Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Observation and measurement of forward proton scattering in association
  with lepton pairs produced via the photon fusion mechanism at ATLAS   The observation of forward proton scattering in association with lepton pairs
($e^+e^-+p$ or $\mu^+\mu^-+p$) produced via photon fusion is presented. The
scattered proton is detected by the ATLAS Forward Proton spectrometer while the
leptons are reconstructed by the central ATLAS detector. Proton-proton
collision data recorded in 2017 at a center-of-mass energy of $\sqrt{s} = 13$
TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb$^{-1}$.
A total of 57 (123) candidates in the $ee+p$ ($\mu\mu+p$) final state are
selected, allowing the background-only hypothesis to be rejected with a
significance exceeding five standard deviations in each channel. Proton-tagging
techniques are introduced for cross-section measurements in the fiducial
detector acceptance, corresponding to $\sigma_{ee+p}$ = 11.0 $\pm$ 2.6 (stat.)
$\pm$ 1.2 (syst.) $\pm$ 0.3 (lumi.) fb and $\sigma_{\mu\mu+p}$ = 7.2 $\pm$ 1.6
(stat.) $\pm$ 0.9 (syst.) $\pm$ 0.2 (lumi.) fb in the dielectron and dimuon
channel, respectively.

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The categories of this paper are: chem-ph
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
9
The categories of this paper are: nlin