Speaker
Description
Neutrino physics has entered an era of precision measurement, and liquid argon time projection chambers (LArTPCs) are a popular detector choice due to their high spatial and energy resolution. One of the most poorly-characterized sources of neutrino cross-section uncertainties in LArTPCs, specifically for pionless final states, is pion production and reabsorption in the nucleus. Constraining this source of uncertainty is essential for improving the precision of measurements in next-generation LArTPCs like the Deep Underground Neutrino Experiment (DUNE). We present the first direct measurement of the absorption cross section of negative pions on argon. Using the Liquid Argon In A Testbeam (LArIAT) Experiment, we measure the cross section for negative pions incident with 100-600 MeV of kinetic energy, separately for events with 0 and >0 visible protons. This result complements prior measurements from LADS and ProtoDUNE that measured positive pions in other energy ranges. We use this measurement to assess the accuracy of multiple model predictions, including GENIE hA/hN, INCL++, and Geant4.