arXiv subjects

J. Newby

Publications and source records attributed to J. Newby.

At least 19 recordsLinked to original sources

arXiv2026

The Eos detector: a demonstrator of hybrid optical detection technology

Eos is an R&D testbed for hybrid detector technologies, featuring state-of-the-art sub-ns photosensors, the first implementation of dichroicons in a large-scale demonstrator, and the deployment of novel detection media such as water-based liquid scintillator (WbLS). By separating Cherenkov and scintillation light, Eos leverages the benefits of both to explore the potential of next-generation neutrino technologies. An extensive radioactive source calibration program enables the characterization of position, direction, and energy reconstruction performance of a variety of target materials. Furthermore, Eos will provide data to refine optical models and inform the development and simulation of future neutrino experiments. This paper describes the as-built design and data-taking plan of Eos, outlining its scientific motivations and role in the development of future detector technologies.

physics.ins-det↗

arXiv2026

Neutrino monitoring of explosions for excluding fission yield

Nuclear fission produces neutrinos, so the absence of a neutrino signal can be used to set a limit on the fission content of an explosion. This capability could be employed on former nuclear test sites to assure regulators, international monitors, or other observers that activities involving chemical explosions do not exceed a designated limit for nuclear fission. This paper quantifies the neutrino detector masses that would be required to set fission yield limits at source-to-detector distances up to 100 km, assuming detection by inverse beta decay with realistic background levels. The analysis indicates that detectors with active mass in the ton- to tens-of-kiloton range can set potentially useful limits on the fission yield of large chemical explosions at the Nevada National Security Site. In contrast, inverse beta decay detectors are not well suited to excluding fission yield at longer range or in the subcritical nuclear experiments that have occurred at some test sites following the cessation of explosive nuclear testing.

physics.soc-ph↗

arXiv2026

Performance of the Eos detector with water

In this manuscript we present the first results from Eos, a four tonne optical detector located at the University of California, Berkeley. The primary goal of Eos is to demonstrate the performance capabilities of scintillation-based, 'hybrid' detector technology for future neutrino detectors. The data presented were collected while both the inner target vessel and the outer buffer vessel were filled with water. The water target acts as a well-understood medium that produces only Cherenkov light, which can be used to calibrate and develop the detector model and reconstruction algorithms prior to the deployment of scintillating material. Using deployed optical and radioactive calibration sources, a series of detailed detector calibrations are performed. These enable a suite of tests for various reconstruction algorithms. Simulations that use calibrated models are compared with the data across a variety of different types of calibration sources, source positions, and rotations.

hep-ex↗

arXiv2026

Measurement of coherent elastic neutrino nucleus scattering on germanium by COHERENT

The COHERENT collaboration reports the most precise measurement of the coherent elastic neutrino-nucleus scattering cross section to date. This measurement was performed with COHERENT's germanium detector array, Ge-Mini, at the Spallation Neutron Source at Oak Ridge National Laboratory. A cumulative exposure of $4.68\times10^{22}$ protons on target yielded a total number of observed counts of $124^{+14}_{-12}$ and a flux-averaged cross section of $1.00 \pm 0.10 \mathrm{(statistical)} \pm 0.10 \mathrm{(systematic)}$ relative to the standard-model expectation of $5.9\times10^{-39} \mathrm{cm}^2$. The well-understood energy and timing distributions of the neutrino source allow for independent measurements of muon- and electron-neutrino scattering rates. This information is used to improve constraints on non-standard neutrino interactions mediated by heavy particles.

hep-ex↗

arXiv2026

The COHERENT Experiment: 2026 Update

The COHERENT experiment measures neutrino-induced recoils from coherent elastic neutrino-nucleus scattering (CEvNS) with multiple nuclear targets at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL), USA. Several successful CEvNS measurements have been achieved in recent years with tens-of-kg detector masses, with a CsI scintillating crystal, a liquid argon single-phase detector, and high-purity germanium spectrometers. For the next phase, COHERENT aims at high-statistics detection of CEvNS events for precision tests of the standard model of particle physics, and to probe new physics beyond-the-standard model. Percent-level precision can be achieved by lowering thresholds, reducing backgrounds, and by scaling up the detector masses. It goes hand in hand with benchmarking the neutrino flux from the SNS. Further detectors will measure CEvNS in additional nuclei, including lighter target nuclei such as sodium and neon, to continue to test the expected neutron-number-squared dependence of the cross section. COHERENT can furthermore study charged-current and neutral-current inelastic neutrino-nucleus cross sections on various nuclei at neutrino energies below $\sim$50 MeV. Many of these cross sections have never been measured before, but are critical input for the interpretation of core-collapse supernova detection in large-scale neutrino experiments such as DUNE, Super-K, Hyper-K, and HALO.

