Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photoproduction of hidden charm pentaquark states $P_c^+(4380)$ and
  $P_c^+(4450)$   We propose to study the pentaquark candidates of $P_c^+(4380)$ and
$P_c^+(4450)$ in $J/\psi$ photoproduction and look for further experimental
evidence for their nature. Since the photoproduction process does not satisfy
the so-called "anomalous triangle singularity" condition their presence in
$J/\psi$ photoproduction would conclude that they should be genuine states and
provide further evidence for their existence.

4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom