  The top-antitop quark (t t-bar) production cross section is measured in
proton-proton collisions at sqrt(s) = 8 TeV with the CMS experiment at the LHC,
using a data sample corresponding to an integrated luminosity of 5.3 inverse
femtobarns. The measurement is performed by analysing events with a pair of
electrons or muons, or one electron and one muon, and at least two jets, one of
which is identified as originating from hadronisation of a bottom quark. The
measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for
an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the
standard model.
