P. S. Barbeau
A5084889245- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Quantum, superfluid, helium dynamics
- Cosmology and Gravitation Theories
- Photocathodes and Microchannel Plates
- Nuclear Physics and Applications
- Nuclear physics research studies
- CCD and CMOS Imaging Sensors
- Particle accelerators and beam dynamics
- Radioactive contamination and transfer
- Scientific Research and Discoveries
- Atmospheric Ozone and Climate
- Graphite, nuclear technology, radiation studies
- Nuclear reactor physics and engineering
- Climate Change Communication and Perception
- Noncommutative and Quantum Gravity Theories
- Medical Imaging Techniques and Applications
- Lightning and Electromagnetic Phenomena
- High-Voltage Power Transmission Systems
- Luminescence Properties of Advanced Materials
Duke University
2015-2024
Triangle Universities Nuclear Laboratory
2015-2024
University of Chicago
2003-2018
Stanford University
2010-2014
Fermi National Accelerator Laboratory
2011-2013
University of Illinois Chicago
2008-2009
We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, number of cosmogenic peaks can be observed for first time. discuss irreducible excess bulklike events below 3 keV ionization energy. These could caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible determine their origin. Improved constraints are...
The coherent elastic scattering of neutrinos off nuclei has eluded detection for four decades, even though its predicted cross section is by far the largest all low-energy neutrino couplings. This mode interaction offers new opportunities to study properties and leads a miniaturization detector size, with potential technological applications. We observed this process at 6.7σ confidence level, using low-background, 14.6-kilogram CsI[Na] scintillator exposed emissions from Spallation Neutron...
Fifteen months of cumulative CoGeNT data are examined for indications an annual modulation, a predicted signature weakly interacting massive particle (WIMP) interactions. Presently available support the presence modulated component unknown origin, with parameters prima facie compatible galactic halo composed light-mass WIMPs. Unoptimized estimators yield statistical significance modulation ∼2.8σ, limited by short exposure.
We report on a search for neutrinoless double-beta decay of $^{136}$Xe with EXO-200. No signal is observed an exposure 32.5 kg-yr, background ~1.5 x 10^{-3} /(kg yr keV) in the $\pm 1\sigma$ region interest. This sets lower limit half-life $T_{1/2}^{0\nu\beta\beta}$($^{136}$Xe) > 1.6 10$^{25}$ (90% CL), corresponding to effective Majorana masses less than 140-380 meV, depending matrix element calculation.
CoGeNT employs p-type point-contact (PPC) germanium detectors to search for Weakly Interacting Massive Particles (WIMPs). By virtue of its low energy threshold and ability reject surface backgrounds, this type device allows an emphasis on low-mass dark matter candidates (wimp mass about 10 GeV/c2). We report the characteristics PPC detector presently taking data at Soudan Underground Laboratory, elaborating aspects shielding, acquisition, instrumental stability, analysis, background...
A search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{136}$Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between $0\nu\beta\beta$ and background events. Relative previous analyses, signal detection efficiency has been raised from 80.8% 96.4$\pm$3.0% energy resolution of detector at Q-value improved $\sigma/E=1.23\%$ $1.15\pm0.02\%$ upgraded detector. Accounting new data, median 90% confidence level half-life sensitivity this analysis...
Results from a search for neutrinoless double-beta decay (0νββ) of ^{136}Xe are presented using the first year data taken with upgraded EXO-200 detector. Relative to previous searches by EXO-200, energy resolution detector has been improved σ/E=1.23%, electric field in drift region raised 50%, and system suppress radon volume between cryostat lead shielding implemented. In addition, analysis techniques that improve topological discrimination 0νββ background events have developed....
We report the first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) on argon using a liquid detector at Oak Ridge National Laboratory Spallation Neutron Source. Two independent analyses prefer CEvNS over background-only null hypothesis with greater than $3\ensuremath{\sigma}$ significance. The measured cross section, averaged incident neutrino flux, is $(2.2\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}39}\text{ }\text{...
The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-β decay in ^{76}Ge. Demonstrator comprises 44.1 kg (29.7 enriched ^{76}Ge) split between two modules contained a low background shield at the Sanford Underground Research Facility Lead, South Dakota. Here we present results from data taken during construction, commissioning, and start full operations. We achieve unprecedented energy resolution 2.5 keV FWHM Q_{ββ} very with no...
We measured the cross section of coherent elastic neutrino-nucleus scattering (CEvNS) using a CsI[Na] scintillating crystal in high flux neutrinos produced at Spallation Neutron Source Oak Ridge National Laboratory. New data collected before detector decommissioning have more than doubled dataset since first observation CEvNS, achieved with this detector. Systematic uncertainties also been reduced an updated quenching model, allowing for improved precision. With these analysis improvements,...
