Abstract

Radiation of gluons give rise to extra jets in top quark events that can lead to complications in event reconstruction and mass measurement. In this short paper we desire to do a basic introspection of the cancellation of infrared divergence via a pedagogical treatment. We first calculate the 1-loop vertex correction to M(e +e − −→ qq¯) from virtual gluon. This computation is followed by the simplification of the three-body phase space integral. Thereafter, we compute the differential cross section from the process e +e − −→ qgq¯ to lowest order in α and αg. Following this derivation, by assigning µ to be nonzero, we reevaluate the averaged squared amplitude. Last but not the least, we complete the integral computation over Feynman parameters and finally obtain our comprehensive result