We study the phenomenology of heavy neutral leptons (HNLs) at the LHC in effective field theory, concentrating on d=6 operators with top quarks. Depending on the operator choice and HNL mass, the HNLs will be produced either from proton-proton collisions in association with a single top, or via non-standard decays of top quarks. For long-lived HNLs we estimate the sensitivity reach of different detectors to various operators with top quarks and the HNLs for the high-luminosity phase of the LHC. For certain operators, ATLAS and some far detectors (MATHUSLA and ANUBIS) will be able to probe the associated new-physics scale as large as 12 TeV and 4.5 TeV, respectively, covering complementary HNL-mass ranges.
@article{arxiv.2501.09065,
title = {Heavy neutral leptons and top quarks in effective field theory},
author = {Rebeca Beltrán and Giovanna Cottin and Julian Günther and Martin Hirsch and Arsenii Titov and Zeren Simon Wang},
journal= {arXiv preprint arXiv:2501.09065},
year = {2025}
}
Comments
ATLAS sensitivity in figures 6, 7 and 8 updated. Conclusions unchanged