Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photo-production of the pentaquark $\Theta^{+}$ with positive and
  negative parities   We investigate the production of the pentaquark $\Theta^+$ baryon via the
$\gamma n\to K^-\Theta^+$ and $\gamma p\to \bar{K}^0 \Theta^+$ processes,
focusing on the parity of the $\Theta^+$. Using the effective Lagrangians, we
calculate the total and differential cross sections with the spin of the
$\Theta^+$ presumed to be 1/2. We employ the coupling constant of the
$KN\Theta$ vertex determined by assuming its mass and the decay width to be
$1540 {\rm MeV}$ and $15 {\rm MeV}$. That of the $K^*N\Theta$ is taken to be
about a half of the $KN\Theta$ coupling constant. We estimate the cutoff
parameter by reproducing the total cross section of the $\gamma p \to K^+
\Lambda$ reaction. It turns out that the total cross section for the $\gamma
n\to K^- \Theta^+$ process is about four times larger than that of the $\gamma
p\to\bar{K}^0\Theta^+$. We also find that the cross sections for the production
of the positive-parity $\Theta$ are about ten times as large as those for the
negative-parity ones.

29
The categories of this paper are: funct-an
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat