Speaker
Description
We present the first NNLO+PS simulation of Higgs-boson production in association with a top-quark pair ($t \bar t H$) at the LHC.
The calculation is performed within the MiNNLOps framework and combines NNLO QCD corrections with parton-shower effects in a fully differential Monte Carlo event generator (publicly available).
Since the exact two-loop amplitude is not yet known, we employ two complementary approximations based on the soft-Higgs and high-energy limits, respectively. The latter is constructed in full colour for the first time, and both approximations are combined pointwise across phase space.
After thorough validation, we present event simulations for inclusive and fiducial observables, including LO effects from Higgs decays into photons and off-shell top-quark decays. We discuss the impact of NNLO corrections and parton-shower effects on a selection of relevant observables.