Neutrino Factory Superbeam

TL;DR

This paper proposes an optimized neutrino factory combined with a superbeam to enhance neutrino oscillation measurements, emphasizing low muon energies, combined detection channels, and shared infrastructure for improved performance.

Contribution

It introduces the concept of a neutrino factory superbeam, integrating low-energy muon decay beams with superbeam technology for superior experimental results.

Findings

The combined setup outperforms standalone low-energy neutrino factories.

Using the same baseline reduces matter density uncertainties.

The configuration allows for efficient use of existing detector technology.

Abstract

We discuss the optimization of a neutrino factory for large \sin^2 2 \theta_{13}, where we assume minimum effort on the accelerator side. This implies that we use low muon energies for the price of an optimized detection system. We demonstrate that such a neutrino factory performs excellent if combined with the electron neutrino appearance channel. Instead of the platinum channel operated with the muon neutrinos from the muon decays, we propose to use the initial superbeam from the decaying pions and kaons, which might be utilized at little extra effort. Since we assume out-of-phase bunches arriving at the same detector, we do not require electron charge identification. In addition, we can choose the proton energy such that we obtain a synergistic spectrum peaking at lower energies. We find that both the superbeam and the neutrino factory beam should used at the identical baseline to reduce matter density uncertainties, possibly with the same detector. This effectively makes the configuration a single experiment, which we call ``neutrino factory superbeam''. We demonstrate that this experiment outperforms a low-energy neutrino factory or a wide band beam alone beyond a simple addition of statistics.