This article describes the code SusHi (for "Supersymmetric Higgs") [1] which calculates the cross sections pp/pp → φ + X in gluon fusion and bottom-quark annihilation in the SM and the MSSM, where φ is any of the neutral Higgs bosons within these models. Apart from inclusive cross sections up to NNLO QCD, differential cross sections with respect to the Higgs transverse momentum p T and (pseudo-)rapidity y(η) can be calculated through NLO QCD. In the case of gluon fusion, SusHi contains NLO QCD contributions from the third family of quarks and squarks, NNLO corrections due to top-quarks, approximate NNLO corrections due to top-squarks, and electro-weak effects. It supports various renormalization schemes for the sbottom sector and the bottom Yukawa coupling, as well as resummation effects of higher order tan β-enhanced sbottom contributions. SusHi provides a link to FeynHiggs for the calculation of the Higgs masses.

The inclusive Higgs production cross section from gluon fusion is calculated through NNLO QCD, including its top quark mass dependence. This is achieved through a matching of the 1/M t expansion of the partonic cross sections to the exact large-ŝ limits which are derived from k T -factorization. The accuracy of this procedure is estimated to be better than 1% for the hadronic cross section. The final result is shown to be within 1% of the commonly used effective theory approach, thus confirming earlier findings.

Version 1.6.0 of the code SusHi is presented. Concerning inclusive CP-even Higgs production in gluon fusion, the following new features with respect to previous versions have been implemented: expansion of the partonic cross section in the soft limit, i.e. around x = M 2 H /ŝ → 1; N 3 LO QCD corrections in terms of the soft expansion; top-quark mass suppressed terms through NNLO; matching to the cross section at x → 0 through N 3 LO. For CP-even and -odd scalars, an efficient evaluation of the renormalization-scale dependence is included, and effects of dimension-5 operators can be studied, which we demonstrate for the SM Higgs boson and for a CP-even scalar with a mass of 750 GeV. In addition, as a generalization of the previously available bb → H cross section, SusHi 1.6.0 provides the cross section for charged and neutral Higgs production in the annihilation of arbitrary heavy quarks. At fixed order in perturbation theory, SusHi thus allows to obtain Higgs cross-section predictions in different models to the highest precision known today. For the SM Higgs boson of M H = 125 GeV, SusHi yields 48.28 pb for the gluon-fusion cross section at the LHC at 13 TeV. Simultaneously, SusHi provides the renormalization-scale uncertainty of ±1.97 pb. Compared to version 1.0.0 the newest SusHi version 1.6.0 now supports the 2-Higgs-DoubletModel (2HDM) and the next-to-minimal supersymmetric standard model (NMSSM). The effects of dimension-5 operators in the calculation of the gluon-fusion cross section can be studied. It allows to calculate the Higgs production cross section from the annihilation of heavy quarks and includes various new features which improve the gluon-fusion cross-section prediction and the associated uncertainty estimate. Links to external codes 2HDMC, MoRe-SusHi and MadGraph5 aMC@NLO can be established. Summary of revisions:Inclusion of 2HDM, NMSSM; Improvements in the prediction of the gluon-fusion cross section: Topquark mass terms up to next-to-next-to leading order, soft expansion and next-to-next-to-next-to leading order corrections in the heavy top-quark effective theory, top squark corrections up to next-to-next-to leading order; dimension-5 operators; analytic determination of the renormalization scale dependence. Inclusion of heavy-quark annihilation cross sections. Link to MoRe-SusHi for the calculation of resummed transverse-momentum distributions. Nature of problem: Calculation of inclusive and exclusive Higgs production cross sections in gluon fusion and heavyquark annihilation in the SM and extended Higgs sectors through next-to-leading order QCD, including (next-to-)next-to-next-to-leading order top-(s)quark contributions and electroweak effects. Solution method: Numerical Monte Carlo integration. References: http://sushi.hepforge.org

The resummed transverse momentum distribution of the Higgs boson in gluon fusion through LO+NLL for small transverse momenta is considered, where the Higgs is produced through a top-and bottom-quark loop. We study the mass effects with respect to the infinite top-mass approach. The top-mass effects are small and the heavy-top limit is valid to better than 4% as long as the Higgs' transverse momentum stays below 150 GeV. When the bottom loop is considered as well, the discrepancy reaches up to about 10%. We conclude that bottom-mass effects cannot be included in a reasonable manner by a naive reweighting procedure in the heavy-top limit. We compare our results to an earlier, alternative approach based on POWHEG.

Abstract:The resummed transverse momentum distribution of supersymmetric Higgs bosons produced through gluon fusion at NLO + NLL is presented, including the exact quark and squark mass dependences. Considering various MSSM scenarios, we compare our results to previous ones within the POWHEG approach. We analyze the impact of the bottom loop which becomes the dominant contribution to the gluon fusion cross section for a wide range of the parameter space for the pseudo-scalar and heavy Higgs.