Event Generation for Neutrino and Muon DIS at the LHC

Abstract

Neutrinos and muons produced in the forward direction of LHC collisions and detected by the FASER and SND@LHC experiments enable a comprehensive deep-inelastic scattering (DIS) programme, covering both neutral and charged currents, at TeV energies. This programme aims to provide stringent constraints on proton and nuclear structure as well as on hadron fragmentation, and to offer novel insight into neutrino interactions at the highest energies achieved in a laboratory. Realising this potential requires accurate and precise simulations of neutral- and charged-current DIS. We systematically compare the predictions of NLO general-purpose Monte Carlo (MC) event generators for neutrino- and muon-initiated DIS at the LHC (Sherpa, Herwig7, and POWHEG) against analytical structure-function calculations (YADISM) and dedicated neutrino simulation packages (GENIE, NuWro, GiBUU). Within this framework, we quantify the role of higher-order QCD corrections, (nuclear) parton distribution functions (PDFs), parton shower and hadronisation modelling, and QED radiation both for inclusive observables and for the FASER fiducial selections. We also present representative applications to the FASER neutrino programme: comparisons with its most recent data from the emulsion and electronic sub-detectors, a study of strange PDF sensitivity in the dimuon final state, and predictions for charged-hadron production in semi-inclusive DIS. Our analysis highlights the agreement of modern event generators for inclusive and differential DIS observables once common settings are adopted, while differences remain for observables sensitive to the hadronic final state.