Gluon-induced contributions to the associated production of a Higgs and a Z-boson are calculated with NLO accuracy in QCD. They constitute a significant contribution to the cross section for this process. The perturbative correction factor (K-factor) is calculated in the limit of infinite top-quark and vanishing bottom-quark masses. The qualitative similarity of the results to the well-known ones for the gluon-fusion process gg→H allows to conclude that rescaling the LO prediction by this K-factor leads to a reliable NLO result and realistic error estimate due to missing higher-order perturbative effects. We consider the total inclusive cross section as well as a scenario with a boosted Higgs boson, where the Higgs boson's transverse momentum is restricted to values ptH>200GeV. In both cases, we find large correction factors K≈2 in most of the parameter space.
@article{arxiv.1211.5015,
title = {Gluon-induced Higgs-strahlung at next-to-leading order QCD},
author = {Lukas Altenkamp and Stefan Dittmaier and Robert V. Harlander and Heidi Rzehak and Tom J. E. Zirke},
journal= {arXiv preprint arXiv:1211.5015},
year = {2015}
}