Probing right handed neutrinos at the LHeC and lepton colliders using fat jet signatures

The inclusion of heavy neutral leptons (right-handed neutrinos) to the Standard Model (SM) particle content is one of the best motivated ways to account for the observed neutrino masses and flavor mixing. The modification of the charged and neutral currents from active-sterile mixing of the neutral leptons can provide novel signatures which can be tested at the future collider experiments. In this article, we explore the discovery prospect of a very heavy right handed neutrino to probe such extensions at the future collider experiments like Large Hadron electron Collider (LHeC) and liner collider. We consider the production of the heavy neutrino via the $t$ and $s$-channel processes and its subsequent decays into the semi-leptonic final states. We specifically focus on the scenario where the gauge boson produced from heavy neutrino decay is highly boosted, leading to a fat-jet. We study the bounds on the sterile neutrino properties from several past experiments and compare with our results.