Production of t(t)over-barb(b)over-bar at the LHC at NLO QCD

作者：Bredenstein A^*; Denner A; Dittmaier S; Pozzorini S

来源：10th DESY Workshop on Elementary Particle Theory, 2010-04-25 to 2010-04-30.

DOI：10.1016/j.nuclphysbps.2010.08.023

We summarise predictions for t (t) over barb (b) over bar production at the LHC in next-to-leading order QCD. The precise description of this background process is a prerequisite to observe associated t (t) over barH production in the H -> b (b) over bar decay channel. The one-loop amplitudes are computed using Feynman diagrams and numerical tensor reduction. This approach provides very high numerical stability and CPU efficiency. We find that the scale choice adopted in ATLAS simulations underestimates the t (t) over barb (b) over bar background by a factor two and introduce a new dynamical scale that stabilises the perturbative predictions. In the regime of highly boosted Higgs bosons, which offers better perspectives to observe the t (t) over barH(H -> b (b) over bar) signal, the corrections induce significant distortions in the kinematic distributions.