Speaker
Description
Long-lived particles (LLPs) could serve as a portal to hidden sectors addressing different open problems of the Standard Model. Among these, the evidence for neutrino masses and mixings—observed in neutrino oscillation experiments—stands out as particularly promising. A simple extension to the SM involves the inclusion of heavy right-handed neutrinos, commonly known as heavy neutral leptons (HNLs). In minimal models, the HNL production and decay are governed by weak interactions, suppressed by their mixing with active neutrinos. This suppression leads to relatively long HNL lifetimes when their masses lie within the MeV–GeV range.
The near-detector complexes of current and upcoming neutrino oscillation experiments provide an optimal environment for searching for visible HNL decays, given the high intensity of the beams and the volume of the detectors involved. We have conducted a comprehensive study on both the physics case and the technical feasibility of a dedicated HNL search utilizing the 120-GeV proton NuMI beam with an ICARUS-like detector. Our analysis indicates that the projected constraints on HNL mixing as a function of its mass will be highly competitive with existing experimental limits.
