Very Long Baseline Neutrino Oscillation Experiment for Precise Determination of Oscillation Parameters and Search for nu_mu -> nu_e Appearance and CP Violation

TL;DR

This paper proposes a very long baseline neutrino experiment using high-energy proton sources and large underground detectors to precisely measure neutrino oscillation parameters and search for CP violation in the neutrino sector.

Contribution

It introduces a novel experimental setup with a baseline over 2500 km, combining high-intensity neutrino beams and large detectors to improve measurement precision of oscillation parameters and CP violation detection.

Findings

Precise measurement of dm^2_32 and sin^2(2theta_23)

High sensitivity to sin^2(2theta_13) for CP violation detection

Ability to distinguish mass hierarchy using neutrino and anti-neutrino modes

Abstract

The possibility of making a low cost, very intense (1MW) high energy proton source at the Brookhaven Alternating Gradient Synchrotron (BNL-AGS) along with the forthcoming new large underground detectors (approaching 1 MT in mass) at the National Underground Science and Engineering Laboratory (NUSEL) in Homestake, South Dakota or at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, allows us to propose a program of experiments that will address fundamental aspects of neutrino oscillations and CP-invariance violation. This program is unique because of the very long baseline of more than 2500 km from BNL to the underground laboratory in the West. We used the running scenario of a low energy, wide band neutrino beam with 1 MW AGS, 500 kT of fiducial mass water Cherenkov detector, and 5x10^7 seconds of running time. In this report we show that with these conditions we precisely measure dm^2_32 and sin^2(2theta_23) and have excellent sensitivity to sin^2(2theta_13) with a distinctive signal spectrum. If sin^2(2theta_13) > 0.01 the experiment is sensitive to the CP-violating phase in the mixing matrix with only neutrino running. By running in the anti-neutrino mode we distinguish between the cases dm^2_31 > 0 versus dm^2_31 < 0 using distinctive distortions to the electron or positron spectrum. Lastly, the very long baseline allows the measurement of dm^2_21 (in the LMA region) with approximately the same resolution as KAMLAND but in the nu_mu -> nu_e appearance channel.