DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over ...antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals.
Description of the data release 10.13139/OLCF/1969085 (https://doi.ccs.ornl.gov/ui/doi/426) from the measurements of the CsINa 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.
The LUX-ZEPLIN (LZ) experiment is a dark matter detector centered on a dual-phase xenon time projection chamber. We report searches for new physics appearing through few-keV-scale electron recoils, ...using the experiment's first exposure of 60 live days and a fiducial mass of 5.5t. The data are found to be consistent with a background-only hypothesis, and limits are set on models for new physics including solar axion electron coupling, solar neutrino magnetic moment and millicharge, and electron couplings to galactic axion-like particles and hidden photons. Similar limits are set on weakly interacting massive particle (WIMP) dark matter producing signals through ionized atomic states from the Migdal effect.
A primary goal of the upcoming Deep Underground Neutrino Experiment (DUNE) is to measure the \(\mathcal{O}(10)\) MeV neutrinos produced by a Galactic core-collapse supernova if one should occur ...during the lifetime of the experiment. The liquid-argon-based detectors planned for DUNE are expected to be uniquely sensitive to the \(\nu_e\) component of the supernova flux, enabling a wide variety of physics and astrophysics measurements. A key requirement for a correct interpretation of these measurements is a good understanding of the energy-dependent total cross section \(\sigma(E_\nu)\) for charged-current \(\nu_e\) absorption on argon. In the context of a simulated extraction of supernova \(\nu_e\) spectral parameters from a toy analysis, we investigate the impact of \(\sigma(E_\nu)\) modeling uncertainties on DUNE's supernova neutrino physics sensitivity for the first time. We find that the currently large theoretical uncertainties on \(\sigma(E_\nu)\) must be substantially reduced before the \(\nu_e\) flux parameters can be extracted reliably: in the absence of external constraints, a measurement of the integrated neutrino luminosity with less than 10\% bias with DUNE requires \(\sigma(E_\nu)\) to be known to about 5%. The neutrino spectral shape parameters can be known to better than 10% for a 20% uncertainty on the cross-section scale, although they will be sensitive to uncertainties on the shape of \(\sigma(E_\nu)\). A direct measurement of low-energy \(\nu_e\)-argon scattering would be invaluable for improving the theoretical precision to the needed level.
Phys. Rev. Lett. 131, 221801 (2023) Using an 185-kg NaITl array, COHERENT has measured the inclusive
electron-neutrino charged-current cross section on ^{127}$I with pion
decay-at-rest neutrinos ...produced by the Spallation Neutron Source at Oak Ridge
National Laboratory. Iodine is one the heaviest targets for which low-energy
($\leq$ 50 MeV) inelastic neutrino-nucleus processes have been measured, and
this is the first measurement of its inclusive cross section. After a five-year
detector exposure, COHERENT reports a flux-averaged cross section for electron
neutrinos of $9.2^{+2.1}_{-1.8} \times 10^{-40}$ cm$^2$. This corresponds to a
value that is $\sim$41% lower than predicted using the MARLEY event generator
with a measured Gamow-Teller strength distribution. In addition, the observed
visible spectrum from charged-current scattering on $^{127}$I has been measured
between 10 and 55 MeV, and the exclusive zero-neutron and one-or-more-neutron
emission cross sections are measured to be $5.2^{+3.4}_{-3.1} \times 10^{-40}$
and $2.2^{+3.5}_{-2.2} \times 10^{-40}$ cm$^2$, respectively.
The LUX-ZEPLIN experiment recently reported limits on WIMP-nucleus interactions from its initial science run, down to \(9.2\times10^{-48}\) cm\(^2\) for the spin-independent interaction of a 36 ...GeV/c\(^2\) WIMP at 90% confidence level. In this paper, we present a comprehensive analysis of the backgrounds important for this result and for other upcoming physics analyses, including neutrinoless double-beta decay searches and effective field theory interpretations of LUX-ZEPLIN data. We confirm that the in-situ determinations of bulk and fixed radioactive backgrounds are consistent with expectations from the ex-situ assays. The observed background rate after WIMP search criteria were applied was \((6.3\pm0.5)\times10^{-5}\) events/keV\(_{ee}\)/kg/day in the low-energy region, approximately 60 times lower than the equivalent rate reported by the LUX experiment.
The COHERENT collaboration searched for scalar dark matter particles produced at the Spallation Neutron Source with masses between 1 and 220~MeV/c\(^2\) using a CsINa scintillation detector sensitive ...to nuclear recoils above 9~keV\(_\text{nr}\). 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 \(\alpha_D<0.64\), 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.
Phys. Rev. D 108, 072001 (2023) Using neutrinos produced at the Spallation Neutron Source (SNS) at Oak Ridge
National Laboratory (ORNL), the COHERENT collaboration has studied the
Pb($\nu_e$,X$n$) ...process with a lead neutrino-induced-neutron (NIN) detector.
Data from this detector are fit jointly with previously collected COHERENT data
on this process. A combined analysis of the two datasets yields a cross section
that is $0.29^{+0.17}_{-0.16}$ times that predicted by the MARLEY event
generator using experimentally-measured Gamow-Teller strength distributions,
consistent with no NIN events at 1.8$\sigma$. This is the first inelastic
neutrino-nucleus process COHERENT has studied, among several planned exploiting
the high flux of low-energy neutrinos produced at the SNS.
We present results of several measurements of CsINa scintillation response to 3-60 keV energy nuclear recoils performed by the COHERENT collaboration using tagged neutron elastic scattering ...experiments and an endpoint technique. Earlier results, used to estimate the coherent elastic neutrino-nucleus scattering (CEvNS) event rate for the first observation of this process achieved by COHERENT at the Spallation Neutron Source (SNS), have been reassessed. We discuss corrections for the identified systematic effects and update the respective uncertainty values. The impact of updated results on future precision tests of CEvNS is estimated. We scrutinize potential systematic effects that could affect each measurement. In particular we confirm the response of the H11934-200 Hamamatsu photomultiplier tube (PMT) used for the measurements presented in this study to be linear in the relevant signal scale region.
We find that it is possible to increase sensitivity to low energy physics in a third or fourth DUNE-like module with careful controls over radiopurity and some modifications to a detector similar to ...the DUNE Far Detector design. In particular, sensitivity to supernova and solar neutrinos can be enhanced with improved MeV-scale reach. A neutrinoless double beta decay search with \(^{136}\)Xe loading appears feasible. Furthermore, sensitivity to Weakly-Interacting Massive Particle (WIMP) Dark Matter (DM) becomes competitive with the planned world program in such a detector, offering a unique seasonal variation detection that is characteristic for the nature of WIMPs.
