Speaker
Description
Generalized Parton Distribution (GPDs) are universal functions which provide a comprehensive description of hadron properties in terms of quarks and gluons. Deeply Virtual Compton Scattering (DVCS) is the simplest process involving GPDs. In this talk, we will present the latest $ep \to e p \gamma$ cross sections obtained from Jlab Hall A data at three values of the Bjorken variable $x_B$. In this reaction, the photon can be emitted by a quark inside the proton (DVCS process) or by the incoming or the scattered electron (BH process). The Fourier harmonics of the $ep \to e p \gamma$ cross section can then be expressed respectively as a function of linear (from the BH-DVCS interference) and bilinear (from the DVCS process) combinations of GPD convolutions called Compton form factors (CFFs). Using the most accurate analytic expression of the $ep \to e p \gamma$ cross section we will show the first experimental extraction of all four helicity-conserving CFFs. The large number of high statistics experimental bins in the present data allows a sensitivity to some very poorly known CFFs.
| Submitted on behalf of a Collaboration? | No |
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