Deeply Virtual Compton Scattering and Generalized Parton Distributions at CLAS.

Deeply Virtual Compton Scattering and Generalized Parton Distributions at CLAS. PDF Author:
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Languages : en
Pages : 4

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Book Description
The exclusive electroproduction of real photons and mesons at high momentum transfer allows us to access the Generalized Parton Distributions (GPDs). The formalism of the GPDs provides a unified description of the hadronic structure in terms of quark and gluonic degrees of freedom. In particular, the Deeply Virtual Compton Scattering (DVCS), ep â e2p2Å, is one of the key reactions to determine the GPDs experimentally, as it is the simplest process that can be described in terms of GPDs. A dedicated experiment to study DVCS has been carried out in Hall B at Jefferson Lab. Beam-spin asymmetries, resulting from the interference of the Bethe-Heitler process and DVCS have been extracted over the widest kinematic range ever accessed for this reaction (1.2

Deeply Virtual Compton Scattering and Generalized Parton Distributions at CLAS.

Deeply Virtual Compton Scattering and Generalized Parton Distributions at CLAS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
The exclusive electroproduction of real photons and mesons at high momentum transfer allows us to access the Generalized Parton Distributions (GPDs). The formalism of the GPDs provides a unified description of the hadronic structure in terms of quark and gluonic degrees of freedom. In particular, the Deeply Virtual Compton Scattering (DVCS), ep â e2p2Å, is one of the key reactions to determine the GPDs experimentally, as it is the simplest process that can be described in terms of GPDs. A dedicated experiment to study DVCS has been carried out in Hall B at Jefferson Lab. Beam-spin asymmetries, resulting from the interference of the Bethe-Heitler process and DVCS have been extracted over the widest kinematic range ever accessed for this reaction (1.2

Generalized Parton Distributions And Deeply Virtual Compton Scattering At Clas

Generalized Parton Distributions And Deeply Virtual Compton Scattering At Clas PDF Author:
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Languages : en
Pages :

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Book Description
The deeply virtual Compton scattering is the simplest process to access the generalized parton distributions of the nucleon. A dedicated large statistics experiment for the measurement of deeply virtual Compton scattering with a 6 GeV polarized electron beam on a proton target has been performed at the Hall-B of Jefferson Laboratory with the CLAS spectrometer. The experiment covered a wide kinematic range, allowing the study of the beam spin asymmetry as function of the Bjorken variable xB, the Mandelstam variable t, the virtual photon four-momentum squared Q2 and the angle phi between leptonic and hadronic planes. The preliminary results are in agreement with previous measurements and with the predicted twist-2 dominance.

Study of Generalized Parton Distributions and Deeply Virtual Compton Scattering on the Nucleon with the CLAS and CLAS12 Detectors at the Jefferson Laboratory

Study of Generalized Parton Distributions and Deeply Virtual Compton Scattering on the Nucleon with the CLAS and CLAS12 Detectors at the Jefferson Laboratory PDF Author: Baptiste Guegan
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ISBN:
Category :
Languages : en
Pages : 620

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Generalized Parton Distributions and Deeply Virtual Compton Scattering on Proton at CLAS.

Generalized Parton Distributions and Deeply Virtual Compton Scattering on Proton at CLAS. PDF Author:
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Languages : en
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Two measurements of target and beam spin asymmetries for the reaction ep→ep[gamma] were performed with CLAS at Jefferson Laboratory. Polarized 5.7 GeV electrons were impinging on a longitudinally polarized ammonia and liquid hydrogen target respectively. These measurements are sensitive to Generalized Parton Distributions. Sizable sin phi azimuthal angular dependences were observed in both experiments, indicating the dominance of leading twist terms and the possibility of extracting combinations of Generalized Parton Distributions on the nucleon.

Study of Generalized Parton Distributions and Deeply Virtual Compton Scattering on the Nucleon with the CLAS and CLAS12 Detectors at the Jefferson Laboratory

Study of Generalized Parton Distributions and Deeply Virtual Compton Scattering on the Nucleon with the CLAS and CLAS12 Detectors at the Jefferson Laboratory PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 298

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Book Description
The exclusive leptoproduction of a real photon is considered to be the "cleanest" way to access the Generalized Parton Distribution (GPD). This process is called Deeply Virtual Compton Scattering (DVCS) lN 2!lN[gamma], and is sensitive to all the four GPDs. Measuring the DVCS cross section is one of the main goals of this thesis. In this thesis, we present the work performed to extract on a wide phase-space the DVCS cross-section from the JLab data at a beam energy of 6 GeV.

Deeply Virtual Compton Scattering Cross Section Measured with CLAS.

Deeply Virtual Compton Scattering Cross Section Measured with CLAS. PDF Author:
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ISBN:
Category :
Languages : en
Pages : 6

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Book Description
The Generalized Parton Distributions (GPDs) provide a new description of nucleon structure in terms of its elementary constituents, the quarks and the gluons. Including and extending the information provided by the form factors and the parton distribution functions, they describe the correlation between the transverse position and the longitudinal momentum fraction of the partons in the nucleon. Deeply Virtual Compton Scattering (DVCS), the electroproduction of a real photon on a single quark in the nucleon eN --> e'N'g, is the exclusive process most directly interpretable in terms of GPDs. A dedicated experiment to study DVCS with the CLAS detector at Jefferson Lab has been carried out using a 5.9-GeV polarized electron beam and an unpolarized hydrogen target, allowing us to collect DVCS events in the widest kinematic range ever explored in the valence region : 1.0

Deeply Virtual Compton Scattering with CLAS.

Deeply Virtual Compton Scattering with CLAS. PDF Author:
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Category :
Languages : en
Pages :

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Book Description
The beam spin asymmetries of the reaction ep -> epg in the Bjorken regime were measured over a wide kinematical domain using the CLAS detector and a new lead-tungstate calorimeter. Through the interference of the Bethe-Heitler process with Deeply Virtual Compton Scattering, those asymmetries provide constraints for the nucleon Generalized Parton Distributions models. The observed shapes are in agreement with twist-2 dominance predictions.

Deeply Virtual Compton Scattering and Generalized Parton Distributions

Deeply Virtual Compton Scattering and Generalized Parton Distributions PDF Author:
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Languages : en
Pages :

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Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. Photproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the rho vector mesons were investigated via their rare leptonic decay to e+e-. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The rho meson mass distributions were extracted for each of the targets. Statistically significant results regarding medium modification of the rho meson in the nuc.

Timelike Compton Scattering - A First Look (CLAS).

Timelike Compton Scattering - A First Look (CLAS). PDF Author:
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Languages : en
Pages :

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Book Description
A major goal of the 12 GeV upgrade at Jefferson Lab is to map out the Generalized Parton Distributions (GPDs) in the valence region. This is primarily done through Deeply Virtual Compton Scattering (DVCS), which provides the simplest and cleanest way of accessing the GPDs. However, the "inverse" process, Timelike Compton Scattering (TCS), can provide an important complement, in particular formeasuring the real part of the amplitude and understanding corrections at finite Q2. The first measurements of TCS have recently been carried out in Hall B at Jefferson Lab, using both tagged and untagged photon beams.

Generalized Parton Distributions and Deeply Virtual Compton Scattering in Color Glass Condensate Model

Generalized Parton Distributions and Deeply Virtual Compton Scattering in Color Glass Condensate Model PDF Author:
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ISBN:
Category :
Languages : en
Pages : 17

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Http://dx.doi.org/10.1140/epjc/s10052-008-0655-x Within the framework of the Color Glass Condensate model, we evaluate quark and gluon Generalized Parton Distributions (GPDs) and the cross section of Deeply Virtual Compton Scattering (DVCS) in the small-$x_{B}$ region. We demonstrate that the DVCS cross section becomes independent of energy in the limit of very small $x_{B}$, which clearly indicates saturation of the DVCS cross section. Our predictions for the GPDs and the DVCS cross section at high-energies can be tested at the future Electron-Ion Collider and in ultra-peripheral nucleus-nucleus collisions at the LHC.