Speaker
Description
I present full off-shell predictions of the production of a top quark pair in association with flavoured jets in the $2\ell$ decay channel at the LHC. Thereby reporting results of the NLO QCD computation for the $pp\to e^+ \nu_e \, \mu^- \bar{\nu}_\mu + nb +X$ process, where $n=3,4$. This calculation includes all resonant and non-resonant diagrams as well as interferences and finite width effects of the top quark and $W$ boson. For the calculation with $n=4$ we compare our predictions in the 5- and 4-flavour schemes. The calculation for $n=3$ is only provided in the 4FS. The modelling of the $b$-jets in these phase-space regions is studied in detail. These predictions are relevant for the $pp\to t\bar{t}H(H\to b\bar{b})$ process, for which the QCD $pp \to t\bar{t}b\bar{b}$ process is an important irreducible background.