Status of the T2K long baseline neutrino oscillation experiment

The T2K experiment is a long baseline neutrino oscillation experiment. The main goals of the experiment are a measurement of the neutrino mixing angle θ₁₃ by the observation of electron neutrino appearance and a precise measurement of θ₂₃ and mass difference by the observation of muon neutrino disappearance. Construction of the neutrino beamline has recently been completed; production of the first neutrino beam was confirmed by observing muons produced by the proton beam. In this paper, the T2K physics goals and the status of preparations toward the start of the experiment in fall 2009 are reported.