Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Leading asymmetries in two-hadron production in e^+e^- annihilation at
  the Z pole   We present the leading unpolarized and single spin asymmetries in inclusive
two-hadron production in electron-positron annihilation at the Z pole. The
azimuthal dependence in the unpolarized differential cross section of almost
back-to-back hadrons is a leading cos(2 phi) asymmetry, which arises solely due
to the intrinsic transverse momenta of the quarks. An extensive discussion on
how to measure this asymmetry and the accompanying time-reversal odd
fragmentation functions is given. A simple estimate indicates that the
asymmetry could be of the order of a percent.

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The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: econ
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The categories of this paper are: chem-ph