$\theta_{13}$, $\delta$ and the neutrino mass hierarchy at a $\gamma=350$ double baseline Li/B $\beta$-Beam

TL;DR

This paper analyzes the potential of a high-energy beta-beam neutrino experiment with two detectors at different baselines to measure neutrino mixing parameters, mass hierarchy, and CP violation with high sensitivity.

Contribution

It introduces a detailed feasibility study of a $eta$-Beam setup at $ ext{γ}=350$ with two detectors, evaluating its sensitivity to key neutrino oscillation parameters.

Findings

Sensitivity to $ heta_{13}$ down to $ ext{sin}^2 2 heta_{13} ext{ } ext{~} 2 imes 10^{-4}$.

Mass hierarchy can be determined for $ ext{sin}^2 2 heta_{13} ext{ } ext{~} 4 imes 10^{-4}$.

CP violation can be discovered in 70% of the $ ext{δ}$ space for $ ext{sin}^2 2 heta_{13} ext{ } ext{~} 10^{-3}$.

Abstract

We consider a $\beta$-Beam facility where $^8$Li and $^8$B ions are accelerated at $\gamma = 350$, accumulated in a 10 Km storage ring and let decay, so as to produce intense $\bar \nu_e$ and $\nu_e$ beams. These beams illuminate two iron detectors located at $L \simeq 2000$ Km and $L \simeq 7000$ Km, respectively. The physics potential of this setup is analysed in full detail as a function of the flux. We find that, for the highest flux ($10 \times 10^{18}$ ion decays per year per baseline), the sensitivity to $\theta_{13}$ reaches $\sin^2 2 \theta_{13} \geq 2 \times10^{-4}$; the sign of the atmospheric mass difference can be identified, regardless of the true hierarchy, for $\sin^2 2 \theta_{13} \geq 4\times10^{-4}$; and, CP-violation can be discovered in 70% of the $\delta$-parameter space for $\sin^2 2 \theta_{13} \geq 10^{-3}$, having some sensitivity to CP-violation down to $\sin^2 2 \theta_{13} \geq 10^{-4}$ for $|\delta| \sim 90^\circ$.