Z.-E. Meziani
A5015177727- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Particle Detector Development and Performance
- Advanced NMR Techniques and Applications
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Electron and X-Ray Spectroscopy Techniques
- Advanced Chemical Physics Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Physics of Superconductivity and Magnetism
- Photonic and Optical Devices
- Scientific Research and Discoveries
- Semiconductor materials and devices
- Astrophysics and Cosmic Phenomena
- Muon and positron interactions and applications
Argonne National Laboratory
1990-2024
Idaho National Laboratory
2024
Temple University
2014-2023
Weizmann Institute of Science
2023
Universidade de Santiago de Compostela
2023
University of Aveiro
2022
University of York
2020-2021
Thomas Jefferson National Accelerator Facility
2017-2020
William & Mary
2020
Williams (United States)
2020
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on structure and interactions gluon-dominated matter, with intent to articulate it broader nuclear community. It was commissioned by managements Brookhaven National Laboratory (BNL) Thomas Jefferson Accelerator Facility (JLab) objective presenting a summary scientific opportunities goals EIC as follow-up 2007 NSAC Long Range plan. document is culmination community-wide effort in following series workshops...
We report the first measurement of parity-violating asymmetry APV in elastic scattering polarized electrons from Pb208. is sensitive to radius neutron distribution (Rn). The result APV=0.656±0.060(stat)±0.014(syst) ppm corresponds a difference between radii and proton distributions Rn−Rp=0.33−0.18+0.16 fm provides electroweak observation skin which expected heavy, neutron-rich nucleus.Received 12 January 2012DOI:https://doi.org/10.1103/PhysRevLett.108.112502© 2012 American Physical Society
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
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...
We report on a precision measurement of the neutron spin structure function ${g}_{1}^{n}$ using deep inelastic scattering polarized electrons by ${}^{3}\mathrm{He}$. For kinematic range $0.014<x<0.7$ and $1<{Q}^{2}<17(\mathrm{GeV}/c{)}^{2}$, we obtain $\ensuremath{\int}{0.014}^{0.7}{g}_{1}^{n}(x)dx\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}0.036\ifmmode\pm\else\textpm\fi{}0.004(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{syst})$ at an average...
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...
Deep-inelastic electron scattering from $^{40}\mathrm{Ca}$, $^{48}\mathrm{Ca}$, and $^{56}\mathrm{Fe}$ has been measured at 60\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, 140\ifmmode^\circ\else\textdegree\fi{} inelasticities up to including the $\ensuremath{\Delta}(3,3)$ region. Longitudinal response functions in momentum interval $300 \mathrm{MeV}/c<|\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}|<600 \mathrm{MeV}/c$ were extracted. The experimental Coulomb...
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 present measurements of the ratio proton elastic electromagnetic form factors, μpGEp/GMp. The Jefferson Lab Hall A Focal Plane Polarimeter was used to determine longitudinal and transverse components recoil polarization in ep scattering; these is proportional two factors. These data reproduce observation Jones et al. [Phys. Rev. Lett. 84, 1398 (2000)], that factor decreases significantly from unity above Q2=1GeV2.Received 29 May 2001DOI:https://doi.org/10.1103/PhysRevC.64.038202©2001...
We report the first measurement of target single spin asymmetries in semi-inclusive $^3{He}(e,e'\pi^\pm)X$ reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using 5.9 GeV electron beam, covers range 0.14 $< x <$ 0.34 with 1.3 $<Q^2<$ 2.7 GeV$^2$. Collins and Sivers moments were extracted from azimuthal angular dependence measured asymmetries. $\pi^\pm$ for $^3$He are consistent zero, except $\pi^+$ moment $x=0.34$, which deviates zero by 2.3$\sigma$....
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 report new measurements of the parity-violating asymmetry ${A}_{\mathrm{PV}}$ in elastic scattering 3 GeV electrons off hydrogen and $^{4}\mathrm{He}$ targets with $⟨{\ensuremath{\theta}}_{\mathrm{lab}}⟩\ensuremath{\approx}6.0\ifmmode^\circ\else\textdegree\fi{}$. The result is ${A}_{\mathrm{PV}}=\mathbf{(}+6.40\ifmmode\pm\else\textpm\fi{}0.23(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.12(\mathrm{syst})\mathbf{)}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$....
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...
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on structure and interactions gluon-dominated matter, with intent to articulate it broader nuclear community. It was commissioned by managements Brookhaven National Laboratory (BNL) Thomas Jefferson Accelerator Facility (JLab) objective presenting a summary scientific opportunities goals EIC as follow-up 2007 NSAC Long Range plan. document is culmination community-wide effort in following series workshops...
Deep-inelastic inclusive electron-scattering cross sections from $^{40}\mathrm{Ca}$, $^{48}\mathrm{Ca}$, and $^{56}\mathrm{Fe}$ have been measured at 60\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, 140\ifmmode^\circ\else\textdegree\fi{} energy transfers including the $\ensuremath{\Delta}(3, 3)$ region. The transverse response function in momentum interval 300 MeV/c |q| 600 was extracted by Rosenbluth prescription. Different theoretical approaches to quasielastic...
We report on measurements of the neutron spin asymmetries An1,2 and polarized structure functions gn1,2 at three kinematics in deep inelastic region, with x=0.33, 0.47, 0.60 Q2=2.7, 3.5, 4.8(GeV∕c)2, respectively. These were performed using a 5.7GeV longitudinally electron beam 3He target. The results for An1 gn1 x=0.33 are consistent previous world data and, two higher-x points, have improved precision by about an order magnitude. new show zero crossing around x=0.47 value x=0.60 is...
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 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...
Unpolarized and beam-polarized fourfold cross sections (d^{4}σ/dQ^{2}dx_{B}dtdϕ) for the ep→e^{'}p^{'}γ reaction were measured using CLAS detector 5.75-GeV polarized electron beam of Jefferson Lab accelerator, 110 (Q^{2},x_{B},t) bins over widest phase space ever explored in valence-quark region. Several models generalized parton distributions (GPDs) describe data well at most our kinematics. This increases confidence that we understand GPD H, expected to be dominant contributor these...