A5075266771- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Particle Accelerators and Free-Electron Lasers
- Nuclear reactor physics and engineering
- Dark Matter and Cosmic Phenomena
- Cold Fusion and Nuclear Reactions
- Crystallization and Solubility Studies
- Superconducting Materials and Applications
- X-ray Diffraction in Crystallography
- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Computational Physics and Python Applications
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Quantum chaos and dynamical systems
- Mass Spectrometry Techniques and Applications
- Fusion materials and technologies
- Twentieth Century Scientific Developments
- Scientific Research and Discoveries
Los Alamos National Laboratory
2011-2023
University of Maryland, College Park
1997-2019
Old Dominion University
2000-2018
Dominion (United States)
2004
Karlsruhe University of Education
1997
Los Alamos Medical Center
1997
Paul Scherrer Institute
1997
New Mexico State University
1991-1997
University of Basel
1987-1997
University of Zagreb
1997
Measurements are reported of the proton and deuteron spin structure functions ${g}_{1}^{p}$ ${g}_{1}^{d}$ at beam energies 29.1, 16.2, 9.7 GeV, ${g}_{2}^{p}$ ${g}_{2}^{d}$ a energy 29.1 GeV. The integrals ${\ensuremath{\Gamma}}_{p}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{p}{(x,Q}^{2})dx$ ${\ensuremath{\Gamma}}_{d}={\ensuremath{\int}}_{0}^{1}{g}_{1}^{d}{(x,Q}^{2})dx$ were evaluated fixed ${Q}^{2}=3(\mathrm{GeV}{/c)}^{2}$ using full data set to yield...
A precise measurement of the atomic-mass dependence dimuon production induced by 800-GeV protons is reported. Over 450 000 muon pairs with mass M\ensuremath{\ge}4 GeV were recorded from targets $^{2}\mathrm{H}$, C, Ca, Fe, and W. The ratio yield per nucleon for nuclei versus R=${\mathit{Y}}_{\mathit{A}}$/${\mathit{Y}}_{2\mathit{H}}$, sensitive to modifications antiquark sea in nuclei. No nuclear this observed over range target-quark momentum fraction 0.1${\mathit{x}}_{\mathit{t}}$0.3. For...
We have measured the ratio $\frac{{g}_{1}^{p}}{{F}_{1}^{p}}$ over range $0.029<x<0.8$ and $1.3<{Q}^{2}<10$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ using deep-inelastic scattering of polarized electrons from ammonia. An evaluation integral $\ensuremath{\int}{0}^{1}{g}_{1}^{p}(x, {Q}^{2})\mathrm{dx}$ at fixed ${Q}^{2}=3$ yields 0.127\ifmmode\pm\else\textpm\fi{}0.004(stat)\ifmmode\pm\else\textpm\fi{}0.010(syst), in agreement with previous experiments, but well below Ellis-Jaffe sum...
Separated longitudinal and transverse structure functions for the reaction 1H(e,e(')pi(+))n were measured in momentum transfer region Q2 = 0.6--1.6 (GeV/c)(2) at a value of invariant mass W 1.95 GeV. New values pion charge form factor extracted from cross section by using recently developed Regge model. The results indicate that this is larger than previously assumed consistent with monopole parametrization fitted to very low elastic data.
The charged pion form factor, ${F}_{\ensuremath{\pi}}({Q}^{2})$, is an important quantity that can be used to advance our knowledge of hadronic structure. However, the extraction ${F}_{\ensuremath{\pi}}$ from data requires a model ${}^{1}\mathrm{H}(e,{e}^{'}{\ensuremath{\pi}}^{+})n$ reaction and thus inherently dependent. Therefore, detailed description factor electroproduction obtained recently at Jefferson Lab presented, with particular focus given dominant uncertainties in this procedure....
The yield of J/\ensuremath{\psi} and \ensuremath{\psi}' vector-meson states has been measured for 800-GeV protons incident on deuterium, carbon, calcium, iron, tungsten targets. A depletion the per nucleon from heavy nuclei is observed both production. This exhibits a strong dependence ${\mathit{x}}_{\mathit{F}}$ ${\mathit{p}}_{\mathit{t}}$. Within experimental errors same \ensuremath{\psi}'.
We report on a high-statistics measurement of the deuteron spin structure function ${g}_{1}^{d}$ at beam energy 29 GeV in kinematic range $0.029<x<0.8$ and $1<{Q}^{2}<10$ (GeV $/c$${)}^{2}$. The integral ${\ensuremath{\gamma}}_{1}^{d}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{\int}{1}^{}{g}_{1}^{d}\mathrm{dx}$ evaluated fixed ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3$ $/c$${)}^{2}$ gives...
The data analysis for the reaction H(e,e' pi^+)n, which was used to determine values charged pion form factor Fpi of Q^2=0.6-1.6 GeV^2, has been repeated with careful inspection all steps and special attention systematic uncertainties. Also method extract from measured longitudinal cross section critically reconsidered. Final separated transverse sections extracted are presented.
We have measured the neutron electric form factor Gen via 3He→(e→,e′n)pp at Q2=0.67(GeV/c)2 using 3-spectrometer facility of A1 Collaboration Mainz Microtron and a dedicated detector. High pressure polarized 3He→ gas was used as target neutrons. is determined from ratio asymmetries A⊥/A∥ in quasifree kinematics with spin perpendicular parallel to momentum transfer. find Gen=0.052±0.011±0.005.Received 30 April 1999DOI:https://doi.org/10.1103/PhysRevLett.83.4257©1999 American Physical Society
The electric form factor of the neutron was determined from measurements $\stackrel{\ensuremath{\rightarrow}}{d}(\stackrel{\ensuremath{\rightarrow}}{e},{e}^{\ensuremath{'}}n)p$ reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia ($^{15}\mathrm{N}\mathrm{D}_{3}$) target in which deuteron polarization perpendicular to momentum transfer. detected magnetic spectrometer coincidence with neutrons large solid angle detector. We find...
