Implementing invariant mass cuts and finite lifetime effects in top-antitop production at threshold

The 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 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.