Measurement of the neutron radius of argon via CEνNS

Coherent elastic neutrino-nucleus scattering (CEvNS) is a useful interaction for testing properties of the Standard Model. The COHERENT collaboration is currently constructing a 750 kilogram liquid Argon detector (COH-Ar-750) for deployment in 2025, following the first measurement on Argon in 2020. One property of interest and not well-known for most isotopes is the distribution of neutrons in the nucleus, parameterized as the "neutron radius". The new CEvNS detector, together with the high flux of neutrinos from the SNS will collect thousands of events per year which can yield a first measurement of the argon neutron radius. A model of the CEvNS cross section, together with GEANT4 Monte Carlo simulation, was used to determine the expected experimental sensitivity to the argon neutron radius. This result along with projected event rates will be presented and discussed.