Probing Non-Standard Neutrino Interactions with Neutrino Factories

TL;DR

This paper evaluates how neutrino factories can detect non-standard neutrino interactions (NSI) through muon appearance measurements, demonstrating their potential to discover NSI and measure lepton mixing parameters precisely.

Contribution

It introduces a two-detector setup at different distances to improve sensitivity to NSI and resolve parameter degeneracies, advancing neutrino factory capabilities.

Findings

High sensitivity to off-diagonal NSI parameters for small 

Two-detector configuration effectively resolves -NSI confusion

Neutrino factories can serve as discovery tools for NSI while measuring mixing parameters

Abstract

We discuss the sensitivity reach of a neutrino factory measurement to non-standard neutrino interactions (NSI), which may exist as a low-energy manifestation of physics beyond the Standard Model. We use the muon appearance mode \nu_e --> \nu_\mu and consider two detectors, one at 3000 km and the other at 7000 km. Assuming the effects of NSI at the production and the detection are negligible, we discuss the sensitivities to NSI and the simultaneous determination of \theta_{13} and \delta by examining the effects in the neutrino propagation of various systems in which two NSI parameters \epsilon_{\alpha \beta} are switched on. The sensitivities to off-diagonal \epsilon's are found to be excellent up to small values of \theta_{13}. We demonstrate that the two-detector setting is powerful enough to resolve the \theta_{13}-NSI confusion problem. We believe that the results obtained in this paper open the door to the possibility of using neutrino factory as a discovery machine for NSI while keeping its primary function of performing precision measurements of the lepton mixing parameters.