Dependence of the $t\bar{t}$ production cross section on the transverse momentum of the top quark

TL;DR

This paper measures how the production rate of top-antitop pairs varies with the top quark's transverse momentum in proton-antiproton collisions, providing data to test QCD predictions.

Contribution

It presents the first detailed differential cross section measurement of $t\bar{t}$ production as a function of top quark $p_T$ at Tevatron energies, comparing results with advanced QCD models.

Findings

Results agree with next-to-leading-order QCD calculations.

Provides validation for Monte Carlo event generators.

Enhances understanding of top quark production dynamics.

Abstract

We present a measurement of the differential cross section for $t\bar{t}$ events produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV as a function of the transverse momentum ($p_T$) of the top quark. The selected events contain a high-$p_T$ lepton ($\ell$), four or more jets, and a large imbalance in $p_T$, and correspond to 1 fb${}^{-1}$ of integrated luminosity recorded with the D0 detector. Each event must have at least one candidate for a $b$ jet. Objects in the event are associated through a constrained kinematic fit to the $t\bar{t}\to WbW\bar{b} \to \ell\nu b q\bar{q}'\bar{b}$ process. Results from 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.