Exploring Source and Detector Non-Standard Neutrino Interactions at ESS$\nu$SB

TL;DR

This study assesses how non-standard neutrino interactions at the ESS$ u$SB experiment affect measurements of neutrino properties, finding that some parameters are robust while others are significantly impacted, especially without a near detector.

Contribution

It provides the first detailed analysis of source and detector non-standard neutrino interactions at ESS$ u$SB, including sensitivity estimates and the impact of detector configurations.

Findings

Precision of $ heta_{23}$ measurement remains robust.

Sensitivity to certain non-standard parameters is comparable or improved.

Absence of a near detector reduces sensitivity to non-standard interactions.

Abstract

We investigate source and detector non-standard neutrino interactions at the proposed ESS$\nu$SB experiment. We analyze the effect of non-standard physics at the probability level, the event-rate level and by a full computation of the ESS$\nu$SB setup. We find that the precision measurement of the leptonic mixing angle $\theta_{23}$ at ESS$\nu$SB is robust in the presence of non-standard interactions, whereas that of the leptonic CP-violating phase $\delta$ is worsened at most by a factor of two. We compute sensitivities to all the relevant source and decector non-standard interaction parameters and find that the sensitivities to the parameters $\varepsilon^s_{\mu e}$ and $\varepsilon^d_{\mu e}$ are comparable to the existing limits in a realistic scenario, while they improve by a factor of two in an optimistic scenario. Finally, we show that the absence of a near detector compromises the sensitivity of ESS$\nu$SB to non-standard interactions.