COHERENT 2018 at the Spallation Neutron Source

Abstract

collaboration is deploying four detector technologies: a CsI[Na] scintillating crystal, p-type pointcontact 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.

CP-Violating and Charged Current Neutrino Non-standard Interactions in CE$ν$NS

“…Coherent elastic neutrino-nucleon scattering (CEνNS) is an allowed standard model (SM) process which was predicted in the seventies [1,2] and was observed very recently by the COHERENT experiment [3][4][5]. In between the theoretical prediction and its observation, the formalism to use CEνNS as a probe for new neutrino physics, new neutral current physics or nuclear physics was pointed out for several scenarios [6][7][8][9][10][11][12][13][14][15][16][17].…”

“…Neutrinos are provided from pions decaying at rest, which in turn are produced from the spallation neutron source. The data we will use in this paper was collected with a total number of 1.76 × 10 23 of protons on target (pot) delivered to liquid mercury [3][4][5]. Monoenergetic muon neutrinos (ν µ ) at E ν = 29.8 MeV are produced isotropically from pion decay at rest (π + → µ + ν µ ) followed by a delayed isotropic flux of electron neutrinos (ν e ) and muon anti-neutrinos (ν µ ) produced subsequently by muon-decay at rest (µ + → ν e e + νµ ).…”

First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon

“…A CEvNS observation requires detectors with a low nuclear-recoil-energy threshold in a low-background environment with an intense neutrino flux. The COHER-ENT collaboration has deployed a suite of detectors in a dedicated neutrino laboratory ("Neutrino Alley") at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) [34,35]. We have reported the first observation of CEvNS using a 14.6 kg, low-background, low-threshold CsI[Na] detector 19.3 m from the SNS target [34].…”

Sailing the CE$ν$NS Seas of Non-Standard Neutrino Interactions with the Coherent CAPTAIN Mills Experiment

“…As a rough treatment, we take these to be a 10% overall uncertainty on the flux normalization. These assumptions are conservatively based on COHERENT [48], though it is expected that CCM will benefit from an enhanced background rejection capability at the Lujan facility.…”