Optimization of the baseline and the parent muon energy for a low energy neutrino factory

TL;DR

This paper optimizes the setup of a low energy neutrino factory by analyzing muon energies and baselines to maximize discovery potential for ,  CP phase, and mass hierarchy, considering recent  indications.

Contribution

It provides a detailed analysis of optimal muon energies and baselines for neutrino factories to enhance discovery sensitivity for key neutrino parameters.

Findings

Sensitivity increases with parent muon energy, saturating at higher energies.

Longer baselines require higher saturation energies for optimal sensitivity.

For large , shorter baselines (~1500-2500 km) are optimal for hierarchy and  discovery.

Abstract

We discuss the optimal setup for a low energy neutrino factory in order to achieve a 5\sigma-discovery of a nonzero mixing angle \theta_{13}, a nonzero CP phase \delta_{CP}, and the mass hierarchy. We explore parent muon energies in the range 5--16 GeV, and baselines in the range 500--5000 km. We present the results in terms of the reach in sin^2\theta_{13}, emphasizing the dependence of the optimal baseline on the true value of \delta_{CP}. We show that the sensitivity of a given setup typically increases with parent muon energy, reaching saturation for higher energies. The saturation energy is larger for longer baselines; we present an estimate of this dependence. In the light of the recent indications of a large \theta_{13}, we also determine how these preferences would change if indeed a large \theta_{13} is confirmed. In such a case, the baselines ~2500 km (~1500 km) may be expected to lead to hierarchy determination (\delta_{CP} discovery) with the minimum exposure.