Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lepton Helicity Distributions in Polarized Drell-Yan Process   The lepton helicity distributions in the polarized Drell-Yan process at RHIC
energy are investigated. For the events with relatively low invariant mass of
lepton pair in which the weak interaction is negligible, only the measurement
of lepton helicity can prove the antisymmetric part of the hadronic tensor.
Therefore it might be interesting to consider the helicity distributions of
leptons to obtain more information on the structure of nucleon from the
polarized Drell-Yan process. We estimate the QCD corrections at O(alpha_s)
level to the hadronic tensor including both intermediate gamma and Z bosons. We
present the numerical analyses for different invariant masses and show that the
u (bar{u}) and d (bar{d}) quarks give different and characteristic
contributions to the lepton helicity distributions. We also estimate the lepton
helicity asymmetry for the various proton's spin configurations.

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The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph