A5052422825- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Atmospheric Ozone and Climate
- Photocathodes and Microchannel Plates
- Cellular Automata and Applications
- Quantum, superfluid, helium dynamics
- Image and Signal Denoising Methods
- Generative Adversarial Networks and Image Synthesis
- Nuclear physics research studies
- Mathematical Dynamics and Fractals
University of California, San Diego
2024
Drexel University
2019-2023
SLAC National Accelerator Laboratory
2021
Lawrence Livermore National Laboratory
2020
Triangle Universities Nuclear Laboratory
2019
Duke University
2019
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...
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...
Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure absolute scintillation ionization yields generated by $\ensuremath{\gamma}$ interactions from $^{228}\mathrm{Th}$ (2615 keV), $^{226}\mathrm{Ra}$ (1764 $^{60}\mathrm{Co}$ (1332 keV 1173 keV) calibration sources, over range electric fields. The $W$ value that defines recombination-independent energy scale measured be...
We present a search for electron-recoil signatures from the charged-current absorption of fermionic dark matter using EXO-200 detector. report an average background rate $6.8\ifmmode\times\else\texttimes\fi{}{10}^{4}\text{ }\text{ }\mathrm{cts}\text{ }{\mathrm{kg}}^{\ensuremath{-}1}\text{ }{\mathrm{yr}}^{\ensuremath{-}1}\text{ }{\mathrm{keV}}^{\ensuremath{-}1}$ above 4 MeV and find no statistically significant excess over our projection. Using total $^{136}\mathrm{Xe}$ exposure 234.1 kg yr,...
A search for Majoron-emitting modes of the neutrinoless double-beta decay $^{136}$Xe is performed with full EXO-200 dataset. This dataset consists a total exposure 234.1 kg$\cdot$yr, and includes data detector upgrades that have improved energy threshold relative to previous searches. lower limit T$_{1/2}^{\rm{^{136}Xe}}>$4.3$\cdot$10$^{24}$ yr at 90\% C.L. on half-life spectral index $n=1$ Majoron was obtained, factor 3.6 more stringent than from EXO-200, corresponding constraint...
Understanding reflective properties of materials and photodetection efficiency (PDE) photodetectors is important for optimizing energy resolution sensitivity the next generation neutrinoless double beta decay, direct detection dark matter, neutrino oscillation experiments that will use noble liquid gases, such as nEXO, DARWIN, DarkSide-20k, DUNE . Little information currently available about reflectivity PDE in because measurements are difficult to conduct a cryogenic environment at short...
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\%...
Characterization of the vacuum ultraviolet (VUV) reflectance silicon photomultipliers (SiPMs) is important for large-scale SiPM-based photodetector systems. We report angular dependence specular in a SiPMs manufactured by Fondazionc Bruno Kessler (FBK) and Hamamatsu Photonics K.K. (HPK) over wavelengths ranging from 120 nm to 280 nm. Refractive index extinction coefficient thin silicon-dioxide film deposited on surface FBK are derived data wafer with same oxide as SiPMs. The diffuse also...
The EXO-200 experiment searched for neutrinoless double-beta decay of $^{136}$Xe with a single-phase liquid xenon detector. It used an active mass 110 kg 80.6%-enriched in ultra-low background time projection chamber ionization and scintillation detection readout. This paper describes the design performance various support systems necessary detector operation, including cryogenics, handling, controls. Novel features system were driven by need to protect thin-walled containing xenon, achieve...
Generative Adversarial Networks trained on samples of simulated or actual events have been proposed as a way generating large datasets at reduced computational cost. In this work, novel approach to perform the simulation photodetector signals from time projection chamber EXO-200 experiment is demonstrated. The method based Wasserstein Network - deep learning technique allowing for implicit non-parametric estimation population distribution given set objects. Our network real calibration data...
nEXO is a proposed experiment to search for the neutrino-less double beta decay (0νββ) of 136Xe in tonne-scale liquid xenon time projection chamber (TPC) . The TPC will be equipped with charge collection tiles form anode. In this work, reconstruction performance anode design studied dedicated simulation package. A multi-variate method and deep neural network are developed distinguish simulated 0νββ signals from backgrounds arising trace levels natural radioactivity detector materials. These...
We report on a comparison between the theoretically predicted and experimentally measured spectra of first-forbidden nonunique β-decay transition 137Xe(7/2−)→137Cs(7/2+). The experimental data were acquired by EXO-200 experiment during deployment an AmBe neutron source. ultralow background environment EXO-200, together with dedicated source analysis procedures, allowed for collection pure sample decays, estimated signal to ratio more than 99 1 in energy range from 1075 4175 keV. In addition...
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...
Abstract A new search for two-neutrino double-beta (2 νββ ) decay of 136 Xe to the excited state Ba is performed with full EXO-200 dataset. deep learning-based convolutional neural network used discriminate signal from background events. Signal detection efficiency increased relative previous searches by more than a factor two. With addition Phase II dataset taken an upgraded detector, median 90% confidence level half-life sensitivity 2 yr using total exposure 234.1 kg yr. No statistically...
Image denoising is a popular technique that used to remove noise incurred due hardware faults or carefully crafted by an attacker. Autoencoders are some of the most denoisers. Their ability learn distribution's latent space helps them achieve this property, and they generally good at it. However, known fumble in white-box threat model where attacker knows everything about victim classifier its denoiser network - including architecture hyperparameters. We show problem stems from autoencoder's...
A new search for two-neutrino double-beta ($2\nu\beta\beta$) decay of $^{136}\rm Xe$ to the $0^+_1$ excited state Ba$ is performed with full EXO-200 dataset. deep learning-based convolutional neural network used discriminate signal from background events. Signal detection efficiency increased relative previous searches by more than a factor two. With addition Phase II dataset taken an upgraded detector, median 90$\%$ confidence level half-life sensitivity $2\nu\beta\beta$ $2.9 \times...
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...