A5070269126- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- CCD and CMOS Imaging Sensors
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Radiation Detection and Scintillator Technologies
- Astronomy and Astrophysical Research
- Radiation Therapy and Dosimetry
- Advanced Memory and Neural Computing
- Advanced Thermodynamics and Statistical Mechanics
- Scientific Research and Discoveries
- Neural Networks and Applications
- Stellar, planetary, and galactic studies
- Superconducting and THz Device Technology
- Enhanced Oil Recovery Techniques
- Astronomical Observations and Instrumentation
- Oil and Gas Production Techniques
- Animal Behavior and Reproduction
- Avian ecology and behavior
- American Constitutional Law and Politics
- Thermal properties of materials
- Distributed Control Multi-Agent Systems
Fermi National Accelerator Laboratory
2017-2025
University of Chicago
2019-2024
Sulzer (United Kingdom)
2024
Northwestern University
2015-2020
UNSW Canberra
2020
UNSW Sydney
2020
University of Canberra
2020
Baxter (United States)
2017
University of Ottawa
2013
Pfizer (United Kingdom)
2010
New results are reported from the operation of PICO-60 dark matter detector, a bubble chamber filled with 52 kg C_{3}F_{8} located in SNOLAB underground laboratory. As previous PICO chambers, exhibits excellent electron recoil and alpha decay rejection, observed multiple-scattering neutron rate indicates single-scatter background less than one event per month. A blind analysis an efficiency-corrected 1167-kg day exposure at 3.3-keV thermodynamic threshold reveals no single-scattering nuclear...
New data are reported from the operation of a 2 liter ${\mathrm{C}}_{3}{\mathrm{F}}_{8}$ bubble chamber in SNOLAB underground laboratory, with total exposure 211.5 kg days at four different energy thresholds below 10 keV. These show that provides excellent electron-recoil and alpha rejection capabilities very low thresholds. The exhibits an sensitivity $<3.5\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}10}$ factor $>98.2%$. also include first observation dependence acoustic signal on...
Final results are reported from operation of the PICO-60 C$_3$F$_8$ dark matter detector, a bubble chamber filled with 52 kg located in SNOLAB underground laboratory. The was operated at thermodynamic thresholds as low 1.2 keV without loss stability. A new blind 1404-kg-day exposure 2.45 threshold acquired approximately same expected total background rate previous 1167-kg-day 3.3 keV. This increased is enabled part by optical tracking analysis to better identify events near detector walls,...
We report direct-detection constraints on light dark matter particles interacting with electrons. The results are based a method that exploits the extremely low levels of leakage current DAMIC detector at SNOLAB 2-6$\times$10$^{-22}$ A cm$^{-2}$. evaluate charge distribution pixels collect $<10~\rm{e^-}$ for contributions beyond may be attributed to interactions. Constraints placed so-far unexplored parameter space masses between 0.6 and 100 MeV$c^{-2}$. also present new hidden-photon in...
The field of dark matter detection is a highly visible and competitive one. In this paper, we propose recommendations for presenting direct results particularly suited weak-scale searches, although believe the spirit can apply more broadly to searches other candidates, such as very light or axions. To translate experimental data into final published result, collaborations must make series choices in their analysis, ranging from how model astrophysical parameters statistical inferences based...
Many low-threshold experiments observe sharply rising event rates of yet unknown origins below a few hundred eV, and larger than expected from known backgrounds. Due to the significant impact this excess on dark matter or neutrino sensitivity these experiments, collective effort has been started share knowledge about individual observations. For this, EXCESS Workshop was initiated. In its first iteration in June 2021, ten rare search collaborations contributed initiative via talks...
We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed an integrated exposure 85.23 g days, and exploits subelectron charge resolution low level current charge-coupled devices (CCDs). Dark-matter-induced ionization signals above detector are searched for in CCD pixels up to 7e^{-}. With this dataset we place limits mass between 0.53 1000 MeV/c^{2}, excluding unexplored regions...
In recent years, the lack of a conclusive detection WIMP dark matter at 10 GeV/c$^{2}$ mass scale and above has encouraged development low-threshold detector technology aimed probing lighter candidates. Detectors based on Cooper-pair-breaking sensors have emerged as promising avenue for this due to low (meV-scale) energy required breaking Cooper pair in most superconductors. Among them, devices superconducting qubits are interesting candidates sensing their observed sensitivity broken pairs....
The PICO collaboration reports results obtained by PICO-2L Run-2 after carefully controlling for particulate contamination. data clearly indicates that previously observed anomalies were due to contamination in the bubble chamber fluid. These observations set new bounds on spin-dependent scattering of dark matter, and help pave way larger scale experiments.
New data are reported from the operation of PICO-60 dark matter detector, a bubble chamber filled with 36.8 kg CF$_3$I and located in SNOLAB underground laboratory. is largest to search for date. With an analyzed exposure 92.8 livedays, exhibits same excellent background rejection observed smaller chambers. Alpha decays exhibit frequency-dependent acoustic calorimetry, similar but not identical that recently C$_3$F$_8$ chamber. also observes large population unknown events, exhibiting...
