Exploring NSI degeneracies in long-baseline experiments

TL;DR

This paper investigates how non-standard interactions (NSI) create degeneracies in long-baseline neutrino experiments, complicating the measurement of CP violation and exploring ways to distinguish NSI effects from standard oscillations.

Contribution

It provides an exact analytical formulation of appearance probabilities in the presence of NSI and analyzes parameter regions with degeneracies affecting CP phase determination.

Findings

Identifies parameter regions with degeneracies in NSI scenarios.

Discusses potential methods to falsify NSI parameters in experiments.

Highlights challenges in measuring CP violation due to NSI effects.

Abstract

One of the main purposes of long-baseline neutrino experiments is to unambiguously measure the CP violating phase in the neutrino sector within the three neutrino oscillation picture. In the presence of physics beyond the Standard Model, the determination of the CP phase will be more difficult, due to the already known degeneracy problem. Working in the framework of non-standard interactions (NSI), we compute the appearance probabilities in an exact analytical formulation and analyze the region of parameters where the confusion problem is present. We also discuss some cases where the falsification of the NSI parameters can be done in long-baseline experiments.