Improved Measurement of Antineutrino Disappearance at Daya Bay

The Daya Bay Experiment observed the disappearance of a statistically significant number of antineutrinos from the reactors at Daya Bay. Based on 139 days of data taken with 6 antineutrino detectors, we measured about 6% deficit of antineutrinos at the far site, located at about 2 km from the reactors, corresponding to a value of .