A5031572564- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Advanced NMR Techniques and Applications
- High-Energy Particle Collisions Research
- Quantum, superfluid, helium dynamics
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Nuclear physics research studies
- Nuclear Physics and Applications
- Dark Matter and Cosmic Phenomena
- Gyrotron and Vacuum Electronics Research
- Neutrino Physics Research
- Advanced Chemical Physics Studies
- Radioactive Decay and Measurement Techniques
- Atomic and Molecular Physics
- Quantum and Classical Electrodynamics
- Crystallography and Radiation Phenomena
- Electron and X-Ray Spectroscopy Techniques
- Seismic Imaging and Inversion Techniques
- Cellular Automata and Applications
- Cold Fusion and Nuclear Reactions
North Carolina Central University
2014-2020
University of Virginia
2019
University of Ljubljana
2018
Old Dominion University
2007-2017
Istituto Superiore di Sanità
2015
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2015
Thomas Jefferson National Accelerator Facility
2012
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$\sigma$....
The Polarized Electrons for Positrons experiment at the injector of Continuous Electron Beam Accelerator Facility has demonstrated first time efficient transfer polarization from electrons to positrons produced by polarized bremsstrahlung radiation induced a electron beam in high-Z target. Positron up 82% have been measured an initial momentum 8.19 MeV/c, limited only polarization. This technique extends positron capabilities GeV MeV beams, and opens access physics wide community.
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 deeply virtual ${\ensuremath{\pi}}^{0}$ electroproduction cross-section measurements at ${x}_{B}=0.36$ and three different ${Q}^{2}$ values ranging from 1.5 to $2\text{ }\text{ }{\mathrm{Ge}\mathrm{V}}^{2}$, obtained Jefferson Lab Hall A experiment E07-007. The Rosenbluth technique is used separate the longitudinal transverse responses. Results demonstrate that cross section dominated by its component and, thus, far asymptotic limit predicted perturbative quantum chromodynamics....
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...
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 ${g}_{2}$,...
The parity-violating asymmetries between a longitudinally polarized electron beam and an unpolarized deuterium target have been measured recently. measurement covered two kinematic points in the deep-inelastic scattering region five nucleon resonance region. We provide here details of experimental setup, data analysis, results on all asymmetry measurements including those inclusive pion production beam-normal asymmetries. were used to extract electron-quark weak effective couplings, provided...
We have performed precision measurements of the double-spin virtual-photon asymmetry $A_1$ on neutron in deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer. Our data cover a wide kinematic range $0.277 \leq x 0.548$ at average $Q^2$ value 3.078~(GeV/c)$^2$, doubling available high-precision this $x$ range. combined our results with world proton targets to extract ratio polarized-to-unpolarized parton distribution functions for up quarks and down same are...
We report the first measurement of target single-spin asymmetry, A(y), in quasielastic scattering from inclusive reaction (3)He(↑)(e,e') on a (3)He gas polarized normal to lepton plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise interference between one- and two-photon exchange processes which sensitive details substructure nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high...
We report on parity-violating asymmetries in the nucleon resonance region measured using inclusive inelastic scattering of 5–6 GeV longitudinally polarized electrons off an unpolarized deuterium target. These results are first asymmetry data beyond Δ(1232). They provide a verification quark-hadron duality—the equivalence quark- and hadron-based pictures nucleon—at (10–15)% level this electroweak observable, which is dominated by contributions from γZ interference structure functions. In...
We report the first measurement of target-normal single-spin asymmetry in deep-inelastic scattering from inclusive reaction ${^{3}\mathrm{He}}^{\ensuremath{\uparrow}}(e,{e}^{\ensuremath{'}})X$ on a polarized $^{3}\mathrm{He}$ gas target. Assuming time-reversal invariance, this is strictly zero Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using 5.89 GeV electron beam, covers range $1.7<W<2.9\text{...
The proton is composed of quarks and gluons, bound by the most elusive mechanism strong interaction called confinement. In this work, dynamics gluons are investigated using deeply virtual Compton scattering (DVCS): produced a multi-GeV electron, highly photon scatters off which subsequently radiates high energy photon. Similarly to holography, measuring not only magnitude but also phase DVCS amplitude allows perform 3D images internal structure proton. made accessible through...
