Reactor antineutrino anomaly

Recently, new reactor antineutrino spectra have been provided for U-235, Pu-239, Pu-241, and U-238, increasing the mean flux by about 3%. To a good approximation, this reevaluation applies to all reactor neutrino experiments. The synthesis of published experiments at reactor-detector distances <100 m leads to a ratio of observed event rate to predicted rate of 0.976 +/- 0.024. With our new flux evaluation, this ratio shifts to 0.943 +/- 0.023, leading to a deviation from unity at 98.6% C. L. which we call the reactor antineutrino anomaly. The compatibility of our results with the existence of a fourth nonstandard neutrino state driving neutrino oscillations at short distances is discussed. The combined analysis of reactor data, gallium solar neutrino calibration experiments, and MiniBooNE-nu data disfavors the no-oscillation hypothesis at 99.8% C. L. The oscillation parameters are such that vertical bar Delta m(new)(2)vertical bar > 1.5 eV(2) (95%) and sin(2) (2 theta(new)) = 0.14 +/- 0.08 (95%). Constraints on the theta(13) neutrino mixing angle are revised.