hep-ex↗

arXiv2025

Evidence of Coherent Elastic Neutrino-Nucleus Scattering with COHERENT's Germanium Array

We report the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) on natural germanium, measured at the Spallation Neutron Source at Oak Ridge National Laboratory. The Ge-Mini detector of the COHERENT collaboration employs large-mass, low-noise, high-purity germanium spectrometers, enabling excellent energy resolution, and an analysis threshold of 1.5 keV electron-equivalent ionization energy. We observe a on-beam excess of 20.6 +7.1 -6.3 counts with a total exposure of 10.22 GWhkg and we reject the no-CEvNS hypothesis with 3.9 sigma significance. The result agrees with the predicted standard model of particle physics signal rate within 2 sigma.

hep-ex↗

arXiv2025

A prototype reactor-antineutrino detector based on $^6$Li-doped pulse-shaping-discriminating plastic scintillator

An aboveground 60-kg reactor-antineutrino detector prototype, comprised of a 2-dimensional array of 36 $^{6}$Li-doped pulse shape sensitive plastic scintillator bars, is described. Each bar is 50~cm long with a square cross section of 5.5~cm. Doped with $^{6}$Li at 0.1\% by mass, the detector is capable of identifying correlated energy depositions for the detection of reactor antineutrinos via the inverse-beta-decay reaction. Each bar is wrapped with a specular reflector that directs photons towards PMTs mounted at both ends of the bar. This paper highlights the construction, key features, and main performance characteristics of the system. The system, which relies on multiple observables such as PSD, energy, position, and timing, is capable of detecting IBD-like neutron-correlated backgrounds, long-lived decay chains, and cosmogenic isotopes.

physics.ins-det↗

arXiv2025

Fundamental Nuclear and Particle Physics At Neutron Sources

Fundamental neutron and neutrino physics at neutron sources, combining precision measurements and theory, can probe new physics at energy scales well beyond the highest energies probed by the LHC and possible future high energy collider facilities. The European Spallation Source (ESS) will in the not too far future be a most powerful pulsed neutron source and simultaneously the world's brightest pulsed neutrino source. The ESS, and neutron sources in general, can provide unprecedented and unique opportunities to contribute to the search for the missing elements in the Standard Model of particle physics. Currently there are no strong indications where hints of the origin of the new physics will emerge. A multi-pronged approach will provide the fastest path to fill the gaps in our knowledge and neutron sources have a pivotal role to play. To survey the ongoing and proposed physics experiments at neutron sources and assess their potential impact, a workshop was held at Lund University in January, 2025. This report is a summary of that workshop and has been prepared as input to the European Strategy Update.

nucl-ex↗

arXiv2024

Measurement of the Electron-Neutrino Charged-Current Cross Sections on ${}^{127}$I with the COHERENT NaI$ν$E detector

Using an 185-kg NaI[Tl] 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.

nucl-ex↗

arXiv2023

Accessing new physics with an undoped, cryogenic CsI CEvNS detector for COHERENT at the SNS

We consider the potential for a 10-kg undoped cryogenic CsI detector operating at the Spallation Neutron Source to measure coherent elastic neutrino-nucleus scattering and its sensitivity to discover new physics beyond the standard model. Through a combination of increased event rate, lower threshold, and good timing resolution, such a detector would significantly improve on past measurements. We considered tests of several beyond-the-standard-model scenarios such as neutrino non-standard interactions and accelerator-produced dark matter. This detector's performance was also studied for relevant questions in nuclear physics and neutrino astronomy, namely the weak charge distribution of CsI nuclei and detection of neutrinos from a core-collapse supernova.