An experiment to measure single-spin asymmetries of semi-inclusive production charged pions in deep-inelastic scattering on a transversely polarized $^{3}\mathrm{He}$ target was performed at Jefferson Laboratory the kinematic region $0.16<x<0.35$ and $1.4<{Q}^{2}<2.7$ ${\mathrm{GeV}}^{2}$. Pretzelosity $^{3}\mathrm{He}$, which are expressed as convolution ${h}_{1T}^{\ensuremath{\perp}}$ transverse-momentum-dependent distribution functions Collins fragmentation leading order, were measured...
Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25≤x≤0.90), in both the deep-inelastic resonance regions, by scattering longitudinally polarized electrons beam energies of 4.7 5.9 GeV from a transversely 3He target. In this dedicated experiment, spin structure function g3He2 was determined with precision x, neutron twist-3 matrix element dn2 ⟨Q2⟩ 3.21 4.32 GeV2/c2, an about 10−5. Our results are found to be agreement lattice QCD calculations resolve...
We report the first longitudinal-transverse separation of deeply virtual exclusive ${\ensuremath{\pi}}^{0}$ electroproduction cross section off neutron and coherent deuteron. The corresponding four structure functions $d{\ensuremath{\sigma}}_{L}/dt$, $d{\ensuremath{\sigma}}_{T}/dt$, $d{\ensuremath{\sigma}}_{LT}/dt$, $d{\ensuremath{\sigma}}_{TT}/dt$ are extracted as a function momentum transfer to recoil system at ${Q}^{2}=1.75\text{ }\text{ }{\mathrm{GeV}}^{2}$ ${x}_{B}=0.36$....
We report the measurement of beam-target double spin asymmetries $({A}_{\text{LT}})$ in inclusive production identified hadrons, $\stackrel{P\vec}{e}$ + ${}^{3}{\text{He}}^{\ensuremath{\uparrow}}\ensuremath{\rightarrow}h+X$, using a longitudinally polarized 5.9-GeV electron beam and transversely $^{3}\mathrm{He}$ target. Hadrons $({\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},{K}^{\ifmmode\pm\else\textpm\fi{}}$, proton) were detected at ${16}^{\ensuremath{\circ}}$ with an average...
We present a precise measurement of double-polarization asymmetries in the ^{3}He[over →](e[over →],e^{'}d) reaction. This particular process is uniquely sensitive probe hadron dynamics ^{3}He and structure underlying electromagnetic currents. The measurements have been performed around quasielastic kinematics at Q^{2}=0.25(GeV/c)^{2} for missing momenta up to 270 MeV/c. are fair agreement with state-of-the-art calculations terms their functional dependencies on p_{m} ω, but systematically...
Background: Measurements of the neutron charge form factor, ${G}_{E}^{n}$, are challenging because has no net charge. In addition, measurements factors must use nuclear targets which require accurately accounting for effects. Extracting ${G}_{E}^{n}$ with different and techniques provides an important test our handling these effects.Purpose: The goal measurement was to inclusive asymmetry technique extract factor at a four-momentum transfer...
Due to the lack of free neutron targets, studies structure are typically made by scattering electrons from either $^2$H or $^3$He targets. In order extract useful information a target, one must understand how in system differs taking into account nuclear effects such as final state interactions and meson exchange currents. The target single spin asymmetry $A_y^0$ is an ideal probe effects, any deviation zero indicates beyond plane wave impulse approximation. New measurements at $Q^2$ 0.46...
We present a conceptual design for novel continuous wave electron-linac based high-intensity high-brightness slow-positron production source with projected intensity on the order of 1010 e+/s. Reaching this in our relies transport positrons (T+ below 600 keV) from electron-positron pair converter target to low-radiation and low-temperature area moderation high-efficiency cryogenic rare gas moderator, solid Ne. This progressed through Monte Carlo optimizations of: electron/positron beam...