Understanding the energy resolution of liquid argon neutrino detectors

Abstract

Available estimates for the energy resolution of DUNE vary by as much as a factor of four. To address this controversy, and to connect the resolution to the underlying physical processes, we build an independent simulation pipeline for neutrino events in liquid argon, combining the public tools GENIE and FLUKA. Using this pipeline, we first characterize the channels of non-hermeticity of DUNE, including subthreshold particles, charge recombination, and nuclear breakup. Particular attention is paid to the role of neutrons, which are responsible for a large fraction of missing energy in all channels. Next, we determine energy resolution, by quantifying event-to-event stochastic fluctuations in missing energy. This is done for several sets of assumptions about the reconstruction performance, including those available in the literature. The resulting migration matrices, connecting true and reconstructed neutrino energies, are presented. Finally, we quantify the impact of different improvements on the experimental performance. For example, we show that dropping particle identification information degrades the resolution by a factor of two, while omitting charge deposits from de-excitation gammas worsens it by about 25%. In the future, this framework can be used to assess the impact of cross section uncertainties on the oscillation sensitivity.

Neutrino topology reconstruction at DUNE and applications to searches for dark matter annihilation in the Sun

“…We also note that a recent paper [61] has suggested that dramatic improvements in DUNE's expected energy resolution, relative to the results of [25], can be made by utilizing information about quenching, as well as more optimistic estimates of the DUNE particle identification thresholds. We emphasize that these techniques are entirely complementary to the ones we have described here.…”

Lepton-nucleus cross section measurements for DUNE with the LDMX detector

“…This is not a small effect, and existing differences among generator models consistent with available validation data can yield energy reconstruction variations as large as 20%, which has been discussed systematically in Ref. [38], together with other factors impacting the energy resolution.…”

Physics with beam tau-neutrino appearance at DUNE

“…Here, we assumed the following values for the oscillation parameters [10], in agreement with the most recent global-fit results obtained by the NuFit collaboration [17]: sin 2 θ 12 = 0.310, sin 2 θ 13 = 0.02240, sin 2 θ 23 = 0.582, δ CP = 217 • = −2.50 rad, † Albeit not at all trivial and still under intense investigation, see, for example, Refs. [12,13]. Unless otherwise stated, we will assume these oscillation parameters to be the true values in our analyses going forward.…”