Argonne National Laboratory

Abstract:
The theory of neutrino oscillations explains changes in neutrino flavor, count rates, and spectra from solar, atmospheric, accelerator, and reactor neutrinos. These oscillations are characterized by three mixing angles and two mass-squared differences. The solar mixing angle, theta_12, and the atmospheric mixing angle, theta_23, have been well measured, but until recently, the neutrino mixing angle theta_13 was not well known.

The Daya Bay experiment, located northeast of Hong Kong at the Guangdong Nuclear Power Complex in China, has made a precise measurement of electron antineutrino disappearance using six functionally-identical Gadolinium-doped liquid scintillator-based detectors at three sites with distances between 364 and 1900 meters from six reactor cores. This talk describes the Daya Bay updated result, using 126 days of data collected between December 24, 2011 and May 11, 2012.