  A reactor-neutrino experiment, Daya Bay, has been proposed to determine the
least-known neutrino mixing angle theta_13 using electron antineutrinos
produced at the Daya Bay nuclear power complex in China. Daya Bay is an
international collaboration with institutions from China, the United States,
the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use
eight identical detectors deployed at three different locations optimized for
monitoring the antineutrino rates from the six reactors and for detecting any
rate deficit and spectral distortion near the first oscillation maximum. The
overburden of the under ground experimental halls, connected with tunnels,
ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic
background is small compared to the number of observed antineutrino events.
Civil construction of tunnels and experimental facilities is planned to start
in 2007, with detector construction beginning in 2008. The experiment will
begin collecting data in 2010. By comparing the detected signals at the three
locations, with three years of data, a sensitivity in sin**2(2theta_13) of
better than 0.01 is expected.
