A5047651355- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Muon and positron interactions and applications
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- Nuclear Physics and Applications
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Gyrotron and Vacuum Electronics Research
- Quantum, superfluid, helium dynamics
- Silicon Carbide Semiconductor Technologies
- Magnetic confinement fusion research
- Medical Imaging Techniques and Applications
- Advanced X-ray Imaging Techniques
- Advanced Surface Polishing Techniques
- Physics of Superconductivity and Magnetism
Thomas Jefferson National Accelerator Facility
2015-2024
Autonomous University of Sinaloa
2023
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2023
Oak Ridge National Laboratory
2023
Universidad de Guanajuato
2023
Brookhaven National Laboratory
2016
SLAC National Accelerator Laboratory
1995-2015
Old Dominion University
2014-2015
Clermont Université
2009-2012
Centre National de la Recherche Scientifique
1995-2012
The ratio of the proton's elastic electromagnetic form factors, G(E(p))/G(M(p)), was obtained by measuring P(t) and P(l), transverse longitudinal recoil proton polarization, respectively. For e-->p-->ep-->, G(E(p))/G(M(p)) is proportional to P(t)/P(l). Simultaneous measurement P(l) in a polarimeter provides good control systematic uncertainty. results for show decrease as Q2 increases from 0.5 3.5 GeV2, indicating first time definite difference spatial distribution charge magnetization...
The spin structure function of the neutron gn1 has been determined over range 0.03<x<0.6 at an average Q2 2 (GeV/c)2 by measuring asymmetry in deep inelastic scattering polarized electrons from a 3He target energies between 19 and 26 GeV. integral is found to be F10gn1(x)dx=-0.022±0.011. Earlier reported proton results together with Bjorken sum rule predict F10gn1(x)dx=-0.059±0.019.Received 1 April 1993DOI:https://doi.org/10.1103/PhysRevLett.71.959©1993 American Physical Society
We report a precision measurement of the parity-violating asymmetry $A_{PV}$ in elastic scattering longitudinally polarized electrons from $^{208}$Pb. measure $A_{PV}=550\pm 16 {\rm (stat)}\pm 8\ (syst)}$ parts per billion, leading to an extraction neutral weak form factor $F_W(Q^2 = 0.00616\ GeV}^2) 0.368 \pm 0.013$. Combined with our previous measurement, extracted neutron skin thickness is $R_n-R_p=0.283 0.071$~fm. The result also yields first significant direct interior density...
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...
The ratio of the proton elastic electromagnetic form factors, ${G}_{\mathit{Ep}}/{G}_{\mathit{Mp}}$, was obtained by measuring ${P}_{t}$ and ${P}_{\ensuremath{\ell}}$, transverse longitudinal recoil polarization components, respectively, for $\stackrel{\ensuremath{\rightarrow}}{e}p\ensuremath{\rightarrow}e\stackrel{\ensuremath{\rightarrow}}{p}$reaction in four-momentum transfer squared range 0.5 to $3.5\phantom{\rule{0.3em}{0ex}}\text{GeV}{}^{2}$. In single-photon exchange approximation,...
We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling ${\ensuremath{\alpha}}^{\ensuremath{'}}$ to electrons. Such particle ${A}^{\ensuremath{'}}$ can be produced in electron-nucleus fixed-target scattering and then decay an ${e}^{+}{e}^{\ensuremath{-}}$ pair, producing narrow resonance QED trident spectrum. Using APEX test run data, we searched mass range 175--250 MeV, found no evidence...
We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in elastic scattering longitudinally polarized electrons from ^{48}Ca. measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and charge minus F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model) fm is relatively thin yet consistent with many model...
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...
The neutron longitudinal and transverse asymmetries A1n A2n have been extracted from deep inelastic scattering of polarized electrons by a He3 target at incident energies 19.42, 22.66, 25.51 GeV. measurement allows for the determination spin structure functions g1n(x, Q2) g2n(x, over range 0.03<x<0.6 an average Q2 2 (GeV/c)2. data are used evaluation Ellis-Jaffe Bjorken sum rules. function is small negative within our measurement, yielding integral ∫0.030.6g1n(x)dx=−0.028±0.006 (stat)±0.006...
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...
We have measured the parity-violating electroweak asymmetry in elastic scattering of polarized electrons from protons. Significant contributions to this could arise strange form factors nucleon. The is $A=\ensuremath{-}15.05\ifmmode\pm\else\textpm\fi{}0.98(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.56(\mathrm{syst})\phantom{\rule{0.3em}{0ex}}\mathrm{ppm}$ at kinematic point $⟨{\ensuremath{\theta}}_{\mathrm{lab}}⟩=12.3\ifmmode^\circ\else\textdegree\fi{}$ and...
