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

Abstract

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 $t\bar{t}$ 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.

Comments: 4 pages, 4 figures. Talk given at the 14th International QCD Conference (Montpellier 7-12th July 2008)