KamLAND and T2K

KamLAND announced the first evidence of ν ̄ e disappearance, followed by direct evidence for neutrino oscillation by observing distortion of the reactor ν ̄ e energy spectrum, demonstrated almost two cycles of the periodic feature expected neutrino oscillation, and determined a precise value for the neutrino oscillation parameter Δ m 12 2 and stringent constraints on θ 12 . KamLAND also succeeded in detecting geoneutrinos produced by natural radioactivities in the Earth. This detection allows better estimation of the abundances and distributions of radioactive elements in the Earth and of the Earth’s overall heat generation. In the J-PARC neutrino facility, T2K is ready for operation. T2K is supposed to give critical information, which guides the future direction of the neutrino physics. The current status of T2K is shown.