Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Anti-charmed pentaquark $\Theta_c (3099)$ from QCD sum rules   We construct QCD sum rules for the anti-charmed pentaquark $\Theta_c (3099)$,
recently reported at HERA. The sum rules are constructed similarly with the
$\Theta^+ (1540)$ sum rules using the anti-charmed analogue of the $\Theta^+$
interpolating field. The strange quark and quark-gluon mixed condensates, which
were important in the $\Theta^+$ sum rules, are replaced by the gluon
condensates whose contribution to the OPE is suppressed due to the heavy quark
mass. Our result suggests that the parity of $\Theta_c$ is positive. We
identify the difference from the $\Theta^+$ sum rule, which leads to the
positive parity in this heavy-light pentaquark system. The obtained mass is
similar to the experimental value.

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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
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The categories of this paper are: mtrl-th
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The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
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The categories of this paper are: acc-phys
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The categories of this paper are: q-bio