A5064833119- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Physics of Superconductivity and Magnetism
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Magnetic properties of thin films
- Quantum, superfluid, helium dynamics
- Cosmology and Gravitation Theories
- Copper Interconnects and Reliability
- Fluid Dynamics and Thin Films
- Nuclear physics research studies
- Particle accelerators and beam dynamics
- Computational Physics and Python Applications
- Gamma-ray bursts and supernovae
- Adhesion, Friction, and Surface Interactions
- Magnetic Bearings and Levitation Dynamics
- Spectroscopy and Laser Applications
- Laser Design and Applications
- Atmospheric Ozone and Climate
- Advanced X-ray Imaging Techniques
- Advanced Wireless Communication Techniques
- Muon and positron interactions and applications
University of Massachusetts Amherst
2018-2023
University of California, Santa Cruz
2022
University of Illinois Urbana-Champaign
2013-2021
McGill University
2021
Stony Brook University
2015-2020
SLAC National Accelerator Laboratory
2017
University of Zurich
2009-2015
Max Planck Institute for Physics
2015
Access
2001-2003
We report results from a blind analysis of the final data taken with Cryogenic Dark Matter Search experiment (CDMS II) at Soudan Underground Laboratory, Minnesota, USA. A total raw exposure 612 kg-days was analyzed for this work. observed two events in signal region; based on our background estimate, probability observing or more is 23%. These set an upper limit Weakly Interacting Massive Particle (WIMP)-nucleon elastic-scattering spin-independent cross-section 7.0x10^{-44} cm^2 WIMP mass 70...
Neutrinoless double beta decay is a process that violates lepton number conservation. It predicted to occur in extensions of the standard model particle physics. This Letter reports results from phase I Germanium Detector Array (GERDA) experiment at Gran Sasso Laboratory (Italy) searching for neutrinoless isotope $^{76}\mathrm{Ge}$. Data considered present analysis have been collected between November 2011 and May 2013 with total exposure 21.6 kg yr. A blind performed. The background index...
We report results from a reanalysis of data the Cryogenic Dark Matter Search (CDMS II) experiment at Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with lowered, 2 keV recoil-energy threshold, to give increased sensitivity interactions weakly interacting massive particles (WIMPs) masses below ∼10 GeV/c(2). This analysis provides stronger constraints than previous CDMS II for WIMP 9 GeV/c(2) excludes parameter...
We report first results from the Cryogenic Dark Matter Search (CDMS II) experiment running with its full complement of 30 cryogenic particle detectors at Soudan Underground Laboratory. This is based on analysis data acquired between October 2006 and July 2007 15 Ge (3.75 kg), giving an effective exposure 121.3 kg-d (averaged over recoil energies 10--100 keV, weighted for a weakly interacting massive (WIMP) mass 60 \gev). A blind analysis, incorporating improved techniques event...
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 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...
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...
We report on the first axion search results from Cryogenic Dark Matter Search (CDMS) experiment at Soudan Underground Laboratory. An energy threshold of 2 keV for electron-recoil events allows a possible solar conversion into photons or local galactic electrons in germanium crystal detectors. The sets an upper limit Primakov coupling ${g}_{a\ensuremath{\gamma}\ensuremath{\gamma}}$ $2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$...
The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta decay 76Ge. signature signal a monoenergetic peak 2039 keV, Q-value decay, Q_bb. To avoid bias in search, present analysis does not consider all those events, that fall 40 keV wide region centered around main parameters needed are described. A background model was developed to describe observed energy spectrum. contains several contributions,...
The GERDA experiment located at the LNGS searches for neutrinoless double beta (0\nu\beta\beta) decay of ^{76}Ge using germanium diodes as source and detector. In Phase I eight semi-coaxial five BEGe type detectors have been deployed. latter is used in this field research first time. All are made from material with enriched fraction. experimental sensitivity can be improved by analyzing pulse shape detector signals aim to reject background events. This paper documents algorithms developed...
We report limits on annual modulation of the low-energy event rate from Cryogenic Dark Matter Search (CDMS II) experiment at Soudan Underground Laboratory. Such a could be produced by interactions Weakly Interacting Massive Particles (WIMPs) with masses ~10 GeV/c^2. find no evidence for in veto-anticoincident single-detector consistent nuclear recoils, and constrain magnitude any to <0.06 [keVnr kg day]^-1 5-11.9 keVnr energy range 99% confidence level. These results disfavor an...
