Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First measurement of the cross section for top quark pair production
  with additional charm jets using dileptonic final states in pp collisions at
  $\sqrt{s} = $ 13 TeV   The first measurement of the inclusive cross section for top quark pairs
($\mathrm{t\bar{t}}$) produced in association with two additional charm jets is
presented. The analysis uses the dileptonic final states of $\mathrm{t\bar{t}}$
events produced in proton-proton collisions at a centre-of-mass energy of 13
TeV. The data correspond to an integrated luminosity of 41.5 fb$^{-1}$,
recorded by the CMS experiment at the LHC. A new charm jet identification
algorithm provides input to a neural network that is trained to distinguish
among $\mathrm{t\bar{t}}$ events with two additional charm
($\mathrm{t\bar{t}c\bar{c}}$), bottom ($\mathrm{t\bar{t}b\bar{b}}$), and
light-flavour or gluon ($\mathrm{t\bar{t}LL}$) jets. By means of a template
fitting procedure, the inclusive $\mathrm{t\bar{t}c\bar{c}}$,
$\mathrm{t\bar{t}b\bar{b}}$, and $\mathrm{t\bar{t}LL}$ cross sections are
simultaneously measured, together with their ratios to the inclusive
$\mathrm{t\bar{t}}$ + two jets cross section. This provides measurements of the
$\mathrm{t\bar{t}c\bar{c}}$ and $\mathrm{t\bar{t}b\bar{b}}$ cross sections of
10.1 $\pm$ 1.2 (stat) $\pm$ 1.4 (syst) pb and 4.54 $\pm$ 0.35 (stat) $\pm$ 0.56
(syst) pb, respectively, in the full phase space. The results are compared and
found to be consistent with predictions from two different matrix element
generators with next-to-leading order accuracy in quantum chromodynamics,
interfaced with a parton shower simulation.

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The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: q-alg
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-th
1
The categories of this paper are: cs
3
The categories of this paper are: physics
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: patt-sol
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-th