NLO QCD predictions for $t\bar{t}b\bar{b}$ production in association with a light jet at the LHC

Understand

Theoretical predictions for ttbb production are of crucial importance for ttH measurements in the H->bb channel at the LHC.

• To address the large uncertainties associated with the modelling of extra QCD radiation in ttbb events, in this paper we present a calculation of pp->ttbbj at NLO QCD.
• The behaviour of NLO corrections is analysed in a variety of observables, and to assess theoretical uncertainties we use factor-two rescalings as well as different dynamic scales.
• In this context, we propose a systematic alignment of dynamic scales that makes it possible to disentangle normalisation and shape uncertainties in a transparent way.