Artur Ankowski

Path to accurate neutrino cross sections

To shed light on the difference between matter and antimatter in the Universe, the Deep Underground Neutrino Experiment (DUNE) and Hyper-Kamiokande will analyze the oscillations of neutrinos and antineutrinos with unprecedented precision. The success of these challenging studies requires a substantial improvement of our understanding of neutrino interactions with atomic nuclei over the next decade. Dedicated studies performed in the MINERvA experiment show that the simulations currently available are woefully inadequate to meet the needs of the oscillation program. This issue can lead to a sizable bias in the extracted oscillation parameters. In this talk, I will present DUNE and Hyper-K in the broad context of rapidly progressing neutrino physics, and explain why it is difficult to pinpoint the origin of the discrepancy between the model and data based on neutrino data alone. I will argue that electron-nucleus and neutrino-nucleus interactions share a lot of common physics, but electron scattering offers a fundamental advantage of precisely known kinematics of interaction, in addition to much higher cross sections. Discussing a recent article [PRD 102, 053001 (2020), arxiv:2006.11944], I will present the most extensive comparison to date of the cross sections from GENIE, the Monte Carlo generator most commonly used in neutrino physics, against electron-scattering data, exploring the kinematics of DUNE and Hyper-K. I will discuss a number of problems that need to be resolved, show to what extent other generators employed in neutrino physics also suffer from these issues, and offer directions for possible improvements.