Looking for sterile neutrinos in the CMS muon system

The CMS collaboration has recently presented new results in searches for long-lived heavy neutral leptons (HNLs). Also known as “sterile neutrinos”, HNLs are interesting hypothetical particles that could solve three major puzzles in particle physics: they could explain the smallness of neutrino masses via the so-called “see-saw” mechanism, they could explain the matter-antimatter asymmetry of the universe, and at the same time they could provide a candidate for dark matter.