Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Event shapes and subjet distributions at HERA   Recent results on subjet distributions from ZEUS are presented. The measured
normalised cross sections were used to study the pattern of parton radiation.
The comparison of the measurements with leading-logarithm parton-shower Monte
Carlo models and perturbative QCD calculations shows a good agreement between
data and predictions. Results on event-shape mean values and distributions are
also presented. These measurements were used to test the predictions of the
power-correction model for hadronisation. A universal value, within 10%, of the
effective parameter alpha_0 of the model was obtained.

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The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ph
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-th
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The categories of this paper are: nlin
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The categories of this paper are: funct-an