Lu, HQ (reprint author), Chinese Acad Sci, Inst High Energy Phys, Yuquan Rd 19-B, Beijing 100049, Peoples R China.
Neutrinos are elementary particles in the standard model of particle physics. There are three flavors of neutrinos that oscillate among themselves. Their oscillation can be described by a 3x3 unitary matrix, containing three mixing angles theta(12), theta(23), theta(13), and one CP phase. Both theta(12) and theta(23) are known from previous experiments. theta(13) was unknown just two years ago. The Daya Bay experiment gave the first definitive nonzero value in 2012. An improved measurement of the oscillation amplitude sin(2) 2(theta(13)) = 0.090(-0.009)(+0.008) and the first direct measurement of the (nu) over bar (e) mass-squared difference vertical bar Delta m(ee)(2)vertical bar ( 2.59(-0.20)(+0.09)) x 10(-3) eV(2) were obtained recently. The large value of theta(13) boosts the next generation of reactor antineutrino experiments designed to determine the neutrino mass hierarchy, such as JUNO and RENO-50.