Long-lived heavy neutral leptons at the LHC: four-fermion single-$N_R$ operators
Abstract
Interest in searches for heavy neutral leptons (HNLs) at the LHC has increased considerably in the past few years. In the minimal scenario, HNLs are produced and decay via their mixing with active neutrinos in the Standard Model (SM) spectrum. However, many SM extensions with HNLs have been discussed in the literature, which sometimes change expectations for LHC sensitivities drastically. In the SMEFT, one extends the SM effective field theory with operators including SM singlet fermions, which allows to study HNL phenomenology in a "model independent" way. In this paper, we study the sensitivity of ATLAS to HNLs in the SMEFT for four-fermion operators with a single HNL. These operators might dominate both production and decay of HNLs, and we find that new physics scales in excess of 20 TeV could be probed at the high-luminosity LHC.
Keywords
Cite
@article{arxiv.2110.15096,
title = {Long-lived heavy neutral leptons at the LHC: four-fermion single-$N_R$ operators},
author = {Rebeca Beltrán and Giovanna Cottin and Juan Carlos Helo and Martin Hirsch and Arsenii Titov and Zeren Simon Wang},
journal= {arXiv preprint arXiv:2110.15096},
year = {2022}
}
Comments
18 pages, 3 figures, 2 tables; Fig. 1 updated with the latest CMS constraints; several comments and references added; results unchanged; matches version published in JHEP