Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for heavy particles decaying into top-quark pairs using
  lepton-plus-jets events in proton-proton collisions at $\sqrt{s} = 13$ TeV
  with the ATLAS detector   A search for new heavy particles that decay into top-quark pairs is performed
using data collected from proton-proton collisions at a centre-of-mass energy
of 13 TeV by the ATLAS detector at the Large Hadron Collider. The integrated
luminosity of the data sample is 36.1 fb$^{-1}$. Events consistent with
top-quark pair production are selected by requiring a single isolated charged
lepton, missing transverse momentum and jet activity compatible with a hadronic
top-quark decay. Jets identified as likely to contain $b$-hadrons are required
to reduce the background from other Standard Model processes. The invariant
mass spectrum of the candidate top-quark pairs is examined for excesses above
the background expectation. No significant deviations from the Standard Model
predictions are found. Exclusion limits are set on the production cross-section
times branching ratio for hypothetical $Z'$ bosons, Kaluza-Kein gluons and
Kaluza-Klein gravitons that decay into top-quark pairs.

16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol