Virtual QCD corrections to Higgs boson plus four parton processes
R. K. Ellis, W. T. Giele, G. Zanderighi
TL;DR
The paper develops a semi-numerical approach to compute virtual one-loop QCD corrections for Higgs production in association with four partons, within an effective theory for the Higgs-gluon coupling in the large top-mass limit. It systematically analyzes all relevant Higgs+4 parton channels, decomposes amplitudes by color, and derives both divergent and finite pieces of the one-loop corrections across distinct and identical quark configurations as well as multi-gluon final states. The authors validate their method through numerical results at a representative phase-space point, demonstrate high precision, and verify scheme relations (HV vs FDH) and Ward identities, laying groundwork for a complete NLO Higgs+2-jet prediction and for extending the approach to other one-loop processes. The work provides explicit structures and counterterms necessary for renormalization and highlights the practical viability of semi-numerical loop techniques in complex QCD processes relevant to LHC Higgs analyses.
Abstract
We report on the calculation of virtual processes contributing to the production of a Higgs boson and two jets in hadron-hadron collisions. The coupling of the Higgs boson to gluons, via a virtual loop of top quarks, is treated using an effective theory, valid in the large top quark mass limit. The calculation is performed by evaluating one-loop diagrams in the effective theory. The primary method of calculation is a numerical evaluation of the virtual amplitudes as a Laurent series in $D-4$, where $D$ is the dimensionality of space-time. For the cases $H \to q\bar{q}q\bar{q}$ and $H \to q\bar{q}q'\bar{q}'$ we confirm the numerical results by an explicit analytic calculation.