C. J. Martoff
A5039097941- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- High-Energy Particle Collisions Research
- Quantum, superfluid, helium dynamics
- Muon and positron interactions and applications
- Superconducting and THz Device Technology
- Particle accelerators and beam dynamics
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Radiation Therapy and Dosimetry
- Advanced Chemical Physics Studies
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced NMR Techniques and Applications
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
Temple University
2015-2024
Temple College
1999-2024
Pacific Northwest National Laboratory
2022-2024
D. Mendeleyev University of Chemical Technology of Russia
2023
Jagiellonian University
2022
Institute of Physics
2022
Enrico Fermi Center for Study and Research
2022
Royal Holloway University of London
2021
University of California, Davis
2021
Princeton University
2015
We report the first results of DarkSide-50, a direct search for dark matter operating in underground Laboratori Nazionali del Gran Sasso (LNGS) and searching rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The detector is Liquid Argon Time Projection Chamber with (46.4+-0.7) kg active mass, operated inside 30 t organic liquid scintillator neutron veto, which turn installed at center 1 kt water Cherenkov veto residual flux cosmic rays. here null...
Liquid argon is a bright scintillator with potent particle identification properties, making it an attractive target for direct-detection dark matter searches. The DarkSide-50 search here reports the first WIMP results obtained using of low-radioactivity argon. detector, two-phase liquid time projection chamber, located at Laboratori Nazionali del Gran Sasso. underground shown to contain Ar-39 level reduced by factor (1.4 +- 0.2) x 10^3 relative atmospheric We report background-free null...
An application of intensity interferometry to relativistic heavy ion collisions is reported. The correlation between two like-charged pions used study the reactions $\mathrm{A}\mathrm{r}+\mathrm{K}\mathrm{C}\mathrm{l}\ensuremath{\rightarrow}{2\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}+X$ and $\mathrm{N}\mathrm{e}+\mathrm{N}\mathrm{a}\mathrm{F}\ensuremath{\rightarrow}{2\ensuremath{\pi}}^{\ensuremath{-}}+X$, both at an incident beam energy $1.8A$ GeV. Source sizes lifetimes are measured...
We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function applied electric field by exposing dual-phase time projection chamber (LAr-TPC) to low energy pulsed narrow band neutron beam produced at Notre Dame Institute for Structure Nuclear Astrophysics. Liquid counters were arranged detect identify neutrons scattered TPC select nuclei. report measurements yields nuclear recoils with energies from 10.3 57.3 keV median fields 0 $970\text{ }\text{...
Measurements of the forward-angle differential cross section for elastic electron-proton scattering were made in range momentum transfer from ${Q}^{2}=2.9 \mathrm{to} 31.3$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ using an electron beam at Stanford Linear Accelerator Center. The data span six orders magnitude section. Combinded statistical and systematic uncertainties measurements ranged 3.6% low ${Q}^{2}$ to 19% high ${Q}^{2}$. These have been used extract proton magnetic form...
We have performed absolute measurements of the differential cross section for elastic $e\ensuremath{-}p$ scattering in range momentum transfer from ${Q}^{2}=2.9 \mathrm{to} 31.3$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. Combined statistical and systematic uncertainties cross-section ranged 3% at low ${Q}^{2}$ to 19% high ${Q}^{2}$. These data been used extract proton magnetic form factor ${G}_{M}^{p}({Q}^{2})$. The results show a smooth decrease ${Q}^{4}{G}_{M}^{p}$ with above...
▪ Abstract We summarize residual background sources encountered in experiments conducted deep underground. Physical mechanisms of production and methods estimation for the dominant are considered, comparisons calculations with underground measurements discussed. Principal discussed include primary interactions cosmic rays, neutron by rays low energy backgrounds from neutrons, primordial anthropogenic radionuclides, secondary radioactivity spallation.
Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are great interest for developing an improved understanding star formation and evolution. Given expected neutrino fluxes known detection reactions, such require detectors capable collecting neutrino-electron scattering data exposures on order 1 ktonne yr, with good energy resolution extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) under development direct Dark...
Nuclear recoil events produced by neutron scatters form one of the most important classes background in WIMP direct detection experiments, as they may produce nuclear recoils that look exactly like interactions. In DarkSide-50, we both actively suppress and measure rate neutron-induced using our veto, composed a boron-loaded liquid scintillator detector within water Cherenkov detector. This paper is devoted to description veto system including structure, fundamentals event reconstruction...
