Non-standard interaction effect on $CP$ violation in neutrino oscillation with super-beam

TL;DR

This study explores how non-standard neutrino interactions influence the ability to detect $CP$ violation in neutrino oscillation experiments with super-beams, highlighting conditions where NSIs can enhance or obscure $CP$ violation signals.

Contribution

It provides a detailed analysis of the impact of non-standard neutrino interactions on $CP$ violation discovery potential in super-beam experiments, including effects of complex NSIs.

Findings

NSIs $oldsymbol{ ext{ε}_{eμ}}$ and $oldsymbol{ ext{ε}_{eτ}}$ significantly affect oscillation probabilities.

Certain NSI phases can suppress observable $CP$ violation regardless of the Dirac phase.

NSIs can improve $CP$ violation discovery reach if their values are well known.

Abstract

We have studied the $CP$ violation discovery reach in neutrino oscillation experiment with superbeam in presence of non-standard interactions of neutrinos with matter for both short and long baselines. For the most important channel of oscillation ($\nu_\mu \rightarrow \nu_e$) for $CP$ violation discovery there is significant effect in the oscillation probability particularly due to NSIs' $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ for longer baseline and higher energy in comparison to other NSIs'. Interestingly for these two NSIs' (for real and higher allowed values) there is possibility of better discovery reach of $CP$ violation than that with only Standard Model interactions of neutrinos with matter provided that NSI values are known. For complex NSIs' we have shown the $CP$ violation discovery reach in the plane of Dirac phase $\delta$ and NSI phase $\phi_{ij}$. Our analysis indicates that for some values of some NSI phases total $CP$ violation may not be observable for any values of $\delta $.