Probing neutrino magnetic moments at Spallation Neutron Source facilities

TL;DR

This paper explores how the COHERENT experiment at the Spallation Neutron Source can improve measurements of neutrino magnetic moments and other electromagnetic properties, offering potential for new physics insights.

Contribution

It demonstrates the potential of the COHERENT experiment to significantly enhance sensitivity to neutrino magnetic moments and perform precise Standard Model tests at low energies.

Findings

Can improve existing neutrino magnetic moment limits by half an order of magnitude

Enables competitive measurements of the weak mixing angle

Probes other electromagnetic neutrino properties like charge-radius

Abstract

Majorana neutrino electromagnetic properties are studied through neutral current coherent neutrino-nucleus scattering. We focus on the potential of the recently planned COHERENT experiment at the Spallation Neutron Source to probe muon-neutrino magnetic moments. The resulting sensitivities are determined on the basis of a chi^2 analysis employing realistic nuclear structure calculations in the context of the quasi-particle random phase approximation. We find that they can improve existing limits by half an order of magnitude. In addition, we show that these facilities allow for Standard Model precision tests in the low energy regime, with a competitive determination of the weak mixing angle. Finally, they also offer the capability to probe other electromagnetic neutrino properties, such as the neutrino charge-radius. We illustrate our results for various choices of experimental setup and target material.