Impact of the Dresden-II and COHERENT neutrino scattering data on neutrino electromagnetic properties and electroweak physics

TL;DR

This paper analyzes recent neutrino scattering data from Dresden-II and COHERENT to refine constraints on neutrino electromagnetic properties and electroweak parameters, providing updated limits and a low-energy measurement of the weak mixing angle.

Contribution

It offers the first combined analysis of Dresden-II and COHERENT data to improve bounds on neutrino properties and measures the weak mixing angle at low energy.

Findings

Set a new best upper limit on the electron neutrino charge radius.

Significantly improved limits on neutrino electric charge and magnetic moment.

Provided a low-energy measurement of the weak mixing angle.

Abstract

Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) represents a powerful tool to investigate key electroweak physics parameters and neutrino properties since its first observation in 2017 by the COHERENT experiment exploiting the spallation neutron source at Oak Ridge National Laboratory. In light of the recent detection of such a process with antineutrinos produced by the Dresden-II reactor scattering off a germanium detector, we revisit the limits so far set on the neutrino magnetic moments, charge radii and millicharges as well as on the weak mixing angle. In order to do so, we also include the contribution of elastic neutrino-electron scattering, whose effect becomes non negligible in some beyond the Standard Model theories. By using different hypotheses for the germanium quenching factor and the reactor antineutrino flux, we provide a measurement of the weak mixing angle at the low-energy scale of the Dresden-II reactor experiment and, thanks to a combined analysis with the latest cesium iodide and argon data set released by the COHERENT Collaboration, we deliver updated limits for the neutrino electromagnetic properties. Interestingly, we are able to set a new best upper limit on the electron neutrino charge radius and significantly improve the other CE$\nu$NS-related limits on the neutrino electric charge and magnetic moment.