Introducing a novel event generator for electron-nucleus and neutrino-nucleus scattering

Abstract

We present a novel lepton-nucleus event generator: ACHILLES, A CHIcago Land Lepton Event Simulator. The generator factorizes the primary interaction from the propagation of hadrons in the nucleus, which allows for a great deal of modularity, facilitating further improvements and interfaces with existing codes. We validate our generator against high-quality electron-carbon scattering data in the quasielastic regime, including the recent CLAS/e4v reanalysis of existing data. We find promising agreement in both inclusive and exclusive distributions. By varying the assumptions on the propagation of knocked-out nucleons throughout the nucleus, we estimate a component of theoretical uncertainties. We also propose novel observables that will allow for further testing of lepton-nucleus scattering models. ACHILLES is readily extendable to generate neutrino-nucleus scattering events.