Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for Long-Lived Parents of Z Bosons in pbar-p Collisions at
  sqrt{s}=1.8 TeV   We search for new long-lived particles which decay to Z bosons by looking for
Z->e+e- decays with displaced vertices. We find no evidence for parent
particles of the Z with long lifetimes in 90 pb-1 of data from the CDF
experiment at Fermilab. We set a cross section limit as a function of the
lifetime of the parent particle for both a generic Z parent and a
fourth-generation, charge -1/3 quark that decays into Z+b.

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The categories of this paper are: math
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: adap-org
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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: cmp-lg
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: nlin
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The categories of this paper are: math-ph
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The categories of this paper are: q-bio
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The categories of this paper are: bayes-an