Donal B. Day
A5056167936- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
- Photocathodes and Microchannel Plates
- Electron and X-Ray Spectroscopy Techniques
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Atomic and Molecular Physics
- Neutrino Physics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Chemical Physics Studies
- Gyrotron and Vacuum Electronics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Radiation Detection and Scintillator Technologies
- Magnetic confinement fusion research
- Computational Physics and Python Applications
- Muon and positron interactions and applications
University of Virginia
2014-2024
Thomas Jefferson National Accelerator Facility
2017-2018
Technical University of Darmstadt
2009
Friedrich-Alexander-Universität Erlangen-Nürnberg
2009
European Organization for Nuclear Research
1996
U.S. National Science Foundation
1993-1995
Stanford Synchrotron Radiation Lightsource
1995
SLAC National Accelerator Laboratory
1995
University of Trieste
1994
Uppsala University
1994
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...
Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing strong interaction dynamics nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements factor ratio using recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending range Q2 which G(E)(p) is accurately determined by more than 50%,...
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...
Experimental values of $^{3}\mathrm{He}$ ($^{4}\mathrm{He}$) elastic structure functions up to momentum transfer ${q}^{2}=4.0 (2.4)$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ are presented. They compared calculations using three- and four-body wave asymptotic models.
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...
This paper presents a review on the field of inclusive quasielastic electron-nucleus scattering. It discusses approach used to measure data and includes compilation available in numerical form. The theoretical approaches interpret are presented. A number results obtained from comparison between experiment calculation then reviewed. analogies to, differences from, other fields physics exploiting scattering composite systems pointed out.
We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The were made 28 distinct kinematic settings covering a range momentum transfer $0.4<{Q}^{2}<5.5\phantom{\rule{0.3em}{0ex}}{(\mathrm{GeV}∕c)}^{2}$. These represent significant contribution to world's data set ${Q}^{2}$ range, where large discrepancy currently exists between ratio electric magnetic proton form factors extracted from previous and that recently...
Following a major shortage of 99Mo in the 2009–2010 period, concern grew that aging reactor production facilities needed to be replaced. Most producers were using highly enriched 235U (HEU) as target material. The Organisation for Economic Co-...Read More
Inelastic electron scattering at large momentum transfer but small energy loss is used to investigate the high-momentum components in $^{3}\mathrm{He}$. The data also show a striking scaling dependence variable $y=\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}\ifmmode\cdot\else\textperiodcentered\fi{}\frac{\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}}{q}$.
New Jefferson Lab data are presented on the nuclear dependence of inclusive cross section from $^{2}\mathrm{H}$, $^{3}\mathrm{He}$, $^{4}\mathrm{He}$, $^{9}\mathrm{Be}$ and $^{12}\mathrm{C}$ for $0.3<x<0.9$, ${Q}^{2}\ensuremath{\approx}3--6\text{ }\text{ }{\mathrm{GeV}}^{2}$. These represent first measurement EMC effect $^{3}\mathrm{He}$ at large $x$ a significant improvement $^{4}\mathrm{He}$. The do not support previous $A$-dependent or density-dependent fits to suggest that quark...
Inelastic-electron-scattering cross sections for $^{56}\mathrm{Fe}$ have been measured in the continuum region. The longitudinal and transverse inelastic response functions determined vector momentum transfers, $q$, from 210-410 MeV/c energy losses $0<\ensuremath{\omega}<~220$ MeV.
We argue that the ratio of cross sections quasielastic electron scattering for heavy and light nuclei at x>1 ${\mathit{Q}}^{2}$>1 (GeV/c${)}^{2}$ should exhibit simple scaling relations which are ultimately expressed through light-cone nucleon distributions in nuclei. extract these section ratios from existing data a practically model independent way. The results found to be reasonable agreement with our x-scaling region 2>x\ensuremath{\ge}1.4 where contribution two-nucleon...
We present new measurements of electron scattering from high-momentum nucleons in nuclei. These data allow an improved determination the strength two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, first time, be examined. The also include kinematic region three-nucleon are expected to dominate.
This paper gives the results of a study single-pion production by weak charged current utilizing wide-band muon-type-neutrino beam at Argonne Zero Gradient Synchrotron. The data were obtained from hydrogen and deuterium fillings 12-ft bubble chamber. methods event selection separation background are given as details corrections systematic effects in sample. energy-dependent cross sections differential distributions presented for three reactions...
Data on inclusive electron scattering from $^{3}\mathrm{He}$ over a large range of momentum transfer (2-7 ${\mathrm{fm}}^{\ensuremath{-}1}$) are presented and compared with one-nucleon knockout calculation based Faddeev spectral function.
We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with or neutron recoiling almost back missing momentum, leaving residual A=2 system low excitation energy. These data were used identify two-nucleon short-range correlated pairs deduce their isospin structure as function momentum region where nucleon-nucleon force is expected...
New measurements are reported on the deuteron spin structure function g_1^d. These results were obtained from deep inelastic scattering of 48.3 GeV electrons polarized deuterons in kinematic range 0.01 < x 0.9 and 1 Q^2 40 (GeV/c)^2. first high dose electron data using lithium deuteride (6Li2H) as target material. Extrapolations performed to obtain moments g_1^d, including Gamma_1^d, net quark polarization Delta Sigma.
We report the first measurement using a solid polarized target of neutron electric form factor G(n)(E) via d-->(e-->,e(')n)p. was determined from beam-target asymmetry in scattering longitudinally electrons deuterated ammonia ( 15ND3). The performed Hall C at Thomas Jefferson National Accelerator Facility quasifree kinematics with polarization perpendicular to momentum transfer. were detected magnetic spectrometer coincidence neutrons large angle segmented detector. find =...
We have measured the spin structure functions g2p and g2d virtual photon asymmetries A2p A2d over kinematic range 0.02⩽x⩽0.8 0.7⩽Q2⩽20GeV2 by scattering 29.1 32.3 GeV longitudinally polarized electrons from transversely NH3 6LiD targets. Our g2 approximately follows twist-2 Wandzura–Wilczek calculation. The twist-3 reduced matrix elements d2p d2n are less than two standard deviations zero. data inconsistent with Burkhardt–Cottingham sum rule if there is no pathological behavior as x→0....
We report new measurements of the ratio electric form factor to magnetic neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties 7.6% 8.4% two higher points, which points have never been achieved in polarization measurements.
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...