ATTENTION! We have to do a short maintenance with downtime on Wed 8 Oct 2025, 09:00 - 10:00 CEST . Please finish your work in time to prevent data loss. For further information, please have look at the IT-News article
Using the effective field theory vNRQCD one can describe heavy quark-antiquark production in electron-positron collisions close to threshold. The process is typically governed by three different scales: the mass of the heavy quarks m, their 3-momentum ~mv and their kinetic energy ~mv^2, where v is the relative velocity of the quarks. Close to the production threshold this velocity is very small (v << 1) and leads to large terms proportional to negative powers or logarithms of the velocity in quantum corrections to the total cross section. The effective theory vNRQCD allows for a systematic resummation of these terms employing a Schrödinger equation and a renormalization group with a ``subtraction velocity'' as scaling parameter, respectively. I will explain the basic ideas in the derivation of the heavy quark-antiquark resonance cross section and highlight recent improvements in the theoretical prediction. I will also discuss the application of the result in top-antitop threshold production at the ILC as well as in the bottom mass determination from nonrelativistic sum rules.
