DUNE as the Next-Generation Solar Neutrino Experiment

We show that the Deep Underground Neutrino Experiment (DUNE), with significant but feasible new efforts, has the potential to deliver world-leading results in solar neutrinos. With a 100 kton-yr exposure, DUNE could detect 10⁵ signal events above 5 MeV electron energy. Separate precision measurements of neutrino-mixing parameters and the ⁸B flux could be made using two detection channels (νₑ+⁴⁰Ar and ν_e,μ,τ+e^-) and the day-night effect (>10σ). New particle physics may be revealed through the comparison of solar neutrinos (with matter effects) and reactor neutrinos (without), which is discrepant by ~2σ (and could become 5.6σ). New astrophysics may be revealed through the most precise measurement of the ⁸B flux (to 2.5%) and the first detection of the hep flux (to 11%). DUNE is required: No other experiment, even proposed, has been shown capable of fully realizing these discovery opportunities.