Resolve the Neutrino Parameter Degeneracies with the T2K Off-axis Beam and the Large Detector in Korea

Abstract

In this talk, we show the physics impacts of putting a large Water Cerenkov detector in Korea during the T2K experimental period. The T2K experiment which will start in 2009 plans to use the high intensity conventional neutrino beam from J-PARC at Tokai village, Japan. The center of this beam will reach the sea level between Japan and Korea, and an off-axis beam at 0.5^o to 1.0^o can be observed in Korea. For a combination of the 3^o off-axis beam at SK with baseline length L=295km and the 0.5^o off-axis beam in the east coast of Korea, near Gyeongju, at L=1000km, we find that the neutrino mass hierarchy (the sign of the larger mass-squared difference) can be resolved and the CP phase of the MNS unitary matrix can be constrained uniquely at 3-sigma level when sin^2(2theta_rct) simgt 0.06.