Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cross sections for the exclusive photon electroproduction on the proton
  and Generalized Parton Distributions   Unpolarized and beam-polarized four-fold cross sections $\frac{d^4
\sigma}{dQ^2 dx_B dt d\phi}$ for the $ep\to e^\prime p^\prime \gamma$ reaction
were measured using the CLAS detector and the 5.75-GeV polarized electron beam
of the Jefferson Lab accelerator, for 110 ($Q^2,x_B,t$) bins over the widest
phase space ever explored in the valence-quark region. Several models of
Generalized Parton Distributions (GPDs) describe the data well at most of our
kinematics. This increases our confidence that we understand the GPD $H$,
expected to be the dominant contributor to these observables. Through a
leading-twist extraction of Compton Form Factors, these results reveal a
tomographic image of the nucleon.

30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio