Related papers: Possible evidence of extended objects inside the p…
In the context of nucleon structure studies, Generalized Parton Distributions (GPDs) are crucial for understanding the correlation between the longitudinal momentum and the transverse position of partons inside the nucleon. A privileged…
Power corrections to the Q**2 behavior of the Nachtmann moments of the proton polarized structure function g1p are investigated at large Bjorken-x by developing a phenomenological fit of both the resonance (including the photon point) and…
Precise proton and neutron form factor measurements at Jefferson Lab, using spin observables, have recently made a significant contribution to the unraveling of the internal structure of the nucleon. Accurate experimental measurements of…
The E08-027 (g2p) experiment measured the spin structure functions of the proton at Jefferson Laboratory in Newport News, Va. Longitudinally polarized electrons were scattered from a transversely and longitudinally polarized solid ammonia…
The physics of electromagnetic excitation of nucleon resonances and of their relevance in nucleon structure studies are discussed. Preliminary data from the CLAS detector on the N-Delta(1232) transition multipoles, the helicity amplitudes…
Recent progress in the understanding of the nucleon is presented. The unpolarised structure functions are obtained with unprecedented precision from the combined H1 and ZEUS data and are used to extract proton parton distribution functions…
Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear…
The GEp-III and GEp-2$\gamma$ experiments were carried out in Jefferson Lab's (JLab's) Hall C from 2007-2008, to extend the knowledge of $G_E^p/G_M^p$ to the highest practically achievable $Q^2$ and to search for effects beyond the Born…
The photoproduction of $\pi^+\pi^-$ meson pairs off the proton has been studied in the reaction $\gamma p\to p\,\pi^+\pi^-$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas…
For over 100 years, scientists have investigated the properties of the proton, which is one of the most abundant components of visible matter in the universe. Nevertheless, researchers do not fully understand many details about its internal…
We present a physical model for polarized and unpolarized structure functions and parton density functions (PDFs) of the proton and the neutron. It reproduces the data on F_2^p(x,Q^2) for 0.00001<x<1 and 2.5<Q^2<5000 GeV^2,…
The neutron elastic magnetic form factor GMn has been extracted from quasielastic electron scattering data on deuterium with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic coverage of the measurement is…
A new scaling variable is introduced in terms of which nuclear shadowing in deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$. This variable can be interpreted as a measure of the number of gluons probed by the…
The observation of scaling in processes in which a weakly interacting probe delivers large momentum ${\bf q}$ to a many-body system simply reflects the dominance of incoherent scattering off target constituents. While a suitably defined…
A parton picture of inclusive quasi-elastic electron-nucleus scattering, where individual nucleons are treated as (non point-like) partons of the nucleus, is presented. All the necessary target-mass corrections to asymptotic scaling are…
Pion photoproduction in the $\overrightarrow\gamma\overrightarrow p \to \pi^0 p$ reaction has been measured in the FROST experiment at the Thomas Jefferson National Accelerator Facility. In this experiment, circularly polarized photons with…
For a long time people made the mistake of thinking the proton was understood. New experiments, ranging from form factors to deeply virtual Compton scattering, promise a new era of highly informative studies. Among the controversial topics…
We pursue the hypothesis that the events with a large rapidity gap, observed at HERA, reflect the scattering of electrons off lumps of wee partons inside the proton. A simple scaling behaviour is predicted for the diffractive structure…
The CLAS experiment E02-104, part of the EG2 run at Jefferson Lab, was performed to study the hadronization process using semi inclusive deep inelastic scattering off nuclei. Electron beam energy of 5 GeV and the CLAS large acceptance…
A phenomenological parameterization of the proton polarized structure function has been developed for x > 0.02 using deep inelastic data up to ~ 50 (GeV/c)**2 as well as available experimental results on both photo- and electro-production…