Search for Heavy Majorana Neutrinos in Same-Sign Dilepton Channels in Proton-Proton Collisions at √s = 13 TeV
Author(s)CMS Collaboration; Abercrombie, Daniel Robert; Allen, Brandon Leigh; Azzolini, Virginia; Baty, Austin Alan; Bauer, Gerry P; Bi, Ran; Brandt, Stephanie Akemi; Busza, Wit; Cali, Ivan Amos; D'Alfonso, Mariarosaria; Demiragli, Zeynep; Gomez-Ceballos, Guillelmo; Goncharov, Maxim; Harris, Philip Coleman; Hsu, Dylan George; Hu, Miao; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Lee, Yen-Jie; Luckey Jr, P David; Maier, Benedikt; Marini, Andrea Carlo; McGinn, Christopher Francis; Mironov, Camelia Maria; Narayanan, Siddharth Madhavan; Niu, Xinmei; Paus, Christoph M. E.; Roland, Christof E; Roland, Gunther M; Stephans, George S. F.; Sumorok, Konstanty C; Tatar, Kaya; Velicanu, Dragos Alexandru; Wang, Jing; Wang, Ta-Wei; Wyslouch, Boleslaw; Shi, Zhaozhong; ... Show more Show less
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A search is performed for a heavy Majorana neutrino (N), produced in leptonic decay of a W boson propagator and decaying into a W boson and a lepton, with the CMS detector at the LHC. The signature used in this search consists of two same-sign leptons, in any flavor combination of electrons and muons, and at least one jet. The data were collected during 2016 in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb⁻¹. The results are found to be consistent with the expected standard model background. Upper limits are set in the mass range between 20 and 1600 GeV in the context of a Type-I seesaw mechanism, on |VeN|², |VμN|², and |VeNV μN * |²/(|VeN|² + |VμN|²), where VℓN is the matrix element describing the mixing of N with the standard model neutrino of flavor ℓ = e, μ. For N masses between 20 and 1600 GeV, the upper limits on |VℓN|2 range between 2.3 × 10⁻⁵ and unity. These are the most restrictive direct limits for heavy Majorana neutrino masses above 430 GeV.
DepartmentMassachusetts Institute of Technology. Department of Nuclear Science and Engineering; Massachusetts Institute of Technology. Department of Physics; Massachusetts Institute of Technology. Laboratory for Nuclear Science
Journal of High Energy Physics
Sirunyan, A. M. et al. “Search for Heavy Majorana Neutrinos in Same-Sign Dilepton Channels in Proton-Proton Collisions at √s = 13 TeV.” Journal of High Energy Physics 2019, 1 (January 2019): 122 © 2019 The Author(s)
Final published version