Abstract

T2K is a second-generation long-baseline neutrino oscillation experiment using the new high-intensity muon-neutrino beam produced at Japan Proton Accelerator Research Complex (JPARC). Sitting 295 km away, at an off-axis angle of 2.5 degrees, the giant Super-Kamiokande water Cherenkov detector sees a narrow band beam peaked at 600 MeV. The baseline to energy ratio is finely tuned for studying neutrino oscillations at the so-called atmospheric neutrino squared-mass splitting. The beam is also sampled 280 m downstream of the neutrino production target by a series of finely-segmented solid-scintillator and time-projection-chamber detectors. Observing changes in the neutrino beam between the two detectors allows oscillation parameters to be accurately extracted.

The main goal of the T2K experiment is to produce the first measurement of the neutrino mixing angle \theta_{13} and very precise measurements of the mixing angle \theta_{23} and of the atmospheric squared-mass splitting.

I will present results from the muon-neutrino disappearance and electron-neutrino appearance analyses on the dataset collected during the first physics run which spanned the period from January to June 2010. This first T2K dataset corresponds to an integrated JPARC neutrino-beam exposure of 3.23E+19 protons-on-target.