Neutrino-nucleus coherent scattering as a probe of neutron density distributions

TL;DR

This paper demonstrates that neutrino-nucleus coherent scattering can precisely measure neutron density distributions, including higher moments, using neutrino fluxes and detector data, thus providing a new method to test nuclear models.

Contribution

It introduces a novel approach to extract neutron density moments from neutrino scattering data, extending beyond the neutron radius to higher moments like the fourth.

Findings

Neutron radii can be measured with a few percent uncertainty.

Higher moments of neutron distributions can be distinguished with accurate flux normalization.

Neutrino scattering can discriminate among nuclear energy functional predictions.

Abstract

Neutrino-nucleus coherent elastic scattering provides a theoretically appealing way to measure the neutron part of nuclear form factors. Using an expansion of form factors into moments, we show that neutrinos from stopped pions can probe not only the second moment of the form factor (the neutron radius) but also the fourth moment. Using simple Monte Carlo techniques for argon, germanium, and xenon detectors of 3.5 tonnes, 1.5 tonnes, and 300 kg, respectively, we show that the neutron radii can be found with an uncertainty of a few percent when near a neutrino flux of $3\times10^{7}$ neutrinos/cm$^{2}$/s. If the normalization of the neutrino flux is known independently, one can determine the moments accurately enough to discriminate among the predictions of various nuclear energy functionals.