Weakly interacting massive particles (WIMPs) are an attractive candidate for the dark matter thought to make up bulk of mass our universe. We explore here possibility using a low pressure negative ion time projection chamber search WIMPs. The innovation drifting ions, instead electrons, allows design detector with very high sensitivity and background rejection robust statistical signature WIMP interactions.
The deuteron elastic structure function $A({Q}^{2})$ has been extracted in the range $0.7\ensuremath{\le}{Q}^{2}\ensuremath{\le}6.0(\mathrm{GeV}/c{)}^{2}$ from cross section measurements of electron-deuteron scattering coincidence using Hall A Facility Jefferson Laboratory. data are compared to theoretical models, based on impulse approximation with inclusion meson-exchange currents, and predictions quark dimensional scaling perturbative quantum chromodynamics.
We have exposed a dual-phase liquid argon time projection chamber (LAr-TPC) to low energy pulsed narrow-band neutron beam, produced at the Notre Dame Institute for Structure and Nuclear Astrophysics, study scintillation light yield of recoiling nuclei. Liquid counters were arranged detect identify neutrons scattered in LAr-TPC select report observation significant dependence (up 32%) on drift field from nuclear recoils energies between 10.8 49.9 keV. The is stronger lower energies. Since it...
Abstract We describe a project that brings together researchers from atomic physics, nuclear physics and sub-atomic particle to develop high-precision laboratory-scale experiment able search for very weakly coupled sterile neutrinos in the mass range extending 5–10 keV/ c 2 several 100 . Observed neutrino flavor eigenstates are known be quantum mixtures of at least three sub-eV/ eigenstates. There is strong theoretical belief there may exist further higher levels, which, if range, might form...
We report measurements of cross sections for the reaction 1H(e,e′K+)Y, both Λ and Σ0 hyperon states, at an invariant mass W=1.84GeV four-momentum transfers 0.5<Q2<2(GeV/c)2. Data were taken three values virtual photon polarization ε, allowing decomposition into longitudinal transverse components. The data are a revised analysis prior work, whereas results have not been previously reported.Received 5 November 2002DOI:https://doi.org/10.1103/PhysRevC.67.055205©2003 American Physical Society
Doubly differential cross sections for the production of ${\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}$ near velocity incident beam pion laboratory angles from 0 to 20 degrees are presented. Beams $^{20}\mathrm{Ne}$ with $\frac{E}{A}=280, 380, \mathrm{and} 480$ MeV $^{40}\mathrm{Ar}$ $\frac{E}{A}=535$ on C, NaF, KCl, Cu, U targets were used. A sharp peak in spectrum a depression is observed at 0\ifmmode^\circ\else\textdegree\fi{} projectile velocity. The effect explained...
The ${}^{1}\mathrm{H}({e,e}^{\ensuremath{'}}{K}^{+})\ensuremath{\Lambda}$ reaction was studied as a function of the squared four-momentum transfer, ${Q}^{2}$, and virtual photon polarization, $\ensuremath{\varepsilon}$. For each four ${Q}^{2}$ settings, 0.52, 0.75, 1.00, 2.00 $(\mathrm{GeV}/c{)}^{2}$, longitudinal transverse cross sections were extracted in measurements at three polarizations. dependence ${\ensuremath{\sigma}}_{L}/{\ensuremath{\sigma}}_{T}$ ratio differs significantly from...
An alternate approach was used to study the reactions of muonic atoms and molecules in solid layers hydrogen isotopes. Muons stopped a protium layer with small admixture tritium producing \ensuremath{\mu}p atoms. Muon transfer from proton triton generated \ensuremath{\mu}t atoms, which were emitted into deuterium layer. Subsequent epithermal dt\ensuremath{\mu} molecular formation followed by dt fusion gave prompt signal for emission. Fusion time spectra at various concentrations measured...
Dark matter (DM) detectors with directional sensitivity have the potential of yielding an unambiguous positive observation WIMPs as well discriminating between galactic DM halo models. In this paper, we introduce motivation for detectors, discuss experimental techniques that make detection possible, and review status effort in field.