Prospects of reactor neutrino experiments

Since the energy of a reactor neutrino is a few MeV, all Δ m 12 2 , Δ m 23 2 and Δ m 13 2 oscillations are accessible by reactor neutrino experiments. KamLAND observed the Δ m 12 2 oscillation and currently Double Chooz, RENO and Dayabay experiments are under construction aiming to detect Δ m 13 2 + Δ m 23 2 oscillation. There are still good prospects for future reactor neutrino experiments after them. For example, there is room to further improve sin 2 2 θ 13 accuracy at a baseline of ∼1.5 km, a very precise sin 2 2 θ 12 measurement and the determination of mass hierarchy may be possible at a baseline ∼50 km, and if KamLAND is enlarged to the SuperKamiokande size, better measurement of Δ m 12 2 and sin 2 2 θ 12 will be anticipated. It is important to take into account such possibilities when planning future neutrino program after θ 13 is measured by current experiments.