We present the first measurements of $\stackrel{\ensuremath{\rightarrow}}{e}p\ensuremath{\rightarrow}ep\ensuremath{\gamma}$ cross section in deeply virtual Compton scattering (DVCS) regime and valence quark region. The ${Q}^{2}$ dependence (from 1.5 to $2.3\text{ }\text{ }{\mathrm{GeV}}^{2}$) helicity-dependent indicates twist-2 dominance DVCS, proving that generalized parton distributions (GPDs) are accessible experiment at moderate ${Q}^{2}$. helicity-independent is also measured...
We have measured the transverse asymmetry ${A}_{{T}^{\ensuremath{'}}}$ in ${}^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{e}{,e}^{\ensuremath{'}})$ quasielastic scattering Hall A at Jefferson Laboratory with high precision for ${Q}^{2}$ values from 0.1 to $0.6(\mathrm{GeV}/c{)}^{2}$. The neutron magnetic form factor ${G}_{M}^{n}$ was extracted based on Faddeev calculations ${Q}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.1$ and...
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 present experiment exploits the interference between Deeply Virtual Compton Scattering (DVCS) and Bethe-Heitler processes to extract imaginary part of DVCS amplitudes on neutron deuteron from helicity-dependent D$({\vec e},e'\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ $x_B$=0.36. We a linear combination generalized parton distributions (GPDs) particularly sensitive $E_q$, least constrained GPD. A model dependent constraint contribution up down quarks nucleon spin is deduced.
This paper was published online on 20 May 2005 without several of the authors’ corrections incorporated. Equation (13) has been replaced. The captions Figs. 16–18 have also Typographical errors pages 4, 6, 14, 15, 18, 19, 22, and 24 all corrected. corrected as 8 June 2005. text is correct in printed version journal.Received 6 2005DOI:https://doi.org/10.1103/PhysRevC.71.069902©2005 American Physical Society
We present final results on the photon electroproduction ($\vec{e}p\rightarrow ep\gamma$) cross section in deeply virtual Compton scattering (DVCS) regime and valence quark region from Jefferson Lab experiment E00-110. Results an analysis of a subset these data were published before, but has been improved which is described here at length, together with details experimental setup. Furthermore, additional have analyzed resulting sections new kinematic settings, for total 588 bins. $Q^2$-...
The genetic algorithm (GA) is a powerful technique that implements the principles nature uses in biological evolution to optimize multidimensional nonlinear problem. GA works especially well for problems with large number of local extrema, where traditional methods (such as conjugate gradient, steepest descent, and others) fail or, at best, underperform. field accelerator physics, among others, abounds which lend themselves optimization via GAs. In this paper, we report on successful...
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.
A high precision measurement of the transverse spin-dependent asymmetry ${A}_{{T}^{\ensuremath{'}}}$ in ${}^{3}\mathrm{He}\ensuremath{\rightarrow}(\stackrel{\ensuremath{\rightarrow}}{e}{,e}^{\ensuremath{'}})$ quasielastic scattering was performed Hall at Jefferson Lab values squared four-momentum transfer, ${Q}^{2},$ between 0.1 and 0.6 $(\mathrm{G}\mathrm{e}\mathrm{V}/{c)}^{2}.$ is sensitive to neutron magnetic form factor, ${G}_{M}^{n}.$ Values ${G}_{M}^{n}$ ${Q}^{2}=0.1$...
We present data on the inclusive scattering of polarized electrons from a 3He target at energies 0.862 to 5.06 GeV, obtained angle 15.5°. Our include measurements quasielastic peak, through nucleon resonance region, and beyond, were used determine virtual photon cross-section difference σ1/2−σ3/2. extract extended Gerasimov-Drell-Hearn integral for neutron in range four-momentum transfer squared Q2 0.1–0.9 GeV2.Received 15 May 2002DOI:https://doi.org/10.1103/PhysRevLett.89.242301©2002...
We have measured the spin structure functions $g_1$ and $g_2$ of $^3$He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.07 GeV off target 15.5$^{\circ}$ angle. Excitation covered resonance onset deep inelastic regions. determined for first time $Q^2$ evolution $\Gamma_1(Q^2)=\int_0^{1} g_1(x,Q^2) dx$, $\Gamma_2(Q^2)=\int_0^1 g_2(x,Q^2) dx$ $d_2 (Q^2) = \int_0^1 x^2[ 2g_1(x,Q^2) + 3g_2(x,Q^2)] neutron range 0.1 GeV$^2$ $\leq Q^2...