A5018396057- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Nuclear physics research studies
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Neutrino Physics Research
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Cosmology and Gravitation Theories
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Astronomical and nuclear sciences
- Superconducting Materials and Applications
- Advanced Chemical Physics Studies
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
University of Chicago
2022-2025
University of Illinois Chicago
2021-2025
A. Alikhanyan National Laboratory
2024
Institute of High Energy Physics
2023-2024
University of Antwerp
2024
Indo-American Center
2024
Mississippi State University
2020-2023
Virginia Tech
2023
Al-Zaytoonah University of Jordan
2023
Shandong University
2023
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
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 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 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 investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2=2 (GeV/c)2, xB=1.2, in an (e, e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing momentum greater than Fermi of nucleons nucleus far delta excitation, short-range nucleon-nucleon correlations are predicted dominate reaction. For (9.5+/-2)% events, recoiling partner proton was observed back-to-back vector, experimental signature correlations.
We have measured the parity-violating electroweak asymmetry in elastic scattering of polarized electrons from 4He at an average angle <theta(lab)> = 5.7 degrees and a four-momentum transfer Q2 0.091 GeV2 . From these data, for first time, strange electric form factor nucleon G(E)s can be isolated. The A(PV) (6.72 +/- 0.84(stat) 0.21(syst) x 10(-6) yields value -0.038 0.042(stat) 0.010(syst), consistent with zero.
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.
We report the most precise measurement to date of a parity-violating asymmetry in elastic electron-proton scattering. The was carried out with beam energy 3.03 GeV and scattering angle =6 degrees, result A_PV = -1.14 +/- 0.24 (stat) 0.06 (syst) parts per million. From this we extract, at Q^2 0.099 GeV^2, strange form factor combination G_E^s + 0.080 G_M^s 0.030 0.025 0.006 0.012 (FF) where first two errors are experimental last error is due uncertainty neutron electromagnetic factor. This...
We have measured the neutron spin asymmetry A(n)(1) with high precision at three kinematics in deep inelastic region x=0.33, 0.47, and 0.60, Q(2)=2.7, 3.5, 4.8 (GeV/c)(2), respectively. Our results unambiguously show, for first time, that crosses zero around x=0.47 becomes significantly positive x=0.60. Combined world proton data, polarized quark distributions were extracted. results, general, agree relativistic constituent models perturbative quantum chromodynamics (PQCD) analyses based on...
The electric form factor of the neutron was determined from studies reaction ${}^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{e},{e}^{\ensuremath{'}}n)pp$ in quasielastic kinematics Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a target which nuclear polarization oriented perpendicular to momentum transfer. detected magnetic spectrometer coincidence with neutrons that registered large-solid-angle detector. More than...
The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV and beam energy E =3.48 to be A_PV -23.80 +/- 0.78 (stat) 0.36 (syst) parts per million. This result is consistent with zero contribution strange quarks combination electric magnetic form factors G_E^s + 0.517 G_M^s 0.003 0.010 0.004 0.009 (ff), where third error due limits precision on electromagnetic...
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 spin rotation parameter $Q$ has been measured for $p$-$^{40}\mathrm{Ca}$ elastic scattering at 497 MeV $0.01<~\ensuremath{-}t<~0.15$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ with use of the new high-resolution spectrometer focalplane polarimeter. In conjunction analyzing power and differential cross section, this measurement uniquely determines amplitudes up to an arbitrary phase. A parameter-free analysis within Glauber diffractive approximation $N\ensuremath{-}N$ phase-shift...
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 report the first measurement of double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7 GeV{2}. corresponding neutron asymmetries were extracted from measured and proton over cross section ratios using effective polarization approximation. These new data probe transverse momentum dependent parton distribution...
We report the first measurement of target single-spin asymmetries (A$_N$) in inclusive hadron production reaction, $e~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a transversely polarized $^3$He target. The experiment was conducted at Jefferson Lab Hall A 5.9-GeV electron beam. Three types hadrons ($\pi^{\pm}$, $\text{K}^{\pm}$ and proton) were detected transverse momentum range 0.54 $<p_T<$ 0.74 GeV/c. $x_F$ for pions -0.29 $<x_F<$ -0.23 kaons -0.25 $<x_F<$-0.18. observed asymmetry...
Quasielastic $^{12}$C$(e,e'p)$ scattering was measured at space-like 4-momentum transfer squared $Q^2$~=~8, 9.4, 11.4, and 14.2 (GeV/c)$^2$, the highest ever achieved to date. Nuclear transparency for this reaction extracted by comparing yield that expected from a plane-wave impulse approximation calculation without any final state interactions. The consistent with no $Q^2$ dependence, up proton momenta of 8.5~GeV/c, ruling out quantum chromodynamics effect color scales in exclusive...
An experiment measuring electroproduction of hypernuclei has been performed in hall A at Jefferson Lab on a 12C target. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets ring imaging Cherenkov detector were added the standard equipment. unprecedented energy resolution less than 700 keV FWHM achieved. Thus, observed (Lambda)(12)B spectrum shows for first time identifiable strength core-excited region between ground-state s-wave...
We have measured the transverse asymmetry AT' in quasielastic 3He→(e→,e') process with high precision at Q2 values from 0.1 to 0.6(GeV/c)2. The neutron magnetic form factor GMn was extracted of and 0.2(GeV/c)2 using a nonrelativistic Faddeev calculation which includes both final-state interactions (FSI) meson-exchange currents (MEC). Theoretical uncertainties due FSI MEC effects were constrained measurement spin-dependent threshold region 3He→(e→,e'). also 0.3 0.6(GeV/c)2 based on plane wave...
Spin-flip probabilities have been measured for inelastic proton scattering from $^{40}\mathrm{Ca}$ at 319 MeV angles between 3\ifmmode^\circ\else\textdegree\fi{} and 12\ifmmode^\circ\else\textdegree\fi{} excitation energies up to about 40 MeV. These data can be directly related the relative [(spin transfer)/(no spin transfer)] nuclear response via one model-dependent variable. Nuclear excitations appear relatively suppressed low but surprisingly enhanced highest intermediate angles. Many...
We report the first measurement of target single spin asymmetries charged kaons produced in semi-inclusive deep inelastic scattering electrons off a transversely polarized $^3{\rm{He}}$ target. Both Collins and Sivers moments, which are related to nucleon transversity distributions, respectively, extracted over kinematic range 0.1$
We report on the results of E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement twist-3 matrix element ${d}_{2}$ neutron (${d}_{2}^{n}$) was conducted. The quantity ${d}_{2}^{n}$ represents average color Lorentz force struck quark experiences deep inelastic electron scattering event off due to its interaction with hadronizing remnants. This determined from linear combination third moments $^{3}\mathrm{He}$ spin structure functions, ${g}_{1}$ and ${g}_{2}$,...