Detecting CP Violation in the Presence of Non-Standard Neutrino Interactions

TL;DR

This paper investigates how non-standard neutrino interactions can cause ambiguities in detecting CP violation in long baseline experiments, and explores methods to resolve these degeneracies using biprobability plots and energy spectrum analysis.

Contribution

It introduces a combined numerical and perturbative approach to analyze oscillation probabilities with NSI and visualizes CP phase degeneracies on biprobability plots.

Findings

Energy spectrum analysis at DUNE can distinguish CP violation scenarios.

Biprobability plots effectively visualize CP phase degeneracies.

Broad energy ranges help resolve ambiguities caused by NSI.

Abstract

New physics beyond the Standard Model could appear at long baseline oscillation experiments as non-standard interactions (NSI) between neutrinos and matter. If so, determination of the CP-violating phase $\delta_{13}$ is ambiguous due to interference with additional complex phases. I'll present my work using both numerical solutions and a perturbative approach to study oscillation probabilities in the presence of NSI. I'll show how the CP phase degeneracies are visualized on biprobability plots, and the extent to which the energy spectrum for a given baseline length can help resolve them. In particular, this shows how the broad range of energies at DUNE would help distinguish between maximal, standard CP violation and the absence of CP violation with large $\epsilon_{e\tau}$.