Heavy Neutrinos at Large Colliders

In this work we discuss the state of the art of the heavy neutrinos at colliders. The neutrinos in the Standard Model (SM) are considered to be massless which is in contradiction with the evidence from the neutrino oscillations experiments. These cosmological observations established that at least two SM neutrinos have non-zero masses and that individual lepton number is violated. Therefore a strong conclusive first evidence of new physics caused by the neutrino mass mechanism is emerged. In this work we discuss the collider phenomenology of neutrino mass models at the existing (LHC) and next generation large colliders (FCC: ee, hh, eh, ILC and CePC) at different high synergies. It is naturally known that colliders are not sensitive to the SM light neutrinos; however the production of heavy neutrinos is very possible to be detected; giving rise to several signal processes which are categorised by different final state topologies according to theirs physics interests. We will present the state of the art of the heavy neutrinos generated with radiative neutrino mass models and their experimental searches; mainly for Majorana neutrino signals allowing for probing the nature of the Dark Matter candidates at high energy colliders. The focus will be on the well-motivated neutrino mass models which provide an elegant framework to explore new directions in Dark Matter phenomenology at the TeV scale and the future experimental prospects.