166 research outputs found
First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon
We report the first measurement of coherent elastic neutrino-nucleus
scattering (\cevns) on argon using a liquid argon detector at the Oak Ridge
National Laboratory Spallation Neutron Source. Two independent analyses prefer
\cevns over the background-only null hypothesis with greater than
significance. The measured cross section, averaged over the incident neutrino
flux, is (2.2 0.7) 10 cm -- consistent with the
standard model prediction. The neutron-number dependence of this result,
together with that from our previous measurement on CsI, confirms the existence
of the \cevns process and provides improved constraints on non-standard
neutrino interactions.Comment: 8 pages, 5 figures with 2 pages, 6 figures supplementary material V3:
fixes to figs 3,4 V4: fix typo in table 1, V5: replaced missing appendix, V6:
fix Eq 1, new fig 3, V7 final version, updated with final revision
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Sensitivity of the COHERENT experiment to accelerator-produced dark matter
The COHERENT experiment is well poised to test sub-GeV dark matter models using detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the + decay-at-rest (-DAR) neutrino beam produced by the Spallation Neutron Source. We show a planned 750-kg single-phase liquid argon scintillation detector would place leading limits on scalar light dark matter models for dark matter particles produced through vector and leptophobic portals in the absence of other effects beyond the standard model. The characteristic timing profile of a -DAR beam allows a unique opportunity for constraining systematic uncertainties on the standard model background using a time window where dark matter signal is not expected, enhancing expected sensitivity. Additionally, we discuss future prospects which show that an on-axis CEvNS detector would probe the thermal abundance for a scalar dark matter candidate for all couplings ′ ≤1 for 15 MeV dark matter with just 1.0 tonne-yr of exposure with increased exposure testing a wider range of dark matter masses and spins
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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 . 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 protons on target. The dataset provided constraints on beam-related backgrounds critical for future measurements and yielded candidate CEvNS events which implies a cross section for the process, averaged over the SNS pion decay-at-rest flux, of , 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
First Probe of Sub-GeV Dark Matter Beyond the Cosmological Expectation with the COHERENT CsI Detector at the SNS
The COHERENT collaboration searched for scalar dark matter particles produced
at the Spallation Neutron Source with masses between 1 and 220~MeV/c using
a CsI[Na] scintillation detector sensitive to nuclear recoils above
9~keV. No evidence for dark matter is found and we thus place
limits on allowed parameter space. With this low-threshold detector, we are
sensitive to coherent elastic scattering between dark matter and nuclei. The
cross section for this process is orders of magnitude higher than for other
processes historically used for accelerator-based direct-detection searches so
that our small, 14.6~kg detector significantly improves on past constraints. At
peak sensitivity, we reject the flux consistent with the cosmologically
observed dark-matter concentration for all coupling constants ,
assuming a scalar dark-matter particle. We also calculate the sensitivity of
future COHERENT detectors to dark-matter signals which will ambitiously test
multiple dark-matter spin scenarios
Monitoring the SNS basement neutron background with the MARS detector
We present the analysis and results of the first dataset collected with the
MARS neutron detector deployed at the Oak Ridge National Laboratory Spallation
Neutron Source (SNS) for the purpose of monitoring and characterizing the
beam-related neutron (BRN) background for the COHERENT collaboration. MARS was
positioned next to the COH-CsI coherent elastic neutrino-nucleus scattering
detector in the SNS basement corridor. This is the basement location of closest
proximity to the SNS target and thus, of highest neutrino flux, but it is also
well shielded from the BRN flux by infill concrete and gravel. These data show
the detector registered roughly one BRN per day. Using MARS' measured detection
efficiency, the incoming BRN flux is estimated to be
for neutron energies
above ~MeV and up to a few tens of MeV. We compare our results with
previous BRN measurements in the SNS basement corridor reported by other
neutron detectors.Comment: Submitted to JINS
Connecting the dots between brand experience and brand loyalty: The mediating role of brand personality and brand relationships
This article critically examines consumer–brand relationships from the perspective of interpersonal relationship theory. Specifically, the authors investigate the relationship between brand experience and the two components of brand loyalty, namely purchase brand loyalty and attitudinal brand loyalty. The study also examines the link between brand experience and brand relationship variables, brand trust, brand attachment and brand commitment. In addition, the mediating role of brand personality and brand commitment in the relationship between brand experience and brandloyalty is investigated. Drawing on the results of an empirical cross-brand study from three product categories, the authors demonstrate that brand experience, brand personality and brand relationship variables (brand attachment and brand commitment) all affect the degree to which a consumer is loyal to a brand. On the basis of the findings, the authors offer guidelines to managers on how to build and sustain purchase and attitudinal brand loyalty by enhancing brand experience. The theoretical and managerial significance of the findings together with directions for future research are discussed
COHERENT Collaboration data release from the measurements of CsI[Na] response to nuclear recoils
Description of the data release 10.13139/OLCF/1969085
(https://doi.ccs.ornl.gov/ui/doi/426) from the measurements of the CsI[Na]
response to low energy nuclear recoils by the COHERENT collaboration. The
release corresponds to the results published in "D. Akimov et al 2022 JINST 17
P10034". We share the data in the form of raw ADC waveforms, provide benchmark
values, and share plots to enhance the transparency and reproducibility of our
results. This document describes the contents of the data release as well as
guidance on the use of the data
First Constraint on Coherent Elastic Neutrino-Nucleus Scattering in Argon
Coherent elastic neutrino-nucleus scattering (CEvNS) is the dominant neutrino
scattering channel for neutrinos of energy 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
protons on target. The dataset yielded observed CEvNS events implying a
cross section for the process, averaged over the SNS pion decay-at-rest flux,
of cm, 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
Development of a Kr source for the calibration of the CENNS-10 Liquid Argon Detector
We report on the preparation of and calibration measurements with a
Kr source for the CENNS-10 liquid argon detector.
Kr atoms generated in the decay of a Rb source were
introduced into the detector via injection into the Ar circulation loop.
Scintillation light arising from the 9.4 keV and 32.1 keV conversion electrons
in the decay of Kr in the detector volume were then observed.
This calibration source allows the characterization of the low-energy response
of the CENNS-10 detector and is applicable to other low-energy-threshold
detectors. The energy resolution of the detector was measured to be 9 at
the total Kr decay energy of 41.5 keV. We performed an
analysis to separately calibrate the detector using the two conversion
electrons at 9.4 keV and 32.1 keVComment: v2: As accepted to JINS
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