The race is on to pinpoint θ13, the last unknown mixing angle and a key parameter needed to decode neutrino oscillation. The Double Chooz experiment being constructed in northern France is poised to get results first, while a rival experiment at southern China’s Daya Bay will aim for greater sensitivity.
Following a long tradition—from the first detection of neutrinos in the 1950s at Savannah River in South Carolina to the ongoing KamLAND experiment in Japan—both the Double Chooz and Daya Bay experiments will monitor antineutrinos emitted from nuclear power reactors. They will watch for the disappearance of electron antineutrinos by comparing the flux and energy spectrum in detectors located far from and close to the reactors. “An effect could be seen independently by these two means,” says Double Chooz spokesman Hervé de Kerret of the Astroparticle and Cosmology Laboratory at the University of Paris VII. “If both of...