C.A. Hardy
A5014006492- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Quantum, superfluid, helium dynamics
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Radioactivity and Radon Measurements
- Atmospheric Ozone and Climate
- Radiation Therapy and Dosimetry
- Cosmology and Gravitation Theories
- Pneumonia and Respiratory Infections
- Scientific Research and Discoveries
- Radioactive contamination and transfer
Stanford University
2021-2024
Institute of Microelectronics
2023
Chinese Academy of Sciences
2023
Kavli Institute for Particle Astrophysics and Cosmology
2021
SLAC National Accelerator Laboratory
2021
Queen's University
2019-2020
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,...
This paper introduces the neutrinoless double-beta decay (the rarest nuclear weak process) and describes status of research for this transition, both from point view theoretical physics in terms present future experimental scenarios. Implications phenomenon on crucial aspects particle are briefly discussed. The calculations matrix elements case mass mechanisms reviewed, a range these quantities is proposed most appealing candidates. After introducing general concepts—such as choice best...
Abstract The nEXO neutrinoless double beta (0 νββ ) decay experiment is designed to use a time projection chamber and 5000 kg of isotopically enriched liquid xenon search for the in 136 Xe. Progress detector design, paired with higher fidelity its simulation an advanced data analysis, based on one used final results EXO-200, produce sensitivity prediction that exceeds half-life 10 28 years. Specifically, improvements have been made understanding production scintillation photons charge as...
LUX-ZEPLIN is a dark matter detector expected to obtain world-leading sensitivity weakly-interacting massive particles interacting via nuclear recoils with $\ensuremath{\sim}7$-tonne xenon target mass. This paper presents projections several low-energy signals of the complementary electron recoil signal type: 1) an effective neutrino magnetic moment, and 2) millicharge, both for $pp$-chain solar neutrinos, 3) axion flux generated by Sun, 4) axionlike forming Galactic matter, 5) hidden...
Liquid xenon time projection chambers are promising detectors to search for neutrinoless double beta decay (0$\nu \beta \beta$), due their response uniformity, monolithic sensitive volume, scalability large target masses, and suitability extremely low background operations. The nEXO collaboration has designed a tonne-scale chamber that aims 0$\nu \beta$ of \ce{^{136}Xe} with projected half-life sensitivity $1.35\times 10^{28}$~yr. To reach this sensitivity, the design goal is $\leq$1\%...
The primary advantage of moderately superheated bubble chamber detectors is their simultaneous sensitivity to nuclear recoils from weakly interacting massive particle (WIMP) dark matter and insensitivity electron recoil backgrounds. A comprehensive analysis PICO gamma calibration data demonstrates for the first time that in ${\mathrm{C}}_{3}{\mathrm{F}}_{8}$ scale accordance with a new nucleation mechanism, rather than one driven by hot spike as previously supposed. Using this semiempirical...
Neutrinoless double beta decay is one of the most sensitive probes for new physics beyond Standard Model particle physics. One isotopes under investigation <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Xe</a:mi><a:mprescripts/><a:none/><a:mn>136</a:mn></a:mmultiscripts></a:math>, which would into <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mmultiscripts><b:mi>Ba</b:mi><b:mprescripts/><b:none/><b:mn>136</b:mn></b:mmultiscripts></b:math>. Detecting...
The search for neutrinoless double beta decay is the only practical way to test whether neutrinos are Majorana or Dirac particles. next generation of experiments aim probe effective neutrino mass down few 10 meV, as predicted by oscillation in case inverse hierarchy. According recent nuclear matrix calculations, rates per isotope varying within a factor when comparing them same theoretical model framework. sensitivity upcoming depend therefore primarily on available isotopes and experimental...
Silicon photomultipliers are regarded as a very promising technology for next-generation, cutting-edge detectors low-background experiments in particle physics. This work presents systematic reflectivity studies of Photomultipliers (SiPM) and other samples liquid xenon at vacuum ultraviolet (VUV) wavelengths. A dedicated setup the University Münster has been used that allows to acquire angle-resolved reflection measurements various immersed with 0.45° angular resolution. Four investigated...
Electron-neutrino charged-current interactions with xenon nuclei were modeled in the nEXO neutrinoless double-<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>β</a:mi></a:math> decay detector (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mo>∼</c:mo><c:mn>5</c:mn></c:math> metric ton, 90% <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...
Abstract We study a possible calibration technique for the nEXO experiment using 127 Xe electron capture source. is next-generation search neutrinoless double beta decay (0 νββ ) that will use 5-tonne, monolithic liquid xenon time projection chamber (TPC). The xenon, used both as source and detection medium, be enriched to 90% in 136 Xe. To optimize event reconstruction energy resolution, calibrations are needed map position- time-dependent detector response. 36.3 day half-life of its small...