Wednesday 1 May 2013 

Speaker: Thomas Dealtry (Oxford University)


Title: "Latest oscillation results from T2K" 

Abstract: T2K is a second-generation long-baseline neutrino-oscillation 
experiment using the 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 very 
precise measurements of the mixing angle \theta_{23} and of the atmospheric 
squared-mass splitting, and to measure \theta_{13} via electron neutrino 
appearance (complementary to the reactor experiment electron antineutrino 
disappearance).

I will present results from the oscillation analyses on the full dataset 
collected up July 2012. This dataset corresponds to an integrated JPARC 
neutrino-beam exposure of 3.010E+20 protons-on-target. The analyses provide 
the world's best measurement on \theta_{23}, and compelling evidence for 
electron neutrino appearance via \theta_{13}.