Sterile neutrinos

Neutrinos, being the only fermions in Standard Model of Particle Physics that do not possess electromagnetic or color charges, have unique opportunity to communicate with outside through mass mixing. Such Model-singlet are generally referred as “sterile neutrinos”. In this review article, we discuss theoretical and experimental motivation for sterile neutrinos, well their phenomenological consequences. With benefit hindsight 2020, point out potentially viable interesting ideas. We focus particular on neutrinos light enough participate neutrino oscillations, but also comment benefits introducing heavier states. phenomenology eV-scale terrestrial experiments cosmology, survey global data, highlight various intriguing anomalies. expose severe tension exists between different data sets prevents a consistent interpretation at least simplest models. non-minimal scenarios may alleviate some tension. briefly status keV-scale dark matter possibility explaining matter–antimatter asymmetry Universe leptogenesis driven by yet neutrinos.