Neutrino-deuteron scattering: Uncertainty quantification and new L1,A constraints

We study neutral- and charged-current (anti)neutrino-induced dissociation of the deuteron at energies from threshold up to 150 MeV by employing potentials, as well as one- and two-body currents, derived in chiral effective field theory (χEFT). We provide uncertainty estimates from χEFT truncations of the electroweak current, dependences on the χEFT cutoff, and variations in the pool of fit data used to fix the low-energy constants of χEFT. At 100 MeV of incident (anti)neutrino energy, these uncertainties amount to about 2-3% and are smaller than the sensitivity of the cross sections to the single-nucleon axial form factor, which amounts to 5% if one varies the range of the nucleon axial radius within the bands determined by recent lattice quantum chromodynamics evaluations and phenomenological extractions. We conclude that a precise determination of the nucleon axial form factor is required for a high-precision calculation of the neutrino-deuteron cross sections at energies higher than 100 MeV. By matching our low-energy χEFT results to those of pionless effective field theory (πEFT), we provide new constraints for the counterterm L1,A that parametrizes the strength of the axial two-body current in πEFT. We obtain a value of 4.9-1.5+1.9fm3 at renormalization scale set to pion mass, which is compatible with, albeit narrower than, previous experimental determinations, and comparable to a recent lattice quantum chromodynamics calculation.