Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for $t\bar{t}$ resonances in the semileptonic final state using
  pp collisions at $\sqrt s$ = 8 TeV recorded with the CMS detector   Many extensions to the Standard Model predict gauge interactions with
enhanced couplings to third generation quarks, especially the extremely heavy
top quark\cite{theoretical}. These phenomena can lead to resonances in the
production of $t\bar{t}$ pairs. In this note, a model-independent search for
the production of heavy resonances decaying into top-antitop quark pairs in the
semileptonic final state using pp collisions at $\sqrt s$ = 8 TeV recorded with
the CMS detector is presented.
  The analysis focuses on the semileptonic decay channels into electrons or
muons and covers the range of 0.5-3 TeV in the invariant mass of the $t\bar{t}$
pairs where the events present specific and different topologies. Therefore two
dedicated analyses have been performed to achieve the best sensitivity on the
whole invariant mass range: the threshold analysis (0.5-2 TeV) which is
optimized for $t\bar{t}$ production at the kinematic production threshold,
using standard top quark reconstruction techniques, and the boosted analysis
(1-3 TeV) optimized for $t\bar{t}$ produced with high Lorentz boosts, using
dedicated techniques for boosted top quarks reconstruction.
  No evidence of signal has been found. Thus the following limits at 95% C.L.
on the production of non-SM particles in specific models are set: topcolor
Z$^{\prime}$ bosons with a width of 1.2 (10) % of its mass are excluded for
masses below 2.1 TeV (up to 2.7 TeV). In addition, Kaluza-Klein excitations of
a gluon with masses below 2.5 TeV in the Randall-Sundrum model are excluded.

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The categories of this paper are: econ
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The categories of this paper are: stat
1
The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: astro-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org