Comparing pion production data to Geant4 simulation

The COHERENT collaboration uses the Spallation Neutron Source at the Oak Ridge National Laboratory in Tennessee as a source of free neutrinos. These neutrinos are produced when the 1 GeV pulsed proton beam impinges on a liquid mercury target, producing pions, which eventually lead to substantial neutrino production. In the investigation into coherent elastic neutrino-nucleus scattering the collaboration has previously used a 10% error on the calculations, which comes from comparing an older model implementation to world neutrino flux data. In this work an effort has been made to better quantify how well some reference Geant4 physics lists describe the neutrino production process. Here we present the comparisons of the four models of pion production simulation to old and recent pion-production data on different targets to assess the agreement between models and data.