Search for heavy sterile neutrinos in trileptons at the LHCK. W. was Supported by the International Postdoctoral Exchange Fellowship Program (No.90 Document of OCPC, 2015); C. S. K. by the NRF grant funded by the Korean government of the MEST (No. 2016R1D1A1A02936965); and C. D. by Chile grants Fondecyt No. 1130617, Conicyt ACT 1406 and PIA/Basal FB0821

Dib, Claudio O. (CCTVal and Department of Physics, Universidad Técnica Federico Santa María, Valparaíso, Chile) ; Kim, C. S. (Department of Physics and IPAP, Yonsei University, Seoul 120-749, Korea) ; Wang, Kechen (DESY, Notkestrae 85, D-22607 Hamburg, Germany) (Center for Future High Energy Physics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China)

02 November 2017

Abstract: We present a search strategy for both Dirac and Majorana sterile neutrinos from the purely leptonic decays of W± → e± e± μ∓ν and μ± μ± e∓ν at the 14 TeV LHC. The discovery and exclusion limits for sterile neutrinos are shown using both the Cut-and-Count (CC) and Multi-Variate Analysis (MVA) methods. We also discriminate between Dirac and Majorana sterile neutrinos by exploiting a set of kinematic observables which differ between the Dirac and Majorana cases. We find that the MVA method, compared to the more common CC method, can greatly enhance the discovery and discrimination limits. Two benchmark points with sterile neutrino mass mN = 20 GeV and 50 GeV are tested. For an integrated luminosity of 3000 fb−1, sterile neutrinos can be found with 5σ significance if heavy-to-light neutrino mixings |UNe|2 ∼ |UNμ|2∼ 10−6, while Majorana vs. Dirac discrimination can be reached if at least one of the mixings is of order 10−5.

Published in: Chinese Phys. C 41 (2017) 103103
Published by: Institute of Physics Publishing/Chinese Academy of Sciences
DOI: 10.1088/1674-1137/41/10/103103
arXiv: 1703.01936
License: CC-BY-3.0

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