Color-octet scalar effects on Higgs boson production in gluon fusion

TL;DR

This paper calculates advanced QCD corrections for Higgs production via gluon fusion in models with color-octet scalars, revealing significant potential increases in production rates and providing constraints on new physics parameters.

Contribution

It provides the first NNLO QCD correction calculation for Higgs production with color-octet scalars and analyzes their impact on collider phenomenology.

Findings

Higgs production rate can increase by more than a factor of two.

Allowed scalar parameter regions are constrained by Tevatron data.

The calculation includes a novel treatment of quartic scalar interactions at NNLO.

Abstract

We compute the next-to-next-to-leading order QCD corrections to the gluon-fusion production of a Higgs boson in models with massive color-octet scalars in the ${\bf (8,1)_0}$ representation using an effective-theory approach. We derive a compact analytic expression for the relevant Wilson coefficient, and explain an interesting technical aspect of the calculation that requires inclusion of the quartic-scalar interactions at next-to-next-to-leading order. We perform a renormalization-group analysis of the scalar couplings to derive the allowed regions of parameter space, and present phenomenological results for both the Tevatron and the LHC. The modifications of the Higgs production cross section are large at both colliders, and can increase the Standard Model rate by more than a factor of two in allowed regions of parameter space. We estimate that stringent constraints on the color-octet scalar parameters can be obtained using the Tevatron exclusion limit on Higgs production.