There are currently several existing and proposed experiments designed to probe sub-GeV dark matter (DM) using electron ionization in various materials. The projected signal rates for these assume that this yield arises only from DM scattering directly off targets, ignoring secondary contributions nuclear targets. We investigate the validity of assumption show if couples with comparable strength both protons electrons, as would be case a photon mediator, atomic via Migdal effect scales...
The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it also generate largest pulsed neutrino flux suitable detection of Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS), a process recently measured first time at ORNL's Neutron Source. We describe innovative detector technologies maximally able profit from order-of-magnitude increase in provided by ESS, along with...
We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg-day target exposure DAMIC experiment at SNOLAB underground laboratory. The observed energy spectrum and spatial distribution ionization events with electron-equivalent energies $>$200 eV$_{\rm ee}$ in CCDs are consistent backgrounds natural radioactivity. An excess is above analysis threshold 50 ee}$. While origin this low-energy requires further investigation, our data exclude...
Dark matter (DM) particles with sufficiently large cross sections may scatter as they travel through Earth’s bulk. The corresponding changes in the DM flux give rise to a characteristic daily modulation signal detectors sensitive DM-electron interactions. Here, we report results obtained from first underground operation of DAMIC-M prototype detector searching for such MeV-scale mass. A model-independent analysis finds no rate <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...
The search for particle-like dark matter with meV-to-GeV masses has developed rapidly in the past few years. We summarize science case these searches, recent progress, and exciting upcoming opportunities. Funding Research Development a portfolio of small projects will allow community to capitalize on substantial advances theory experiment probe vast regions unexplored dark-matter parameter space coming decade.
Results from working analog VLSI implementations of two different pulse stream neural network forms are reported. The circuits rendered relatively invariant to processing variations, and the problem cascadability synapses form large systems is addressed. A strategy for interchip communication numbers states has been implemented in silicon results presented. demonstrated confront many issues that blight massively parallel systems, offer solutions.< <ETX...
We present a novel unifying interpretation of excess event rates observed in several dark matter direct-detection experiments that utilize single-electron threshold semiconductor detectors. Despite their different locations, exposures, readout techniques, detector composition, and operating depths, these all observe statistically significant $\sim$ 10 Hz/kg. However, none persistent excesses has yet been reported as signal because individually, each can be attributed to well-motivated but...
We construct the first comprehensive radioactive background model for a dark matter search with charge-coupled devices (CCDs). leverage well-characterized depth and energy resolution of DAMIC at SNOLAB detector detailed geant4-based particle-transport simulation to both bulk surface backgrounds from natural radioactivity down 50 eVee. fit distributions observed ionization events differentiate constrain possible sources, example, 3H silicon cosmogenic activation 210Pb radon plate-out. observe...
The Migdal effect has received much attention from the dark matter direct detection community, in particular due to its power setting leading limits on sub-GeV particle matter. However, it is crucial obtain experimental confirmation of through nuclear scattering using Standard Model probes. In this work, we extend existing calculations case neutron-nucleus scattering, with a focus neutron angle distributions silicon. We identify kinematic regimes wherein assumptions present current hold for...
We present results from a 3.25 kg-day target exposure of two silicon charge-coupled devices (CCDs), each with 24 megapixels and skipper readout, deployed in the DAMIC setup at SNOLAB. With reduction pixel readout noise factor 10 relative to previous detector, we investigate excess population low-energy events CCD bulk previously observed above expected backgrounds. address dominant systematic uncertainty analysis through depth fiducialization designed reject surface backgrounds on CCDs. The...
A bstract Oscura is a planned light-dark matter search experiment using Skipper-CCDs with total active mass of 10 kg. As part the detector development, collaboration plans to build Integration Test (OIT), an engineering test 10% mass. Here we discuss early science opportunities OIT for millicharged particles (mCPs) NuMI beam at Fermilab. mCPs would be produced low energies through photon-mediated processes from decays scalar, pseudoscalar, and vector mesons, or direct Drell-Yan productions....
Experiments aiming to directly detect dark matter through particle recoils can achieve energy thresholds of $\mathcal{O}(1\,\mathrm{eV})$. In this regime, ionization signals from small-angle Compton scatters environmental $\gamma$-rays constitute a significant background. Monte Carlo simulations used build background models have not been experimentally validated at these low energies. We report precision measurement scattering on silicon atomic shell electrons down 23$\,$eV. A skipper...
A 30-g xenon bubble chamber, operated at Northwestern University in June and November 2016, has for the first time observed simultaneous nucleation scintillation by nuclear recoils a superheated liquid. This chamber is instrumented with CCD camera near-IR imaging, solar-blind photomultiplier tube to detect 175-nm light, piezoelectric acoustic transducer ultrasonic emission from growing bubble. The of determined signal used correlate specific pulses bubble-nucleating events. We report on data...