hep-ex↗

arXiv2023

Measurement of ${}^{nat}$Pb($ν_e$,X$n$) production with a stopped-pion neutrino source

Using neutrinos produced at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), the COHERENT collaboration has studied the Pb($ν_e$,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$σ$. 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.

hep-ex↗

arXiv2023

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.

physics.ins-det↗

arXiv2023

Electron Scattering and Neutrino Physics

A thorough understanding of neutrino-nucleus scattering physics is crucial for the successful execution of the entire US neutrino physics program. Neutrino-nucleus interaction constitutes one of the biggest systematic uncertainties in neutrino experiments - both at intermediate energies affecting long-baseline Deep Underground Neutrino Experiment (DUNE), as well as at low energies affecting coherent scattering neutrino program - and could well be the difference between achieving or missing discovery level precision. To this end, electron-nucleus scattering experiments provide vital information to test, assess and validate different nuclear models and event generators intended to be used in neutrino experiments. In this white paper, we highlight connections between electron- and neutrino-nucleus scattering physics at energies ranging from 10s of MeV to a few GeV, review the status of ongoing and planned electron scattering experiments, identify gaps, and layout a path forward that benefits the neutrino community. We also highlight the systemic challenges with respect to the divide between the nuclear and high-energy physics communities and funding that presents additional hurdle in mobilizing these connections to the benefit of neutrino programs.

hep-ex↗

arXiv2023

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$^2$ using a CsI[Na] 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 $α_D<0.64$, 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.

hep-ex↗

arXiv2022

Snowmass Neutrino Frontier: Neutrino Interaction Cross Sections (NF06) Topical Group Report

A thorough understanding of neutrino cross sections in a wide range of energies is crucial for the successful execution of the entire neutrino physics program. In order to extract neutrino properties, long-baseline experiments need an accurate determination of neutrino cross sections within their detector(s). Since very few of the needed neutrino cross sections across the energy spectrum are directly measured, we emphasize the need for theoretical input and indirect measurements such as electron scattering, which would complement direct measurements. In this report we briefly summarize the current status of our knowledge of the neutrino cross sections and articulate needs of the experiments, ongoing and planned, at energies ranging from CEvNS and supernova neutrino energies to the DUNE and atmospheric neutrino energies.

hep-ex↗

arXiv2022

Measurement of scintillation response of CsI[Na] to low-energy nuclear recoils by COHERENT

We present results of several measurements of CsI[Na] 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.

physics.ins-det↗

arXiv2022

Physics Opportunities in the ORNL Spallation Neutron Source Second Target Station Era

The Oak Ridge National Laboratory (ORNL) Spallation Neutron Source (SNS) First Target Station (FTS), used by the COHERENT experiment, provides an intense and extremely high-quality source of pulsed stopped-pion neutrinos, with energies up to about 50 MeV. Upgrades to the SNS are planned, including a Second Target Station (STS), which will approximately double the expected neutrino flux while maintaining quality similar to the FTS source. Furthermore, additional space for ten-tonne scale detectors may be available. We describe here exciting opportunities for neutrino physics, other particle and nuclear physics, and detector development using the FTS and STS neutrino sources.

hep-ex↗

arXiv2022

Measurement of the Coherent Elastic Neutrino-Nucleus Scattering Cross Section on CsI by COHERENT

We measured the cross section of coherent elastic neutrino-nucleus scattering (\cevns{}) using a CsI[Na] scintillating crystal in a high flux of neutrinos produced at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. New data collected before detector decommissioning has more than doubled the dataset since the first observation of \cevns{}, achieved with this detector. Systematic uncertainties have also been reduced with an updated quenching model, allowing for improved precision. With these analysis improvements, the COHERENT collaboration determined the cross section to be $(165^{+30}_{-25})\times10^{-40}$~cm$^2$, consistent with the standard model, giving the most precise measurement of \cevns{} yet. The timing structure of the neutrino beam has been exploited to compare the \cevns{} cross section from scattering of different neutrino flavors. This result places leading constraints on neutrino non-standard interactions while testing lepton flavor universality and measures the weak mixing angle as $\sin^2θ_{W}=0.220^{+0.028}_{-0.026}$ at $Q^2\approx(50\text{ MeV})^2$

hep-ex↗