CP-Violating and Charged Current Neutrino Non-standard Interactions in CE$\nu$NS

TL;DR

This paper explores how non-standard neutrino interactions, especially CP-violating phases and charged current effects, influence coherent neutrino scattering measurements and their implications for neutrino oscillation experiments.

Contribution

It introduces a detailed analysis of charged current and CP-violating NSI effects in CE$ u$NS and derives new constraints from COHERENT data, highlighting their impact on neutrino oscillation parameter interpretations.

Findings

COHERENT data constrains charged current NSI but needs more data for stronger limits.

CP-phase effects depend heavily on phase values, affecting NSI parameter limits.

COHERENT provides complementary constraints relevant to neutrino oscillation anomalies.

Abstract

Neutrino non-standard interactions (NSI) can be constrained using coherent elastic neutrino-nucleus scattering. We discuss here two aspects in this respect, namely the effects of (i) charged current NSI in neutrino production and (ii) CP-violating phases associated with neutral current NSI in neutrino detection. Effects of CP-phases require the simultaneous presence of two different flavor-changing neutral current NSI parameters. Applying these two scenarios to the COHERENT measurement, we derive limits on charged current NSI and find that more data is required to compete with the existing limits. Regarding CP-phases, we show how the limits on the NSI parameters depend dramatically on the values of the phases. Accidentally, the same parameters influencing coherent scattering also show up in neutrino oscillation experiments. We find that COHERENT provides complementary constraints on the set of NSI parameters that can explain the discrepancy in the best-fit value of the standard CP-phase obtained by T2K and NO$\nu$A, while the significance with which the LMA-Dark solution is ruled out can be weakened by the presence of additional NSI parameters introduced here.