First constraint on coherent elastic neutrino-nucleus scattering in argon

Coherent elastic neutrino-nucleus scattering (CEvNS) is calculated to be the dominant neutrino scattering channel for neutrinos of energy $E_ν$ < 100 MeV . We report a limit for this process from data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the pion decay-at-rest neutrino source at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) with 4.2 × 10$^{22}$ protons on target. The dataset provided constraints on beam-related backgrounds critical for future measurements and yielded < 7.4 candidate CEvNS events which implies a cross section for the process, averaged over the SNS pion decay-at-rest flux, of < 3.4 × 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[Na] nonstandard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon

COHERENT 2018 at the Spallation Neutron Source

The primary goal of the COHERENT collaboration is to measure and study coherent elastic neutrino-nucleus scattering (CEvNS) using the high-power, few-tens-of-MeV, pulsed source of neutrinos provided by the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The COHERENT collaboration reported the first detection of CEvNS [Akimov:2017ade] using a CsI[Na] detector. At present the collaboration is deploying four detector technologies: a CsI[Na] scintillating crystal, p-type point-contact germanium detectors, single-phase liquid argon, and NaI[Tl] crystals. All detectors are located in the neutron-quiet basement of the SNS target building at distances 20-30 m from the SNS neutrino source. The simultaneous measurement in all four COHERENT detector subsystems will test the $N^2$ dependence of the cross section and search for new physics. In addition, COHERENT is measuring neutrino-induced neutrons from charged- and neutral-current neutrino interactions on nuclei in shielding materials, which represent a non-negligible background for CEvNS as well as being of intrinsic interest. The Collaboration is planning as well to look for charged-current interactions of relevance to supernova and weak-interaction physics. This document describes concisely the COHERENT physics motivations, sensitivity, and next plans for measurements at the SNS to be accomplished on a few-year timescale

First constraint on coherent elastic neutrino-nucleus scattering in argon

Coherent elastic neutrino-nucleus scattering (CEvNS) is calculated to be the dominant neutrino scattering channel for neutrinos of energy E-nu < 100 MeV. We report a limit for this process from data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the pion decay-at-rest neutrino source at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) with 4.2 x 10(22) protons on target. The dataset provided constraints on beam-related backgrounds critical for future measurements and yielded < 7.4 candidate CEvNS events which implies a cross section for the process, averaged over the SNS pion decay-at-rest flux, of < 3.4 x 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[Na] nonstandard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon. c. American Physical Society11Nsciescopu