Deeply Virtual Compton Scattering on Longitudinally Polarized Protons at CLAS
Erin Seder
University of Connecticut at Storrs and Jefferson Laboratory
Vendredi 25/04/2014, 11:00-12:00
Bat 703, p 45, CEA Saclay, Orme des Merisiers

Deeply Virtual Compton Scattering (DVCS), where a high energy electron

scatters off an individual parton in a nucleon which emits a high-energy

photon as a result, is the simplest process to access Generalized Parton

Distributions (GPDs) of the nucleon. The DVCS process interferes at the

amplitude level with the Bethe-Heitler (BH) process, where the real

photon is emitted either by the incoming or the scattered electron. The

resulting DVCS-BH interference terms are connected to linear

combinations of GPDs and are accessible through polarization observables

including spin asymmetry measurements. The sensitivity to the four

leading-order twist-2 GPDs depends on the polarization

observable extracted, making different polarization observable

measurements complementary in the effort of GPD extraction.

 

This talk focuses on the work and results obtained at Jefferson Lab

using a 6 GeV polarized electron beam, longitudinally polarized (via

Dynamic Nuclear Polarization) proton target and the CEBAF Large

Acceptance Spectrometer equipped with an additional inner calorimeter

for enhanced low angle photon coverage. The high statistics collected

allow for detailed studies of the Q2, xB and t dependencies of 3

spin-asymmetries (beam-spin, target-spin, and double-spin) over a wide

range of kinematics. Preliminary results for the 3 spin-asymmetries will

be shown.


Contact : Stephane PLATCHKOV

 

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