Time-Delayed Electrons from Higgs Decays to Right-Handed Neutrinos

We consider the physics reach at the high luminosity LHC (HL-LHC) using the timing capability of a minimum ionizing particle (MIP) timing layer and the electromagnetic calorimeter in the CMS experiment for a simplified right-handed neutrino effective theory. In the simplified model, the lightest right-handed neutrinos are produced through higgs decay with mean decay lengths of order $\mathcal{O}(0.1~{\rm m}-100~{\rm m}$) and then subsequently decay into final states that include electrons. We consider the effect of several different kinematic cuts for a timing based analysis of this model. We demonstrate that if timing information can be successfully incorporated into the event trigger, it is possible to probe the higgs branching ratio to two right-handed neutrinos to the order $\mathcal{O}(10^{-5})$ for a range of different right-handed neutrino lifetimes.