Matched predictions for the bb̄H cross section at the 13 TeV LHC

We present up-to-date matched predictions for the bb̄H inclusive cross section at the LHC at √s=13 TeV. Using a previously developed method, our predictions consistently combine the complete NLO contributions that are present in the 4-flavor scheme calculation, including finite b-quark mass effects as well as top-loop induced Y_bY_t interference contributions, with the resummation of collinear logarithms of m_b/m_H as present in the 5-flavor scheme calculation up to NNLO. We provide a detailed estimate of the perturbative uncertainties of the matched result by examining its dependence on the factorization and renormalization scales, the scale of the Yukawa coupling, and also the low b-quark matching scale in the PDFs. We motivate the use of a central renormalization scale of m_H/2, which is halfway between the values typically chosen in the 4-flavor and 5-flavor scheme calculations. We evaluate the parametric uncertainties due to the PDFs and the b-quark mass, and in particular discuss how to systematically disentangle the parametric m_b dependence and the unphysical b-quark matching scale dependence. Our best prediction for the bb̄H production cross section in the Standard Model at 13 TeV and for m_H=125 GeV is σ(bb̄H)=0.52 pb [1±9.6%(perturbative) _−3.6%^+2.9%(parametric)]. We also provide predictions for a range of Higgs masses m_H∈[50,750] GeV. Our method to compute the matched prediction and to evaluate its uncertainty can be readily applied to other heavy-quark-initiated processes at the LHC.