Top quark pair + jet production at next-to-leading order: NLO QCD corrections to gg -> t tbar g

The reaction pp/pbar p -> t tbar jet+X is an important background process for Higgs boson searches in the mass range below 200 GeV. Apart from that it is also an ideal laboratory for precision measurements in the top quark sector. Both applications require a solid theoretical prediction, which can be achieved only through a full next-to-leading order (NLO) calculation. In this work we describe the NLO computation of the subprocess gg -> t tbar g.