The primary goal of the GERmanium Detector Array (Gerda) experiment at Laboratori Nazionali del Gran Sasso INFN is search for neutrinoless double beta decay 76 Ge.High-purity germanium detectors made from material enriched in Ge are operated directly immersed liquid argon, allowing a substantial reduction background with respect to predecessor experiments.The first 5.04 kg•yr data collected Phase I have been analyzed measure half-life neutrinoaccompanied Ge.The observed spectrum energy range...
A search for Lorentz- and $CPT$-violating signals in the double beta decay spectrum of $^{136}\mathrm{Xe}$ has been performed using an exposure $100\text{ }\text{ }\mathrm{kg}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{yr}$ with EXO-200 detector. No significant evidence spectral modification due to isotropic Lorentz-violation was found, a two-sided limit $\ensuremath{-}2.65\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}\text{...
We apply deep neural networks (DNN) to data from the EXO-200 experiment. In studied cases, DNN is able reconstruct relevant parameters—total energy and position—directly raw digitized waveforms, with minimal exceptions. For first time, developed algorithms are evaluated on real detector calibration data. The accuracy of reconstruction either reaches or exceeds what was achieved by conventional approaches over course Most existing event classification in particle physics trained Monte Carlo...
EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless double-beta decay of $^{136}$Xe. Here we report on various Majoron-emitting modes based 100 kg$\cdot$yr exposure A lower limit $T^{^{136}Xe}_{1/2} >1.2 \cdot 10^{24}$ yr at 90% C.L. the half-life spectral index = 1 Majoron was obtained, corresponding constraint Majoron-neutrino coupling constant $|< g^{M}_{ee} >|<$ (0.8-1.7)$\cdot$10$^{-5}$.
Alpha decays in the EXO-200 detector are used to measure fraction of charged $^{218}\text{Po}$ and $^{214}\text{Bi}$ daughters created from $\ensuremath{\alpha}$ $\ensuremath{\beta}$ decays, respectively. $^{222}\text{Rn} \ensuremath{\alpha}$ liquid xenon (LXe) found produce $^{218}\text{Po}^{+}$ ions $50.3\ifmmode\pm\else\textpm\fi{}3.0%$ time, while remainder atoms neutral. The $^{214}\text{Bi}^{+}$ $^{214}\text{Pb} \ensuremath{\beta}$ LXe is be $76.4\ifmmode\pm\else\textpm\fi{}5.7%$,...
The EXO-200 Collaboration is searching for neutrinoless double $\ensuremath{\beta}$ decay using a liquid xenon (LXe) time projection chamber. This measurement relies on modeling the transport of charge deposits produced by interactions in LXe to allow discrimination between signal and background events. Here we present measurements transverse diffusion constant drift velocity electrons at fields 20 V/cm 615 data. At operating field 380 measures...
The search for neutrinoless double-beta decay (0νββ) requires extremely low background and a good understanding of their sources influence on the rate in region parameter space relevant to 0νββ signal. We report studies various β γ backgrounds liquid-xenon-based EXO-2000νββ experiment. With this work we try better understand location strength specific compare conclusions radioassay results taken before during detector construction. Finally, discuss implications these EXO-200 as well...
Progress on a method of barium tagging for the nEXO double beta decay experiment is reported. Absorption and emission spectra deposits atoms ions in solid xenon matrices are presented. Excitation prominent lines, temperature dependence, bleaching fluorescence reveal existence different matrix sites. A regular series sharp lines observed ${\mathrm{Ba}}^{+}$ identified with some type hydride molecule. Lower limits quantum efficiency principal Ba transition Under current conditions, an image...
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...
As neutrinoless double-beta decay experiments become more sensitive and intrinsic radioactivity in detector materials is reduced, previously minor contributions to the background must be understood eliminated. With this mind, cosmogenic backgrounds have been studied with EXO-200 experiment. Using TPC, muon flux (through a flat horizontal surface) underground at Waste Isolation Pilot Plant (WIPP) has measured {\Phi} = 4.07 $\pm$ 0.14 (sys) 0.03 (stat) $\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$,...