NLO matching for ttbb production with massive b-quarks

Abstract

Theoretical uncertainties in the simulation of ttbb production represent one of the main obstacles that still hamper the observation of Higgs-boson production in association with top-quark pairs in the H->bb channel. In this letter we present a next-to-leading order (NLO) simulation of ttbb production with massive b-quarks matched to the Sherpa parton shower. This allows one to extend NLO predictions to arbitrary ttbb kinematics, including the case where one or both b-jets arise from collinear g->bb splittings. We find that this splitting mechanism plays an important role for the ttH(bb) analysis.

4 pages, 3 figures. v2: b-jet momenta replaced by b-quark momenta in the dynamical QCD scale; related technical cut removed; numerical results updated accordingly and conclusions unchanged. References and various comments on the resummation of b-mass logarithms and on the consistency of double-splitting contributions added. Version to appear in Phys. Lett B