Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for WW production from double-parton interactions in
  proton-proton collisions at $\sqrt{s} =$ 13 TeV   A search for WW production from double-parton scattering processes using
same-charge electron-muon and dimuon events is reported, based on proton-proton
collision data collected at a center-of-mass energy of 13 TeV. The analyzed
data set corresponds to an integrated luminosity of 77.4 fb$^{-1}$, collected
using the CMS detector at the LHC in 2016 and 2017. Multivariate classifiers
are used to discriminate between the signal and the dominant background
processes. A maximum likelihood fit is performed to extract the signal cross
section. This leads to the first evidence for WW production via double-parton
scattering, with a significance of 3.9 standard deviations. The measured
inclusive cross section is 1.41 $\pm$ 0.28 (stat) $\pm$ 0.28 (syst) pb.

24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph