Deeply Virtual Compton Scattering on Longitudinally Polarized Protons and Neutrons at CLAS.

Deeply Virtual Compton Scattering on Longitudinally Polarized Protons and Neutrons at CLAS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

Deeply Virtual Compton Scattering on Longitudinally Polarized Protons and Neutrons at CLAS.

Deeply Virtual Compton Scattering on Longitudinally Polarized Protons and Neutrons at CLAS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

Measurement of Deeply Virtual Compton Scattering with a Polarized Proton Target

Measurement of Deeply Virtual Compton Scattering with a Polarized Proton Target PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
The longitudinal target-spin asymmetry A{sub UL} for the exclusive electroproduction of high energy photons was measured for the first time in p(e, e'p/gamma). The data have been accumulated at Jefferson Lab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the Deeply Virtual Compton Scattering and Bethe-Heitler processes. The amplitude of the sin[phi] moment is 0.252 +/- 0.042(stat) +/- 0.020(sys). Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H-tilde.

Single and Double Spin Asymmetries for Deeply Virtual Compton Scattering Measured with CLAS and a Longitudinally Polarized Proton Target

Single and Double Spin Asymmetries for Deeply Virtual Compton Scattering Measured with CLAS and a Longitudinally Polarized Proton Target PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton e→p→e'p'[gamma] are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized 14NH3 target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. As a result, the measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the H and H~ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton.

Deeply Virtual Compton Scattering at JLab Hall A.

Deeply Virtual Compton Scattering at JLab Hall A. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
The deeply virtual Compton scattering reaction has been investigated in the Hall A of the Jefferson Laboratory by measuring longitudinally polarized (e, e'gamma) cross sections, in the valence quark region, for protons and neutrons. In the proton channel, experimental results strongly support the factorization of the cross section at Q2 as low as 2 GeV2, opening the path to systematic measurements of generalized parton distributions (GPDs). In the neutron case, preliminary data show sensitivity to the angular momentum of quarks.

Generalized Parton Distributions from Deep Virtual Compton Scattering at CLAS.

Generalized Parton Distributions from Deep Virtual Compton Scattering at CLAS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7

Get Book Here

Book Description
Here, we have analyzed the beam spin asymmetry and the longitudinally polarized target spin asymmetry of the Deep Virtual Compton Scattering process, recently measured by the Jefferson Lab CLAS collaboration. Our aim is to extract information about the Generalized Parton Distributions of the proton. By fitting these data, in a largely model-independent procedure, we are able to extract numerical values for the two Compton Form Factors $H_{Im}$ and $\tilde{H}_{Im}$ with uncertainties, in average, of the order of 30%.

Deeply Virtual Compton Scattering Off Longitudinally Polarised Protons at HERMES

Deeply Virtual Compton Scattering Off Longitudinally Polarised Protons at HERMES PDF Author: David F. Mahon
Publisher:
ISBN:
Category : Compton effect
Languages : en
Pages : 133

Get Book Here

Book Description


Target-spin Asymmetry Measurements for Deeply Virtual Compton Scattering on Longitudinally Polarized Protons

Target-spin Asymmetry Measurements for Deeply Virtual Compton Scattering on Longitudinally Polarized Protons PDF Author: Erin E. Seder
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description


First Measurement of Deeply Virtual Compton Scattering with Polarized Proton Target

First Measurement of Deeply Virtual Compton Scattering with Polarized Proton Target PDF Author: Shifeng Chen
Publisher:
ISBN:
Category : Hadrons
Languages : en
Pages :

Get Book Here

Book Description


Deeply Virtual Compton Scattering Cross Section Measured with CLAS.

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

Get Book Here

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

Longitudinal Target-spin Asymmetries for Deeply Virtual Compton Scattering

Longitudinal Target-spin Asymmetries for Deeply Virtual Compton Scattering PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description
A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep → e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and [Phi], for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. In conclusion, these results bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.