A5060155562- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Electron and X-Ray Spectroscopy Techniques
- Advanced NMR Techniques and Applications
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Crystallography and Radiation Phenomena
- Advanced Chemical Physics Studies
- Neutrino Physics Research
- Electron Spin Resonance Studies
- Quantum, superfluid, helium dynamics
- Nuclear reactor physics and engineering
- Organic and Molecular Conductors Research
- Inorganic Fluorides and Related Compounds
- Scientific Research and Discoveries
- Physics of Superconductivity and Magnetism
- Astrophysics and Cosmic Phenomena
Thomas Jefferson National Accelerator Facility
2014-2024
Lomonosov Moscow State University
2011-2023
University of York
2020-2023
Louisiana State University
2022
Fermi National Accelerator Laboratory
2020
Institut de Physique
2014-2018
Campbell Collaboration
2012-2014
Newport News Public Schools
2012
Moscow State University
2012
Institute of Nuclear Physics
2012
Studies of the structure excited baryons are key factors to N* program at Jefferson Lab (JLab). Within first year data taking with Hall B CLAS12 detector following 12 GeV upgrade, a dedicated experiment will aim extract electrocouplings high photon virtualities Q 2 . This allow exploration resonances highest ever achieved, kinematic reach up = high-Q make it possible probe nucleon structures distance scales ranging from where effective degrees freedom, such as constituent quarks, dominant...
The transition helicity amplitudes from the proton ground state to $P_{11}(1440)$ and $D_{13}(1520)$ excited states ($\gamma_{v}pN^*$ electrocouplings) were determined analysis of nine independent one-fold differential $\pi^{+} \pi^{-} p$ electroproduction cross sections off a target, taken with CLAS at photon virtualities 0.25\enskip {\rm GeV$^{2}$} $<$ $Q^{2}$ 0.60 \enskip GeV$^{2}$}. phenomenological reaction model was employed for separation resonant non-resonant contributions final...
Understanding the strong interaction dynamics that govern emergence of hadron mass (EHM) represents a challenging open problem in Standard Model. In this paper we describe new opportunities for gaining insight into EHM from results on nucleon resonance (N*) electroexcitation amplitudes (i.e., γvpN* electrocouplings) range up to 1.8 GeV virtual photon four-momentum squared virtualities Q2) 7.5 GeV2 available exclusive meson electroproduction data acquired during 6-GeV era experiments at...
The topical workshop Strong QCD from Hadron Structure Experiments took place at Jefferson Lab November 6–9, 2019. Impressive progress in relating hadron structure observables to the strong mechanisms has been achieved ab initio description of a diverse array methods order expose emergent phenomena via quasi-particle formation. wealth experimental data and advances theory make it possible gain insight into interaction dynamics regime large quark–gluon coupling (the regime), which will address...
Photoproduction of charged pions pairs off protons is studied within the invariant masses final state hadrons from 1.6 to 2.4 GeV at Thomas Jefferson National Accelerator Facility with CLAS detector. The total and differential cross sections spin-density matrix elements are presented for isobars $p{\ensuremath{\rho}}^{0}(770), \mathrm{\ensuremath{\Delta}}{(1232)}^{++}{\ensuremath{\pi}}^{\ensuremath{-}}$, $\mathrm{\ensuremath{\Delta}}{(1232)}^{0}{\ensuremath{\pi}}^{+}$. data included in...
Recent CLAS data on the $p{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ electroproduction off protons at $1.3<W<1.57$ GeV and $0.25<{Q}^{2}<0.6 {\mathrm{GeV}}^{2}$ have been analyzed using a meson-baryon phenomenological model. By fitting nine onefold differential cross-section for each $W$ ${Q}^{2}$ bin, charged double-pion mechanisms are identified from their manifestations in observables. We extracted cross sections amplitudes of considered isobar channels as well coherent...
Exclusive neutral-pion electroproduction ($ep\to e^\prime p^\prime \pi^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4\sigma/dtdQ^2dx_Bd\phi_\pi$ structure functions $\sigma_T+\epsilon\sigma_L, \sigma_{TT}$ $\sigma_{LT}$ as of $t$ were obtained over wide range $Q^2$ $x_B$. The data are compared Regge handbag theoretical calculations. Analyses in both frameworks find that large dominance transverse processes is necessary...
Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this true, then hyperon-nucleon interactions will play a significant part star equation state (EOS). Yet, compared other elastic scattering processes, there very little data $\Lambda$-$N$ scattering. This experiment utilized CLAS detector study $\Lambda p \rightarrow \Lambda p$ cross section incident $\Lambda$ momentum range 0.9-2.0 GeV/c. first reaction several decades. The new sections have...
Background: Energetic quarks in nuclear DIS propagate through the medium. Processes that are believed to occur inside nuclei include quark energy loss medium-stimulated gluon bremsstrahlung and intra-nuclear interactions of forming hadrons. More data required gain a more complete understanding these effects. Purpose: To test theoretical models parton transport hadron formation, we compared their predictions for kinematic dependence pion production nuclei. Methods: We have measured...
We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction process. In this reaction, two hadrons are produced opposite hemispheres along z axis virtual photon-target nucleon center-of-mass frame, with hadron current-fragmentation region and second target-fragmentation region. The data were taken longitudinally polarized electron beams 10.2 10.6 GeV incident on an unpolarized liquid-hydrogen target using...
Beam asymmetries for the reactions gamma p -> pi0 and n pi+ have been measured with CEBAF Large Acceptance Spectrometer (CLAS) a tagged, linearly polarized photon beam energies from 1.102 to 1.862 GeV. A Fourier moment technique extracting experimental data is described. The results reported here possess greater precision finer energy resolution than previous measurements. Our both pion appear favor SAID Bonn-Gatchina scattering analyses over older Mainz MAID predictions. After incorporating...
This paper reports new exclusive cross sections for $e p \to e' \pi^+ \pi^- p'$ using the CLAS detector at Jefferson Laboratory. These results are presented first time photon virtualities 2.0 GeV^2 < Q^2 5.0 in center-of-mass energy range 1.4 GeV W GeV, which covers a large part of nucleon resonance region. Using model developed phenomenological analysis electroproduction data, we see strong indications that relative contributions from resonant 1.74 increase with $Q^2$. data considerably...
The first CLAS12 experiments will provide high-precision data on inclusive electron scattering observables at a photon virtuality ${Q}^{2}$ ranging from 0.05 to $12\phantom{\rule{0.16em}{0ex}}{\mathrm{GeV}}^{2}$ and center-of-mass energies $W$ up 4 GeV. In view of this endeavor, we present the modeling resonant contributions observables. As input, use existing CLAS electrocoupling results obtained exclusive meson electroproduction off protons, evaluate for time based experimental nucleon...
The analysis of the nine 1-fold differential cross sections for γr,vp→π+π−p photo- and electroproduction reactions obtained with CLAS detector at Jefferson Laboratory was carried out goal to establish contributing resonances in mass range from 1.6 GeV 1.8 GeV. In order describe data Q2-independent resonance masses hadronic decay widths Q2 below 1.5 GeV2, it found that an N′(1720)3/2+ state is required addition already well-established nucleon resonances. This work demonstrates combined...
We investigate the properties of hidden-charm pentaquark-like resonances first observed by LHCb Collaboration in 2015, measuring polarization transfer ${K}_{LL}$ between incident photon and outgoing proton exclusive photoproduction $J/\ensuremath{\psi}$ near threshold. present a estimate sensitivity this observable to pentaquark photocouplings hadronic branching ratios, extend our predictions case initial-state helicity correlation ${A}_{LL}$, using polarized target. These results serve as...
The observation of beam spin asymmetries in two-pion production semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. data presented here were taken the fall 2018 with CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron delivered by CEBAF at JLab. measured provide first opportunity to extract parton distribution function $e(x)$, which provides information about interaction between gluons and quarks, collinear framework that offers...
The polarized cross-section ratio σ_{LT^{'}}/σ_{0} from hard exclusive π^{-}Δ^{++} electroproduction off an unpolarized hydrogen target has been extracted based on beam-spin asymmetry measurements using a 10.2 GeV/10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. study, which provides first observation of this channel in deep-inelastic regime, focuses very forward-pion kinematics valence photon virtualities ranging 1.5 GeV^{2} up to 7 GeV^{2}. reaction novel...
This paper reports on the most comprehensive data set obtained differential and fully integrated cross sections for process $e p \to e' \pi^{+} \pi^{-} $. The were collected with CLAS detector at Jefferson Laboratory. Measurements carried out in so-far unexplored kinematic region of photon virtuality 0.2 $<$ $Q^{2}$ 0.6 GeV$^{2}$ invariant mass final hadron system $W$ from 1.3 to 1.57 GeV. For first time, nine independent 1-fold determined each bin covered by measurements. A phenomenological...