec, I.; Schieck, J.; Schöfbeck, R.; Schwarz, D.; Sonawane, M.; Templ, S.; Waltenberger, W.; Wulz, C.-E.; Darwish, M. R.; Janssen, T.; Van Mechelen, P.; Bols, E. S.; D'Hondt, J.; Dansana, S.; De Moor, A.; Delcourt, M.; El Faham, H.; Lowette, S.; Makarenko, I.; Müller, D.; Sahasransu, A. R.; Tavernier, S.; Tytgat, M.; Van Onsem, G. P.; Van Putte, S.; Vannerom, D.; Clerbaux, B.; Das, A. K.; De Lentdecker, G.; Favart, L.; Gianneios, P.; Hohov, D.; Jaramillo, J.; Khalilzadeh, A.; Lee, K.; Mahdavikhorrami, M.; Malara, A.; Paredes, S.; Pétré, L.; Postiau, N.; Thomas, L.; Vanden Bemden, M.; Vander Velde, C.; Vanlaer, P.; De Coen, M.; Dobur, D.; Hong, Y.; Knolle, J.; Lambrecht, L.; Mestdach, G.; Mota Amarilo, K.; Rendón, C.; Samalan, A.; Skovpen, K.; Van Den Bossche, N.; van der Linden, J.; Wezenbeek, L.; Benecke, A.; Bethani, A.; Bruno, G.; Caputo, C.; Delaere, C.; Donertas, I. S.; Giammanco, A.; Jaffel, K.; Jain, Sa.; Lemaitre, V.; Lidrych, J.; Mastrapasqua, P.; Mondal, K.; Tran, T. T.; Wertz, S.; Alves, G. A.; Coelho, E.; Hensel, C.; Menezes De Oliveira, T.; Moraes, A.; Rebello Teles, P.; Soeiro, M.; Aldá Júnior, W. L.; Alves Gallo Pereira, M.; Barroso Ferreira Filho, M.; Brandao Malbouisson, H.; Carvalho, W.; Chinellato, J.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; Fonseca De Souza, S.; Gomes De Souza, R.; Martins, J.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Pinheiro, J. P.; Santoro, A.; Sznajder, A.; Thiel, M.; Vilela Pereira, A.; Bernardes, C. A.; Calligaris, L.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Orzari, B.; Padula, Sandra S.; Aleksandrov, A.; Antchev, G.; Hadjiiska, R.; Iaydjiev, P.; Misheva, M.; Shopova, M.; Sultanov, G.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Petrov, A.; Shumka, E.; Keshri, S.; Thakur, S.; Cheng, T.; Javaid, T.; Yuan, L.; Hu, Z.; Liu, J.; Yi, K.; Chen, G. M.; Chen, H. S.; Chen, M.; Iemmi, F.; Jiang, C. H.; Kapoor, A.; Liao, H.; Liu, Z.-A.; Sharma, R.; Song, J. N.; Tao, J.; Wang, C.; Wang, J.; Wang, Z.; Zhang, H.; Agapitos, A.; Ban, Y.; Levin, A.; Li, C.; Li, Q.; Mao, Y.; Qian, S. J.; Sun, X.; Wang, D.; Yang, H.; Zhang, L.; Zhou, C.; You, Z.; Lu, N.; Bauer, G.; Gao, X.; Leggat, D.; Okawa, H.; Lin, Z.; Lu, C.; Xiao, M.; Avila, C.; Barbosa Trujillo, D. A.; Cabrera, A.; Florez, C.; Fraga, J.; Reyes Vega, J. A.; Mejia Guisao, J.; Ramirez, F.; Rodriguez, M.; Ruiz Alvarez, J. D.; Giljanovic, D.; Godinovic, N.; Lelas, D.; Sculac, A.; Kovac, M.; Sculac, T.; Bargassa, P.; Brigljevic, V.; Chitroda, B. K.; Ferencek, D.; Mishra, S.; Starodumov, A.; Susa, T.; Attikis, A.; Christoforou, K.; Konstantinou, S.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Saka, H.; Stepennov, A.; Finger, M.; Finger, M.; Kveton, A.; Ayala, E.; Carrera Jarrin, E.; Abdalla, H.; Assran, Y.; Mahmoud, M. A.; Mohammed, Y.; Ehataht, K.; Kadastik, M.; Lange, T.; Nandan, S.; Nielsen, C.; Pata, J.; Raidal, M.; Tani, L.; Veelken, C.; Kirschenmann, H.; Osterberg, K.; Voutilainen, M.; Bharthuar, S.; Brücken, E.; Garcia, F.; Kallonen, K. T. S.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Martikainen, L.; Myllymäki, M.; Rantanen, M. m.; Siikonen, H.; Tuominen, E.; Tuominiemi, J.; Luukka, P.; Petrow, H.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Faure, J. L.; Ferri, F.; Ganjour, S.; Gras, P.; Hamel de Monchenault, G.; Lohezic, V.; Malcles, J.; Rander, J.; Rosowsky, A.; Sahin, M. Ö.; Savoy-Navarro, A.; Simkina, P.; Titov, M.; Tornago, M.; Baldenegro Barrera, C.; Beaudette, F.; Buchot Perraguin, A.; Busson, P.; Cappati, A.; Charlot, C.; Chiusi, M.; Damas, F.; Davignon, O.; De Wit, A.; Fontana Santos Alves, B. A.; Ghosh, S.; Gilbert, A.; Granier de Cassagnac, R.; Hakimi, A.; Harikrishn
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