Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unintegrated gluon distribution from forward polarized
  $\rho$-electroproduction   We present here some arguments to support our suggestion that data on the
helicity structure for the hard exclusive electroproduction of $\rho$ mesons at
HERA (and in possible future high-energy electron-proton colliders) provide
useful information to constrain the $\kappa$-shape of the unintegrated gluon
distribution in the proton.

5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph