Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation of a charmonium-like enhancement in the gamma gamma -->
  omega J/psi process   We report the results of a search for a charmonium-like state produced in the
process gamma gamma --> omega J/psi in the 3.9-4.2 GeV/c^2 mass region. We
observe a significant enhancement, which is well-described by a resonant shape
with mass M = (3915 +/- 3 +/- 2) MeV/c^2 and total width Gamma = (17 +/- 10 +/-
3) MeV. This enhancement may be related to one or more of the three
charmonium-like states so far reported in the 3.90-3.95 GeV/c^2 mass region.

25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
3
The categories of this paper are: physics