2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228834The effects of the finite top quark width in the top pair production cross section close to the threshold are discussed in this talk. We introduce a $t\bar{t}$ cross section with a cut on the invariant masses of the top and antitop that can be calculated theoretically with effective field theory (EFT) methods. The matching procedure to implement the physical phase-space boundaries in the NRQCD framework (``phase-space matching'') is briefly outlined.4 pages, 4 figures. Talk given at the 14th International QCD Conference (Montpellier 7-12th July 2008)High Energy Physics - Phenomenologytext