Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for Quark Contact Interactions in Dijet Angular Distributions in
  pp Collisions at sqrt(s) = 7 TeV Measured with the ATLAS Detector   Dijet angular distributions from the first LHC pp collisions at
center-of-mass energy sqrt(s) = 7 TeV have been measured with the ATLAS
detector. The dataset used for this analysis represents an integrated
luminosity of 3.1 pb-1. Dijet $\chi$ distributions and centrality ratios have
been measured up to dijet masses of 2.8 TeV, and found to be in good agreement
with Standard Model predictions. Analysis of the $\chi$ distributions excludes
quark contact interactions with a compositeness scale $\Lambda$ below 3.4 TeV,
at 95% confidence level, significantly exceeding previous limits.

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The categories of this paper are: eess
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The categories of this paper are: atom-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin