  The cross section for t t-bar production in the all-jets final state is
measured in pp collisions at a centre-of-mass energy of 8 TeV at the LHC with
the CMS detector, in data corresponding to an integrated luminosity of 18.4
inverse femtobarns. The inclusive cross section is found to be 275.6 +/- 6.1
(stat) +/- 37.8 (syst) +/- 7.2 (lumi) pb. The normalized differential cross
sections are measured as a function of the top quark transverse momenta, pt,
and compared to predictions from quantum chromodynamics. The results are
reported at detector, parton, and particle levels. In all cases, the measured
top quark pt spectra are significantly softer than theoretical predictions.
