Dependence of the tt¯ production cross section on the transverse momentum of the top quark

We present a measurement of the differential cross section for tt¯ events produced in pp¯ collisions at s=1.96 TeV as a function of the transverse momentum (pT) of the top quark. The selected events contain a high-pT lepton (ℓ), a large imbalance in pT, four or more jets with at least one candidate for a b jet, and correspond to 1 fb−1 of integrated luminosity recorded with the D0 detector. Objects in the event are associated through a constrained kinematic fit to the tt¯→WbWb¯→ℓνbqq¯′b¯ process. Results from next and next-to-next-to-leading-order perturbative QCD calculations agree with the measured differential cross section. Comparisons are also provided to predictions from Monte Carlo event generators using QCD calculations at different levels of precision.