A5107827060- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Pulsars and Gravitational Waves Research
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- High-pressure geophysics and materials
- Gamma-ray bursts and supernovae
- Geophysics and Sensor Technology
- Electron and X-Ray Spectroscopy Techniques
- Cultural and Historical Studies
- Catalysis and Oxidation Reactions
- Nuclear Physics and Applications
- Astrophysical Phenomena and Observations
- Consumer Perception and Purchasing Behavior
- X-ray Spectroscopy and Fluorescence Analysis
- Consumer Retail Behavior Studies
- Diverse Topics in Contemporary Research
- Advancements in Photolithography Techniques
- Machine Learning in Materials Science
- Atomic and Molecular Physics
- Geophysics and Gravity Measurements
- Radiation Therapy and Dosimetry
- Management, Economics, and Public Policy
Pusan National University
2025
University of Connecticut
2017-2024
Northwestern University
2022
Korea Research Institute of Standards and Science
2021
Kyungpook National University
2007-2017
Arizona State University
2012
Canisius College
2012
University of Genoa
2012
California State University, Dominguez Hills
2012
Argonne National Laboratory
2012
The atomic nucleus is composed of two different kinds fermions, protons and neutrons. If the neutrons did not interact, Pauli exclusion principle would force majority fermions (usually neutrons) to have a higher average momentum. Our high-energy electron scattering measurements using 12C, 27Al, 56Fe 208Pb targets show that, even in heavy neutron-rich nuclei, short-range interactions between form correlated high-momentum neutron-proton pairs. Thus, greater probability than momentum Fermi This...
New results on quasi-free η photoproduction the neutron and proton bound in a deuteron target are presented. The γn→ηn cross section reveals bump-like structure which is not seen proton. This may signal existence of relatively narrow (M∼1.68GeV, Γ⩽30MeV) baryon state.
Because of their long lifetimes, the ω and ϕ mesons are ideal candidates for study possible modifications in-medium meson-nucleon interaction through absorption inside nucleus. During E01-112 experiment at Thomas Jefferson National Accelerator Facility, were photoproduced from 2H, C, Ti, Fe, Pb targets. This Letter reports first measurement ratio nuclear transparencies e+e- channel. The ratios indicate larger widths compared with what have been reported in other reaction channels. meson is...
High-statistics measurements of differential cross sections and spin density matrix elements for the reaction $\ensuremath{\gamma}p\ensuremath{\rightarrow}\ensuremath{\phi}p$ have been made using CLAS detector at Jefferson Lab. We cover center-of-mass energies ($\sqrt{s}$) from 1.97 to 2.84 GeV, with an extensive coverage in $\ensuremath{\phi}$ production angle. The high statistics data sample it necessary carefully account interplay between natural lineshape effects resolution, that are...
Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton $\vec{e}\vec{p} \to e' p'\gamma$ are presented. The data were taken at Jefferson Lab using CLAS detector a longitudinally polarized ${}^{14}$NH$_3$ target. three measured in 165 4-dimensional kinematic bins, covering widest range ever explored simultaneously beam target-polarization observables valence quark region. dependences of obtained discussed compared to predictions models...
Exclusive $\pi^0$ electroproduction at a beam energy of 5.75 GeV has been measured with the Jefferson Lab CLAS spectrometer. Differential cross sections were more than 1800 kinematic values in $Q^2$, $x_B$, $t$, and $\phi_\pi$, $Q^2$ range from 1.0 to 4.6 GeV$^2$,\ $-t$ up 2 GeV$^2$, $x_B$ 0.1 0.58. Structure functions $\sigma_T +\epsilon \sigma_L, \sigma_{TT}$ $\sigma_{LT}$ extracted as $t$ for each 17 combinations $x_B$. The data compared directly two handbag-based calculations including...
We have measured the nuclear transparency of incoherent diffractive $A(e,e'\rho^0)$ process in $^{12}$C and $^{56}$Fe targets relative to $^2$H using a 5 GeV electron beam. The transparency, ratio produced $\rho^0$'s on nucleus deuterium, which is sensitive $\rho A$ interaction, was studied as function coherence length ($l_c$), lifetime hadronic fluctuation virtual photon, four-momentum transfer squared ($Q^2$). While for both showed no $l_c$ dependence, significant $Q^2$ dependence...
Differential cross sections of the exclusive process $ep\ensuremath{\rightarrow}{e}^{\ensuremath{'}}{\ensuremath{\pi}}^{+}n$ were measured with good precision in range photon virtuality ${Q}^{2}=1.8--4.5$ ${\mathrm{GeV}}^{2}$ and invariant mass ${\ensuremath{\pi}}^{+}n$ final state $W=1.6--2.0$ GeV using Continuous Electron Beam Accelerator Facility Large Acceptance Spectrometer. Data collected nearly complete coverage azimuthal polar angles $n{\ensuremath{\pi}}^{+}$ center-of-mass system....
We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at Thomas Jefferson National Accelerator Facility. A substantial $\sin \phi_h$ amplitude has been measured distribution cross section asymmetry as a function azimuthal angle $\phi_h$ produced pion. The dependence this on Bjorken $x$ and transverse...
The first study of quasi-free Compton scattering on the neutron in energy range $E_{\gamma}=0.75 - 1.5$ GeV is presented. data reveals a narrow peak at $W\sim 1.685$ GeV. This result, being considered conjunction with recent evidence for structure 1.68$GeV $\eta$ photoproduction neutron, suggests existence new nucleon resonance unusual properties: mass $M\sim 1.685$GeV, width $\Gamma \leq 30$MeV, and much stronger photoexcitation than proton.
