Sebastian Kuhn
A5028022109- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Atomic and Molecular Physics
- Electron and X-Ray Spectroscopy Techniques
- Quantum chaos and dynamical systems
- Computational Physics and Python Applications
- European history and politics
- Pulsars and Gravitational Waves Research
- International Science and Diplomacy
- Muon and positron interactions and applications
Old Dominion University
2015-2025
Christopher Newport University
2023
University of York
2023
University of Regina
2023
AOK
2023
Jena University Hospital
2022
Friedrich Schiller University Jena
2022
CEA Paris-Saclay
2018
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2018
Hampton University
2018
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 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 present a comprehensive new global QCD analysis of polarized inclusive deep-inelastic scattering, including the latest high-precision data on longitudinal and transverse polarization asymmetries from Jefferson Lab elsewhere. The is performed using iterative Monte Carlo fitting technique which generates stable fits to parton distribution functions (PDFs) with statistically rigorous uncertainties. Inclusion leads reduction in PDF errors for valence sea quarks, as well gluon uncertainty at...
We have measured the spin structure functions g2p and g2d virtual photon asymmetries A2p A2d over kinematic range 0.02⩽x⩽0.8 0.7⩽Q2⩽20GeV2 by scattering 29.1 32.3 GeV longitudinally polarized electrons from transversely NH3 6LiD targets. Our g2 approximately follows twist-2 Wandzura–Wilczek calculation. The twist-3 reduced matrix elements d2p d2n are less than two standard deviations zero. data inconsistent with Burkhardt–Cottingham sum rule if there is no pathological behavior as x→0....
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 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...
We present new data on the Bjorken sum $\overline \Gamma_1^{p-n}(Q^2)$ at 4-momentum transfer $ 0.021 \leq Q^2 0.496$ GeV$^2$. The were obtained in two experiments performed Jefferson Lab: EG4 polarized protons and deuterons, E97110 $^3$He from which neutron extracted. cover domain where chiral effective field theory ($\chi$EFT), leading of Strong Force large distances, is expected to be applicable. find that our predictions $\chi$EFT are only marginal agreement. This somewhat surprising as...
The spin structure functions of the proton and deuteron were measured during EG4 experiment at Jefferson Lab in 2006. Data collected for longitudinally polarized electron scattering off ${\mathrm{NH}}_{3}$ ${\mathrm{ND}}_{3}$ targets, ${Q}^{2}$ values as small 0.012 0.02 ${\mathrm{GeV}}^{2}$, respectively, using CEBAF Large Acceptance Spectrometer. This is archival paper that summarizes previously reported results ${g}_{1}$, ${A}_{1}{F}_{1}$, their moments...
We have measured the spin structure functions g2p and g2d virtual photon asymmetries A2p A2d over kinematic range 0.02≤x≤0.8 1.0≤Q2≤30 (GeV/c)2 by scattering 38.8 GeV longitudinally polarized electrons from transversely NH3 6LiD targets. The absolute value of A2 is significantly smaller than R positivity limit range, while g2 consistent with twist-2 Wandzura-Wilczek calculation. obtain results for twist-3 reduced matrix elements d2p, d2d d2n. Burkhardt-Cottingham sum rule integral ∫g2(x)dx...
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.
We present the Bjorken integral extracted from Jefferson Lab experiment EG1b for $0.05<{Q}^{2}<2.92\text{ }\text{ }{\mathrm{GeV}}^{2}$. The is fit to extract twist-4 element ${f}_{2}^{p\ensuremath{-}n}$ which appears be relatively large and negative. Systematic studies of this higher twist analysis establish its legitimacy at ${Q}^{2}$ around $1\text{ also performed an isospin decomposition generalized forward spin polarizability ${\ensuremath{\gamma}}_{0}$. Although isovector part provides...
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...
We have measured the proton and deuteron spin structure functions g_1^p g_1^d in region of nucleon resonances for W^2 < 5 GeV^2 $Q^2\simeq 0.5$ 1.2$ by inelastically scattering 9.7 GeV polarized electrons off $^{15}NH_3$ $^{15}ND_3$ targets. observe significant resonance region. used present results, together with deep-inelastic data at higher W^2, to extract $\Gamma(Q^2)\equiv\int_0^1 g_1(x,Q^2) dx$. This is first information on low-Q^2 evolution Gamma toward Gerasimov-Drell-Hearn limit Q^2 = 0.
We determined the structure function ratio ${R}_{\mathrm{EMC}}^{d}={F}_{2}^{d}/({F}_{2}^{n}+{F}_{2}^{p})$ from recently published ${F}_{2}^{n}/{F}_{2}^{d}$ data taken by BONuS experiment using CLAS at Jefferson Lab. This deviates unity, with a slope $d{R}_{\mathrm{EMC}}^{d}/dx=\ensuremath{-}0.10\ifmmode\pm\else\textpm\fi{}0.05$ in range of Bjorken $x$ 0.35 to 0.7, for invariant mass $W>1.4$ GeV and ${Q}^{2}>1\phantom{\rule{4pt}{0ex}}{\mathrm{GeV}}^{2}$. The observed EMC effect these...
We report on the first measurement of beam-spin asymmetry in exclusive process coherent deeply virtual Compton scattering off a nucleus. The experiment uses 6 GeV electron beam from Continuous Electron Beam Accelerator Facility (CEBAF) accelerator at Jefferson Lab incident pressurized ^{4}He gaseous target placed front CEBAF Large Acceptance Spectrometer (CLAS). scattered is detected by CLAS and photon dedicated electromagnetic calorimeter forward angles. To ensure exclusivity process,...