$gg\to ZH$ : updated predictions at NLO QCD

Abstract

We present state-of-the-art predictions for the inclusive cross section of gluon-initiated $ZH$ production, following the recommendations of the LHC Higgs Working Group. In particular, we include NLO QCD corrections, where the virtual corrections are obtained from the combination of a forward expansion and a high-energy expansion, and the real corrections are exact. The expanded results for the virtual corrections are compared in detail to full numerical results. The updated predictions show a reduction of the scale uncertainties to the level of 15%, and they include an estimate of the top-mass-scheme uncertainty.

15 pages, 3 figures, contribution to the LHC Higgs Working Group Report 5; improved discussion of interplay between gluon-initiated and Drell-Yan-like contribution; results unchanged