  We present results from the analytic calculation of top+antitop+Higgs
hadronic production at Next-to-Leading Order in QCD interfaced with
parton-shower Monte Carlo event generators in the POWHEG BOX framework. We
consider kinematic distributions of the top quark and Higgs boson at the 8 TeV
Large Hadron Collider and study the theoretical uncertainties due to specific
choices of renormalization/factorization scales and parton-showering
algorithms, namely PYTHIA and HERWIG. The importance of spin-correlations in
the production and decay stages of a top/antitop quark is discussed on the
example of kinematic distributions of leptons originating from the top/antitop
decays. The corresponding code is now part of the public release of the POWHEG
BOX.

High Energy Physics - Phenomenology