Upper limits on perturbations of nuclear decay rates induced by reactor electron antineutrinos.

We report the results of an experiment conducted near the High Flux Isotope Reactor of Oak Ridge National Laboratory, designed to address the question of whether a flux of reactor-generated electron antineutrinos (ν¯) can alter the rates of weak nuclear interaction induced decays of Mn, Na, and Co. This experiment has small statistical errors but, when systematic uncertainties are included, has null results. Perturbations greater than one part in 10 are excluded at 95% confidence level in β decay and electron capture processes, in the presence of an antineutrino flux of 3 × 10 cms. The present experimental methods are applicable to a wide range of radionuclides. Improved sensitivity in future experiments can be anticipated as we continue to better understand and reduce the dominant systematic uncertainties.