Using Nucleon Multiplicities to Analyze Anti-Neutrino Interactions with Nuclei

Abstract

The most commonly used, simple interaction models have not accurately described the nuclear effects on either neutrino-nucleus or anti-neutrino-nucleus interactions. Comparison of data collected by the MINERvA experiment and these models shows a discrepancy in the reconstructed hadronic energy distribution at momentum transfers below 0.8 GeV. Two nuclear model effects that were previously not modeled are possible culprits of this discrepancy. The first is known as random-phase-approximation and the second is the addition of a meson exchange current process, also known as two-particle two-hole due to its result in two particles leaving the nucleus with two holes left in their place. For the first time a neutron counting software algorithm has been created and used to compare the multiplicity and spatial distributions of neutrons between the simulation and data. There is localized sensitivity to the RPA and 2p2h effects and both help the simulation better describe the data. Additional systematic or model effects are present which cause the simulation to overproduce neutrons, and potential causes are discussed.