We have measured proton and deuteron virtual photon-nucleon asymmetries ${A}_{2}^{p}$ ${A}_{2}^{d}$ structure functions ${g}_{2}^{p}$ ${g}_{2}^{d}$ over the range $0.03<x<0.8$ $1.3<{Q}^{2}<10(\mathrm{GeV}/c{)}^{2}$ by inelastically scattering polarized electrons off ammonia targets. Results for ${A}_{2}$ are significantly smaller than positivity limit $\sqrt{R}$ both Within experimental precision ${g}_{2}$ data well described twist-2 contribution, ${g}_{2}^{\mathrm{WW}}$. Twist-3 matrix...
The yields of the 1S and sum 2S 3S \ensuremath{\Upsilon} resonances have been measured for 800-GeV protons incident on targets $^{2}\mathrm{H}$, C, Ca, Fe, W. A significant nuclear dependence is seen in yield per nucleon which, within errors, same \ensuremath{\Upsilon}(1S) \ensuremath{\Upsilon}(2S+3D) states. large decrease relative from heavy nuclei found range ${\mathit{x}}_{\mathit{F}}$0. Significant also observed ${\mathit{p}}_{\mathit{t}}$ distribution. Differential cross sections...
Cross sections for the reaction ${}^{1}\mathrm{H}(e,{e}^{'}{\ensuremath{\pi}}^{+})n$ were measured in Hall C at Thomas Jefferson National Accelerator Facility (JLab) using high-intensity Continuous Electron Beam (CEBAF) to determine charged pion form factor. Data taken central four-momentum transfers ranging from ${Q}^{2}=0.60$ 2.45 ${\mathrm{GeV}}^{2}$ an invariant mass of virtual photon-nucleon system $W=1.95$ and 2.22 GeV. The cross separated into four structure functions...
The charge form factor of the neutron has been determined from asymmetries measured in quasi--elastic pol.3He(pol e,e'n) at a momentum transfer 0.67(GeV/c)^2. In addition, target analyzing power, A_y^o, to study effects final state interactions and meson exchange currents.
We present results from the comparison of high-resolution three-dimensional (3D) simulations with data implosions inertial confinement fusion capsules separated reactants performed on OMEGA laser facility. Each capsule, referred to as a “CD Mixcap,” is filled tritium and has polystyrene (CH) shell deuterated (CD) layer whose burial depth varied. In these implosions, reactions between deuterium ions can occur only in presence atomic mix gas fill material. The feature accurate models for all...
The ratio g1F1 has been measured over the range 0.03 < x 0.6 and 0.3 Q2 10 (GeV/c)2 using deep-inelastic scattering of polarized electrons from protons deuterons. We find to be consistent with no Q2-dependence at fixed in region > 1 (GeV/c)2. A trend is observed for decrease lower Q2. Fits world data without a possible are agreement Bjorken sum rule, but Δq substantially less than quark-parton model expectation.
The first measurements of the differential cross section for d(gamma,p)n reaction up to 4.0 GeV were performed at Continuous Electron Beam Accelerator Facility (CEBAF) Jefferson Lab. We report sections proton center-of-mass angles 36, 52, 69 and 89 degrees. These results are in reasonable agreement with previous lower energy. degree data show constituent-counting-rule behavior photon 36 52 disagree counting rule behavior. quantum chromodynamics (QCD) model nuclear reactions involving reduced...
We report the results from a systematic study of quasielastic $(e,{e}^{\ensuremath{'}}p)$ reaction on $^{12}\mathrm{C},\phantom{\rule{0.5em}{0ex}}^{56}\mathrm{Fe}$, and $^{197}\mathrm{Au}$ performed at Jefferson Lab. have measured nuclear transparency extracted spectral functions (corrected for radiation) over ${Q}^{2}$ range $0.64--3.25\phantom{\rule{0.5em}{0ex}}{(\text{GeV}∕c)}^{2}$ all three nuclei. In addition, we separated longitudinal transverse 0.64...
The ( ${e,e}^{\ensuremath{'}}p$) reaction was studied on targets of C, Fe, and Au at momentum transfers squared ${Q}^{2}$ 0.6, 1.3, 1.8, $3.3{\mathrm{GeV}}^{2}$ in a region kinematics dominated by quasifree electron-proton scattering. Missing energy missing distributions are reasonably well described plane wave impulse approximation calculations with $A$ dependent corrections that measure the attenuation final state protons.
The ratio of the proton's electric to magnetic form factor, ${G}_{E}/{G}_{M}$, can be extracted in elastic electron-proton scattering by measuring cross sections, beam-target asymmetry, or recoil polarization. Separate determinations ${G}_{E}/{G}_{M}$ sections and polarization observables disagree for ${Q}^{2}>1$ (GeV/$c){}^{2}$. Measurement a third technique might uncover an unknown systematic error either previous measurements. asymmetry has been measured at ${Q}^{2}$ = 1.51...
We have measured the proton and deuteron spin structure functions g_1^p g_1^d in region of nucleon resonances for W^2 < 5 GeV^2 $Q^2\simeq 0.5$ 1.2$ by inelastically scattering 9.7 GeV polarized electrons off $^{15}NH_3$ $^{15}ND_3$ targets. observe significant resonance region. used present results, together with deep-inelastic data at higher W^2, to extract $\Gamma(Q^2)\equiv\int_0^1 g_1(x,Q^2) dx$. This is first information on low-Q^2 evolution Gamma toward Gerasimov-Drell-Hearn limit Q^2 = 0.