Neutrino millicharge and other electromagnetic interactions with COHERENT-2021 data

TL;DR

This paper uses new COHERENT experiment data to set tighter constraints on neutrino electromagnetic properties, especially millicharge, revealing its unique low-energy behavior and interference effects.

Contribution

It provides the first detailed analysis of neutrino millicharge effects with improved experimental data, highlighting its dependence on recoil energy and target mass.

Findings

Enhanced statistical significance of neutrino scattering detection (11.6σ)

Constraints on neutrino electromagnetic properties improved by over twofold

Identification of the unique low-energy recoil behavior of neutrino millicharge

Abstract

We analyze new data from the COHERENT experiment of the coherent neutrino-nucleus scattering to investigate the electromagnetic interactions of neutrinos. With almost double the statistics and precision now, the statistical significance of the observed process has now enhanced to 11.6$\sigma$. We derive constraints on the electromagnetic properties of neutrinos using the new COHERENT data. The constraints improve by more than a factor of two compared to the previous bounds. Furthermore, we discuss the unique behavior of the neutrino millicharge at lower energy recoils and show its unique dependence on its interference with the standard model contribution, inverse power of recoil energy and the mass of the target particle in comparison to the other interactions.