In this paper, we study the combined sensitivity of T2K-II and NOvA, the world leading long-baseline neutrino oscillation experiments, to CP violation in lepton sector. By operating until the year 2026, T2K-II is expected to collect a total exposure of 20×1021 protons-on-target. Meanwhile, NOνA experiment has a plan to extend its run up to 2024 for accumulating totally an amount of 72 × 1020 protons-on-target. | Communications in Physics, Vol. 28, No. 4 (2018), pp. 337-349 DOI: COMBINED SENSITIVITY OF T2K-II AND NOνA EXPERIMENTS TO CP VIOLATION IN LEPTON SECTOR TRAN VAN NGOC1 , CAO VAN SON2 , AND NGUYEN THI HONG VAN1,3,† 1 Institute For Interdisciplinary Research in Science and Education (IFIRSE) Ghenh Rang, Quy Nhon, Vietnam 2 High Energy Accelerator Research Organization (KEK) Tsukuba, Ibaraki, Japan 3 Institute of Physics, Vietnam Academy of Science and Technology 10 Dao Tan, Ba Dinh, Hanoi, Vietnam † E-mail: nhvan@ Received 04 August 2018 Accepted for publication 21 September 2018 Published 15 December 2018 Abstract. In this paper, we study the combined sensitivity of T2K-II and NOvA, the world leading long-baseline neutrino oscillation experiments, to CP violation in lepton sector. By operating until the year 2026, T2K-II is expected to collect a total exposure of 20 × 1021 protons-on-target. Meanwhile, NOνA experiment has a plan to extend its run up to 2024 for accumulating totally an amount of 72 × 1020 protons-on-target. By combining analyses of T2K-II and NOνA with an ultimate constraint on θ13 from reactor, the sensitivity to CP violation is expected to exceed 4σ . It is also pointed out that by reducing the systematic uncertainties of both T2K-II and NOνA to a level of 2%, the sensitivity to CP violation will significantly increase with a discovery possibility at 5σ . significance for a particular range of true δCP . Keywords: CP violation, neutrinos, T2K experiment, NOvA experiment. Classification numbers: , , . I. INTRODUCTION The idea of neutrino oscillation, in which one type of neutrino can change into another, was raised for the first time by B. Pontecorvo in 1957 as neutrino-antineutrino transition [1]. It can explain the solar neutrino anomaly [2, 3] and the atmospheric neutrino anomaly [4]. The neutrino flavor oscillation was introduced later in 1962 by Z. Maki, M. Nakagawa and
