Sensitivities of low energy reactor neutrino experiments

The low energy part of the reactor neutrino spectra has not been measured experimentally. Its uncertainties limit the sensitivities in certain reactor neutrino experiments. This paper discusses the origin of these uncertainties and examines their effects on the measurements of neutrino interactions with electrons and nuclei. The discrepancies between previous results and the standard model expectations can be explained by the underestimation of the reactor neutrino spectra at low energies. To optimize the experimental sensitivities, measurements for e–e cross-sections should focus on events with large (>1.5 MeV) recoil energy while those for neutrino magnetic moment searches should focus on events <100 keV. The merits and attainable accuracies for neutrino–electron scattering experiments using artificial neutrino sources are discussed.