PRECISE MEASUREMENT OP sin~2 2θ_(13) USING JAPANESE REACTORS

摘要

After the Kam LAND results, the remaining important targets in neutrino experiments are to measure still unknown 3 basic parameters; absolute neutrino mass scale, CP violation phase δ_(cp) and last mixing angle δ_(13). The angle θ_(13) among them is expected to be measured in near future by long baseline accelerator experiments and reactor experiments. In this paper, a realistic idea of high sensitivity reactor measurement of sin~2 2θ_(13) is described. This experiment uses a giant nuclear power plant as the neutrino source and three identical detectors are used to cancel detector and neutrino flux uncertainties. The sensitivity reach on sin~2 2θ_(13) is 0.017 ～ 0.026 at Δm_(13)~2 ～ 3 * 10~(-3)eV~2, which is five to seven times better than the current upper limit measured by CHOOZ.