Neutrino factory optimization for non-standard interactions

TL;DR

This paper analyzes how to optimize neutrino factory setups for detecting non-standard neutrino interactions, finding that the existing IDS-NF configuration is nearly optimal and emphasizing the importance of very long baselines.

Contribution

It provides a comprehensive analysis of neutrino factory optimization considering non-standard interactions, including all parameters and phases, and evaluates the impact of different detector channels and baselines.

Findings

Silver channel detector offers limited benefit unless muon energy is increased.

IDS-NF setup is nearly optimal even with non-standard interactions.

Very long baselines are crucial for detecting certain non-standard parameters.

Abstract

We study the optimization of a neutrino factory with respect to non-standard neutral current neutrino interactions, and compare the results to those obtained without non-standard interactions. We discuss the muon energy, baselines, and oscillation channels as degrees of freedom. Our conclusions are based on both analytical calculations and on a full numerical simulation of the neutrino factory setup proposed by the international design study (IDS-NF). We consider all possible non-standard parameters, and include their complex phases. We identify the impact of the different parameters on the golden, silver, and disappearance channels. We come to the conclusion that, even in the presence of non-standard interactions, the performance of the neutrino factory hardly profits from a silver channel detector, unless the muon energy is significantly increased compared to the IDS-NF setup. Apart from the dispensable silver channel detector, we demonstrate that the IDS-NF setup is close to optimal even if non-standard interactions are considered. We find that one very long baseline is a key component in the search for non-standard interactions, in particular for |\epsilon^m_{\mu\tau}| and |\epsilon^m_{\tau\tau}|.