Supersymmetric Higgs production in gluon fusion at next-to-leading order

TL;DR

This work computes the NLO QCD corrections to the gluon-Higgs coupling in the MSSM using an effective theory that integrates out the top quark and supersymmetric partners, and provides a Fortran routine to evaluate the Wilson coefficient C1. The authors analyze hadronic Higgs decay and production in two MSSM scenarios (including SPS1a and a gluophobic region) and find that, for most parameter choices, NLO corrections are close to the SM and typically slightly smaller (~5%). They report that cancellations between quark and squark contributions can strongly suppress the gluon-Higgs coupling and associated cross sections in certain regions, with K-factors also reduced in these zones. The paper also offers an approximate NNLO estimate by adopting SM two-loop coefficients and discusses broader applicability to related Higgs processes, accompanied by an SLHA-compatible interface for interfacing with SUSY-spectrum calculators.

Abstract

The next-to-leading order (NLO) QCD corrections to the production and decay rate of a Higgs boson are computed within the framework of the Minimal Supersymmetric Standard Model (MSSM). The calculation is based on an effective theory for light and intermediate mass Higgs bosons. We provide a Fortran routine for the numerical evaluation of the coefficient function. For most of the MSSM parameter space, the relative size of the NLO corrections is typically of the order of 5% smaller than the Standard Model value. We exemplify the numerical results for two scenarios: the benchmark point SPS1a, and a parameter region where the gluon-Higgs coupling at leading order is very small due to a cancellation of the squark and quark contributions.