A new type of radiation detector, a p-type modified electrode germanium diode, is presented. It shown that the prototype displays, for first time, combination features (mass, energy threshold and background expectation) required measurement coherent neutrino–nucleus scattering in nuclear reactor experiment. First results are presented from its calibration using sub-kiloelectronvolt recoils similar to those expected antineutrinos or light WIMPs (weakly interacting massive particles) beyond...
We report the observation of two-neutrino double-beta decay in Xe-136 with T_1/2 = 2.11 +- 0.04 (stat.) 0.21 (sys.) x 10^21 yr. This second order process, predicted by Standard Model, has been observed for several nuclei but not Xe-136. The rate provides new input to matrix element calculations and search more interesting neutrino-less decay, most sensitive probe existence Majorana particles measurement neutrino mass scale.
We report on an improved measurement of the $2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ half-life ${}^{136}$Xe performed by EXO-200. The use a large and homogeneous time-projection chamber allows for precise estimate fiducial mass used measurement, resulting in small systematic uncertainty. also discuss detail data-analysis methods double-$\ensuremath{\beta}$ decay searches with EXO-200, while emphasizing those directly related to present measurement. is found be...
A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type germanium detector to conclusively rule out standard isothermal galactic halo weakly interacting massive particles as explanation annual modulation effect leading claim. Bounds are similarly imposed on suggestion that pseudoscalars might lead effect. describe sensitivity light achievable with our device, particular, next-to-minimal supersymmetric model candidates.
EXO-200 is an experiment designed to search for double beta decay of $^{136}$Xe with a single-phase, liquid xenon detector. It uses active mass 110 kg enriched 80.6% in the isotope 136 ultra-low background time projection chamber capable simultaneous detection ionization and scintillation. This paper describes detector particular attention most innovative aspects design that revolve around reduction backgrounds, efficient use expensive isotopically xenon, optimization energy resolution...
The next-generation Enriched Xenon Observatory (nEXO) is a proposed experiment to search for neutrinoless double beta ($0\nu\beta\beta$) decay in $^{136}$Xe with target half-life sensitivity of approximately $10^{28}$ years using $5\times10^3$ kg isotopically enriched liquid-xenon time projection chamber. This improvement two orders magnitude over current limits obtained by significant increase the mass, monolithic and homogeneous configuration active medium, multi-parameter measurements...
The projected performance and detector configuration of nEXO are described in this pre-Conceptual Design Report (pCDR). is a tonne-scale neutrinoless double beta ($0νββ$) decay search $^{136}$Xe, based on the ultra-low background liquid xenon technology validated by EXO-200. With $\simeq$ 5000 kg enriched to 90% isotope 136, has half-life sensitivity approximately $10^{28}$ years. This represents an improvement about two orders magnitude with respect current results. Based experience gained...
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_{nr}. No evidence is found we thus place limits on allowed parameter space. With this low-threshold detector, are coherent elastic scattering nuclei. cross section process orders of magnitude higher than other processes historically used accelerator-based...
Weakly Interacting Massive Particles (WIMPs) are well-established dark matter candidates. WIMP interactions with sensitive detectors expected to display a characteristic annual modulation in rate. We release dataset spanning 3.4 years of operation from low-background germanium detector, designed search for this signature. A previously reported persists, concentrated region the energy spectrum populated by an exponential excess unknown origin. Its phase and period agree phenomenological...
Now that conventional weakly interacting massive particle (WIMP) dark matter searches are approaching the neutrino floor, there has been a resurgence of interest in detectors with sensitivity to nuclear recoil directions. A large-scale directional detector is attractive it would have below be capable unambiguously establishing galactic origin purported signal, and could serve dual purpose as observatory. We present first detailed analysis 1000 m$^3$-scale measuring signal at low energies....
The COHERENT experiment is well poised to test sub-GeV dark matter models using low-energy recoil detectors sensitive coherent elastic neutrino-nucleus scattering (CEvNS) in the $\pi$-DAR neutrino beam produced by Spallation Neutron Source. We show how a planned 750-kg liquid argon scintillation detector would place leading limits on scalar light models, over two orders of magnitude mass, for particles through vector and leptophobic portals absence other effects beyond standard model....
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory provides an intense, high-quality source of neutrinos from pion decay rest. This was recently used for the first measurements coherent elastic neutrino–nucleus scattering (CEvNS) by COHERENT Collaboration, which resulted in new constraints physics beyond Standard Model. SNS neutrino will enable further CEvNS measurements, exploration inelastic interactions particular relevance understanding supernova neutrinos, and searches...