Year: 2025
Type: article
Abstract: Heavy neutral leptons (HNLs) provide a compelling extension to the Standard Model, addressing the neutrino masses, baryogenesis, and dark matter problems. We perform a model-independent collider study, decoupling the active-sterile mixing angle ( V ) from the Yukawa coupling ( y ), and explore sensitivities at the HL-LHC for prompt and displaced decays. We also consider the possibility of HNLs being long-lived particles decaying in far detectors as FASER. In addition, we study the expected reach at FCC-ee for the prompt and displaced cases. For zero mixing, FCC-ee and HL-LHC sensitivities to y are comparable, with Higgs width measurements imposing the strongest constraints. With nonzero mixing, sensitivities are dominated by V , significantly constraining parameter space. This work highlights the importance of precision Higgs studies and displaced searches in probing HNLs at current and future colliders.
Authors: Nicolás Bernal, Kuldeep Deka, Marta Losada
Institution: New York University Abu Dhabi
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4409922940