Generating Heavy Neutral Lepton events via FeynRules and MadGraph5

The model for the event generation was taken from arxiv.org/pdf/1806.07396.pdf. It is a type-I seesaw mechanism, in which the existence of heavy sterile right-handed neutrinos is assumed. Those neutrinos have an 𝐻𝜈𝑁 interaction vertex, which leads to the mass mixing due to nonzero Higgs vacuum expectation value.