Journal Article

Search for heavy neutral leptons in decays of W bosons produced in 13 TeV pp collisions using prompt and displaced signatures with the ATLAS detector

Alexandre, D., Bernard, N. R., Walkowiak, W., Peiffer, T., Raine, J. A., Cuhadar Donszelmann, T., Lucotte, A., Introzzi, G., Zanzi, D., Henkelmann, S., Gao, Y., Strom, D. M., Meyer, J-P., Ezhilov, A., Fabbri, L., Falke, P. J., Emerman, A., Aguilar-Saavedra, J. A., Carminati, L., Cantero, J., Hubaut, F., Hsu, S.-C., Pedro, R., Gregersen, K., Meyer, C., Hageböck, S., Luise, I., Mellado Garcia, B. R., Diaz, M. A., Dudarev, A., Atmani, H., Oren, Y., Borissov, G., Bruni, L. S., Kajomovitz, E., Yang, Y., Beddall, A., La Ruffa, F., Catmore, J. R., Asimakopoulou, E. M., Calafiura, P., Gonzalez-Sevilla, S., Korn, A., Pogrebnyak, I., Laplace, S., AbouZeid, O. S., Hessey, N. P., Schaefer, D., Trofymov, A., Zhukov, K., Golubkov, D., Krüger, H., Kupfer, T., Butti, P., Heidorn, W. D., Hamdaoui, H., Gazis, E. N., Batley, J. R., Vokac, P., Hawkings, R. J., Yang, X., Kim, Y. K., Levin, D., Ronzani, M., Tu, Y., Schwarz, T. A., Lehmann, K., Calace, N., Rosin, G., Zoccoli, A., Jia, J., Viehhauser, G. H. A., Pettee, M., Cameron, D., Ambroz, L., Looper, K. A., Veloso, F., Zhang, R., Nibigira, E., Fischer, F., Boerner, D., Dervan, P., Tashiro, T., Davidek, T., Debenedetti,

2019

Overview

A bstract The problems of neutrino masses, matter-antimatter asymmetry, and dark matter could be successfully addressed by postulating right-handed neutrinos with Majorana masses below the electroweak scale. In this work, leptonic decays of W bosons extracted from 32.9 fb − 1 to 36.1 fb − 1 of 13 TeV proton–proton collisions at the LHC are used to search for heavy neutral leptons (HNLs) that are produced through mixing with muon or electron neutrinos. The search is conducted using the ATLAS detector in both prompt and displaced leptonic decay signatures. The prompt signature requires three leptons produced at the interaction point (either μμe or eeμ ) with a veto on same-flavour opposite-charge topologies. The displaced signature comprises a prompt muon from the W boson decay and the requirement of a dilepton vertex (either μμ or μe ) displaced in the transverse plane by 4–300 mm from the interaction point. The search sets constraints on the HNL mixing to muon and electron neutrinos for HNL masses in the range 4.5–50 GeV.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V,Springer Berlin
• Subject: Antimatter / Bosons / Classical and Quantum Gravitation / Dark matter / Decay / Displacement / Elementary Particles / Flavor (particle physics) / Fysik / Hadron-Hadron scattering (experiments) / High energy physics / Large Hadron Collider / Leptons / Muons / Natural Sciences / Naturvetenskap / Neutrinos / Particle collisions / Physical Sciences / Physics / Physics and Astronomy / Protons / Quantum Field Theories / Quantum Field Theory / Quantum Physics / Regular Article - Experimental Physics / Relativity Theory / Searching / Signatures / String Theory / Subatomic Physics / Subatomär fysik / Topology