We report the first measurement of photoproduction cross section $\phi$ meson in its neutral decay mode reaction $\gamma p \to p\phi(K_SK_L)$. The experiment was performed with a tagged photon beam energy $1.6 \le E_\gamma 3.6$ GeV incident on liquid hydrogen target CLAS spectrometer at Thomas Jefferson National Accelerator Facility. $p \phi$ final state is identified via reconstruction $K_S$ invariant mass two oppositely charged pions and by requiring missing particle K_S X$ to be $K_L$....
Background: The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations TPE corrections have significant model dependence, there limited direct experimental evidence for such corrections.Purpose: contributions depend on sign lepton charge in ${e}^{\ifmmode\pm\else\textpm\fi{}}p$ scattering, but luminosities secondary positron beams past...
We have measured the $^{3}\mathrm{He}(e,{e}^{\ensuremath{'}}pp)n$ reaction at an incident energy of 4.7 GeV over a wide kinematic range. identified spectator correlated $pp$ and $pn$ nucleon pairs by using cuts their relative total momentum distributions. This is first measurement ratio to as function pair ${p}_{\mathrm{tot}}$. For momenta between 0.3 $0.5\text{ }\text{ }\mathrm{GeV}/c$, very small low ${p}_{\mathrm{tot}}$ rises approximately 0.5 large shows dominance tensor central...
We report measurements of the exclusive electroproduction $K^+\Lambda$ and $K^+\Sigma^0$ final states from an unpolarized proton target using CLAS detector at Thomas Jefferson National Accelerator Facility. The separated structure functions $\sigma_U$, $\sigma_{LT}$, $\sigma_{TT}$, $\sigma_{LT'}$ were extracted $\Phi$-dependent differential cross sections acquired with a longitudinally polarized 5.499 GeV electron beam. data span broad range momentum transfers $Q^2$ 1.4 to 3.9 GeV$^2$,...
The exclusive electroproduction of $\pi^+$ above the resonance region was studied using $\rm{CEBAF}$ Large Acceptance Spectrometer ($\rm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off hydrogen target. large acceptance and good resolution $\rm{CLAS}$, together with high luminosity, allowed us to measure cross section for $\gamma^* p \to n \pi^+$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16<x_B<0.58$, 1.6 GeV$^2<$$Q^2$$<4.5$ GeV$^2$ 0.1 GeV$^2<$$-t$$<5.3$...
The first high-statistics cross sections for the reactions $\gamma p \to K^{*+} \Lambda$ and \Sigma^0$ were measured using CLAS detector at photon energies between threshold 3.9 GeV Thomas Jefferson National Accelerator Facility. Differential are presented over full range of center-of-mass angles, $\theta^{CM}_{K^{*+}}$, then fitted to Legendre polynomials extract total section. Results $K^{*+}\Lambda$ final state compared with two different calculations in an isobar a Regge model,...
The target and double spin asymmetries of the exclusive pseudoscalar channel e→p→→epπ0 were measured for first time in deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam proton at Jefferson Lab with CEBAF Large Acceptance Spectrometer (CLAS). data collected over large kinematic phase space divided into 110 four-dimensional bins Q2, xB, −t ϕ. values asymmetry moments clearly indicate substantial contribution to structure functions from transverse virtual photon...
We report the first extraction of pion-nucleon multipoles near production threshold for $n{\ensuremath{\pi}}^{+}$ channel at relatively high momentum transfer (${Q}^{2}$ up to 4.2 ${\mathrm{GeV}}^{2}$). The dominance $s$-wave transverse multipole (${E}_{0+}$), expected in this region, allowed us access generalized form factor ${G}_{1}$ within light-cone sum-rule (LCSR) framework as well axial ${G}_{A}$. data analyzed work were collected by nearly $4\ensuremath{\pi}$ CEBAF Large Acceptance...
The CLAS detector was used to obtain the first ever measurement of electromagnetic decay ${\ensuremath{\Sigma}}^{*+}(1385)$ from reaction $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{0}{\ensuremath{\Sigma}}^{*+}(1385)$. A real photon beam with a maximum energy 3.8 GeV incident on liquid-hydrogen target, resulting in photoproduction kaon and ${\ensuremath{\Sigma}}^{*}$ hyperon. Kinematic fitting separate channel background processes. algorithm exploited new method kinematically fit...
Main text A pilot study for the thickness measurement of HfO 2 films was performed by Surface Analysis Working Group (SAWG) Consultative Committee Amount Substance (CCQM). The aim this to ensure equivalency in capability national metrology institutes films. In study, thicknesses six with nominal from 1 nm 4 were measured X-ray Photoelectron Spectroscopy (XPS), Reflectometry(XRR), Fluorescence (XRF), Transmission Electron (TEM), Spectroscopic Ellipsometry (SE) and Rutherford Backscattering...
We have measured the differential cross section for $\ensuremath{\gamma}$$^{3}\mathrm{He}$$\ensuremath{\rightarrow}\ensuremath{\pi}{}^{+}t$ reaction. This reaction was studied using Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Real photons produced with Hall-B bremsstrahlung tagging system in energy range from 0.50 to 1.55 GeV were incident on a cryogenic liquid $^{3}\mathrm{He}$ target. The sections as function of photon-beam...
We have measured cross sections for the γ(3)He → pd reaction at photon energies of 0.4-1.4 GeV and a center-of-mass angle 90°. observe dimensional scaling above 0.7 this angle. This is first observation in photodisintegration nucleus heavier than deuteron.