Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Azimuthal angle dependence of di-jet production in unpolarized hadron
  scattering   We study the azimuthal angular dependence of back-to-back di-jet production
in unpolarized hadron scattering $H_A+H_B \to J_1 + J_2 +X$, arising from the
product of two Boer-Mulders functions, which describe the transverse spin
distribution of quarks inside an unpolarized hadron. We find that when the
di-jet is of two identical quarks ($J_q+J_q$) or a quark-antiquark pair
($J_q+J_{\bar{q}}$), there is a $\cos \delta \phi$ angular dependence of the
di-jet, with $\delta \phi=\phi_1-\phi_2$, and $\phi_1$ and $\phi_2$ are the
azimuthal angles of the two individual jets. In the case of $J_q+J_q$
production, we find that there is a color factor enhancement in the gluonic
cross-section, compared with the result from the standard generalized parton
model. We estimate the $\cos \delta \phi$ asymmetry of di-jet production at
RHIC, showing that the color factor enhancement in the angular dependent of
$J_q+J_q$ production will reverse the sign of the asymmetry.

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The categories of this paper are: plasm-ph
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The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: hep-lat
3
The categories of this paper are: physics