Neutrino-electron elastic scattering for flux determination at the DUNE oscillation experiment

Abstract

We study the feasibility of using neutrino-electron elastic scattering to measure the neutrino flux in the DUNE neutrino oscillation experiment. The neutrino-electron scattering cross section is precisely known, and the kinematics of the reaction allow determination of the incoming neutrino energy by precise measurement of the energy and angle of the recoiling electron. For several possible near detectors, we perform an analysis of their ability to measure neutrino flux in the presence of backgrounds and uncertainties. With realistic assumptions about detector masses, we find that a liquid argon detector, even with limitations due to angular resolution, is able to perform better than less dense detectors with more precise event-by-event neutrino energy measurements. We find that the absolute flux normalization uncertainty can be reduced from ∼8% to ∼2%, and the uncertainty on the flux shape can be reduced by ∼20-30%.

Long-baseline neutrino oscillation physics potential of the DUNE experiment

“…In addition to the samples used explicitly in this analysis, the LArTPC is expected to measure numerous exclusive finalstate CC channels, as well as ν e and NC events. Additionally, neutrino-electron elastic scattering [64] and the low-ν technique [65][66][67][68][69][70] may be used to constrain the flux. Additional samples of events from other detectors in the DUNE ND complex are not explicitly included here, but there is an assumption that we will be able to control the uncertainties to the level used in the analysis, and it should be understood that that implicitly relies on having a highly capable ND.…”

“…We note that there are many possible ND samples which are not included in the current analysis, but which may either help improve the sensitivity in future, or will help control uncertainties to the level assumed here. These include: neutrino-electron scattering studies, which can independently constrain the flux normalization to ∼2% [64]; additional flux constraints from the low-ν method, which exploits the fact that the low energy transfer (low-ν) cross section is roughly constant with neutrino energy [65][66][67][68][69][70]; and using interactions on the gaseous argon (GAr) in the MPD. There is also the potential to include events where the muon does not pass through the MPD, e.g.…”

Design and Diagnostics of High-Precision Accelerator Neutrino Beams

“…As mentioned in Section10.3, the ND cannot measure the flux in a direct manner because it cannot disentangle the product φ(E) (E)σ(E) neither for ν e nor for ν µ . A possible way out that can be implemented in high-intensity wide-band beam is the use of the neutrino elastic scattering on the electrons of the detector medium [157,158]:…”

Measuring the Weak Mixing Angle in the DUNE near-Detector Complex

“…Second, while the neutrino-electron cross section depends mostly on sin 2 θ W , the neutrino beam originates from the in-flight decay of charged mesons produced by high-energy protons hitting a fixed target. First-principles computations of the meson production rate and kinematics are not possible and one must rely on phenomenological models and experimental data; uncertainties on the overall neutrino flux and energy distribution are at the 5% to 15% level [33][34][35].…”

“…Near-detector complexes are designed to circumvent some of the large uncertainties in the flux and cross sections and allow precision measurements of neutrino oscillations [35]. DUNE-PRISM [36], currently part of the LBNF-DUNE proposal, is a near detector that is capable of moving in the direction perpendicular to the neutrino-beam axis.…”