Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exclusive photoproduction of charmonia in $\gamma p \to V p$ and $p p
  \to p V p$ reactions within $k_t$-factorization approach   The amplitude for $\gamma p \to J/\psi p$ ($\gamma p \to \psi' p$) is
calculated in a pQCD $k_{T}$-factorization approach. The total cross section
for this process is calculated for different unintegrated gluon distributions
and compared with the HERA data and the data extracted recently by the LHCb
collaboration. The amplitude for $\gamma p \to J/\psi p$ ($\gamma p \to \psi'
p$) is used to predict the cross section for exclusive photoproduction of
$J/\psi$ ($\psi'$) meson in proton-proton collisions. Compared to earlier
calculations we include both Dirac and Pauli electromagnetic form factors. The
effect of Pauli form factor is quantified. Absorption effects are taken into
account and their role is discussed in detail. Different differential
distributions e.g. in $J/\psi$ ($\psi'$) rapidity and transverse momentum are
presented and compared with existing experimental data. The UGDF with nonlinear
effects built in better describe recent experimental data of the LHCb
collaboration but no definite conclusion on onset of saturation can be drawn.
We present our results also for the Tevatron. A good agreement with the CDF
experimental data points at the midrapidity for both $J/\psi$ and $\psi'$ is
achieved.

15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio