HIGLU and HDECAY: Programs for Higgs Boson Production at the LHC and Higgs Boson Decay Widths

The total cross section for Higgs boson production via the dominant gluon fusion mechanism including NLO [two-loop] QCD corrections can be calculated numerically with the program HIGLU. The QCD corrections are included for arbitrary Higgs and quark masses and increase the cross section at the LHC by up to a factor of 2. The source code HIGLU provides the evaluation of the production of the Standard Model [SM] Higgs boson as well as the neutral Higgs bosons of the minimal supersymmetric extension [MSSM]. The program HDECAY determines the decay widths and branching ratios of the Higgs bosons within the SM and the MSSM, including the dominant higher-order corrections. The latter are dominated by QCD corrections and two-loop corrections to the couplings and Higgs masses of the MSSM. The program includes all decay modes with branching ratios larger than $10^{-4}$. Moreover, below-threshold decays with off-shell top quarks, gauge and Higgs bosons are implemented. In addition the program is able to calculate the branching ratios of the MSSM Higgs bosons into supersymmetric particles, which can be dominant.