Results are reported from a search for the pair
production of top squarks, the supersymmetric partners of
top quarks, in final states with jets and missing transverse
momentum. The data sample used in this search was collected
by the CMS detector and corresponds to an integrated luminosity
of 18.9 fb−1 of proton-proton collisions at a centreof-mass
energy of 8 TeV produced by the LHC. The search
features novel background suppression and prediction methods,
including a dedicated top quark pair reconstruction algorithm.
The data are found to be in agreement with the predicted
backgrounds. Exclusion limits are set in simplified
supersymmetry models with the top squark decaying to jets
and an undetected neutralino, either through a top quark or
through a bottom quark and chargino. Models with the top
squark decaying via a top quark are excluded for top squark
masses up to 755 GeV in the case of neutralino masses below
200 GeV. For decays via a chargino, top squark masses up
to 620 GeV are excluded, depending on the masses of the
chargino and neutralino.