Speaker
Description
Heavy Neutral Leptons (HNLs) are a well-motivated extension of the Standard Model which may provide explanations for observed neutrino masses, dark matter, and baryogengesis via leptogenesis. In the event that a HNL signal is actually detected, much work will be dedicated to identifying the underlying nature of the observed signal excess. In this talk, we will use Monte-Carlo simulations of HNLs generated in FORESEE to explore the potential of the proposed FASER2 experiment at the LHC to determine the properties of a discovered HNL, including its mass, couplings, and whether it is a Majorana or Dirac fermion. We consider the ability of FASER2 to make these measurements from kinematics alone and additionally explore the possibility of using FASER2 as a trigger for ATLAS and measuring the charge of muons produced in association with the HNL at ATLAS to search for lepton number violation. These results show that FASER2, sometimes in coordination with ATLAS, can precisely determine the HNL properties and showcases that main LHC detectors and proposed auxiliary detectors can have a synergistic relationship on an event-by-event basis.