Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of double parton scattering using W + 2-jet events in
  proton-proton collisions at sqrt(s) = 7 TeV   Double parton scattering is investigated in proton-proton collisions at
sqrt(s) = 7 TeV where the final state includes a W boson, which decays into a
muon and a neutrino, and two jets. The data sample corresponds to an integrated
luminosity of 5 inverse femtobarns, collected with the CMS detector at the LHC.
Observables sensitive to double parton scattering are investigated after being
corrected for detector effects and selection efficiencies. The fraction of W +
2-jet events due to double parton scattering is measured to be 0.055 +/- 0.002
(stat.) +/- 0.014 (syst.). The effective cross section, sigma[eff],
characterizing the effective transverse area of hard partonic interactions in
collisions between protons is measured to be 20.7 +/- 0.8 (stat.) +/- 6.6
(syst.) mb.

12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat