First Constraint on Coherent Elastic Neutrino-Nucleus Scattering in Argon

TL;DR

This paper reports the first experimental limit on coherent elastic neutrino-nucleus scattering (CEvNS) using a liquid argon detector near the SNS, confirming the process's cross section is within twice the Standard Model prediction.

Contribution

It provides the first CEvNS limit with an argon detector and demonstrates the feasibility of detecting CEvNS in liquid argon.

Findings

Set an upper limit on CEvNS cross section in argon

Confirmed CEvNS cross section within twice the Standard Model

Demonstrated liquid argon detector's viability for CEvNS detection

Abstract

Coherent elastic neutrino-nucleus scattering (CEvNS) is the dominant neutrino scattering channel for neutrinos of energy $E_\nu < 100$ MeV. We report a limit for this process using data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the Oak Ridge National Laboratory Spallation Neutron Source (SNS) Hg target with $4.2\times 10^{22}$ protons on target. The dataset yielded $< 7.4$ observed CEvNS events implying a cross section for the process, averaged over the SNS pion decay-at-rest flux, of $<3.4 \times 10^{-39}$ cm$^{2}$, a limit within twice the Standard Model prediction. This is the first limit on CEvNS from an argon nucleus and confirms the earlier CsI non-standard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon.