NuFact15 : XVII International Workshop on Neutrino Factories and Future Neutrino Facilities

Revisiting T2KK and T2KO physics potential and nu_mu - anti-nu_mu beam ratio

Not scheduled

20m

Ministro João Alberto Lins de Barros auditorium (Centro Brasileiro de Pesquisas Físicas)

Poster Working group 1: Neutrino Oscillation Physics

Speaker

Dr Yoshitaro Takaesu (University of Tokyo)

Description

In this presentation, we revisit the sensitivity studies of a Tokai-to-Kamioka-and-Korea (T2KK) and Tokai-to-Kamioka-and-Oki (T2KO) proposals where a 100 kton detector is placed in Korea (L = 1000 km) and Oki island (L = 653 km) in Japan, respectively, in addition to the Super-Kamiokande (SK) for determination of the neutrino mass hierarchy and leptonic CP phase (δCP). We systematically study the nu_mu and anti-nu_mu focusing beam ratio with dedicated estimation of backgrounds for the nu_e appearance and nu_mu disappearance signals, especially improving treatment of the neutral current (NC) pi0 backgrounds. Using a nu_m : anti-nu_mu beam ratio between 3 : 2 and 2.5 : 2.5, the mass hierarchy determination with Delta_chi^2 = 10−30 by the T2KK and 3−20 by the T2KO experiment are expected for 5×10^21POT when sin(θ23)^2 = 0.5. The CP phase is measured with the uncertainty of 20 deg. − 50 deg. by the T2KK and T2KO using the nu_mu : anti-nu_mu focusing beam ratio between 3.5 : 1.5 and 1.5 : 3.5. These findings indicate that the T2KK and T2KO experiments can improve their sensitivity to both the mass hierarchy determination and leptonic CP phase measurement simultaneously, using nu_mu and anti-nu_mu focusing beams with 3 : 2 - 2.5 : 2.5 beam ratio.