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

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.

Automated summary

We introduce a new lepton-nucleus event generator called ACHILLES, which separates the primary interaction from hadron propagation in the nucleus, allowing for modularity and interface with existing codes. The generator is validated against high-quality electron-carbon scattering data and shows promising agreement in both inclusive and exclusive distributions. The generator also proposes novel observables for further testing of lepton-nucleus scattering models. ACHILLES can be extended to generate neutrino-nucleus scattering events.