Production of Higgs-portal singlets at hadron colliders

The differential cross sections for Higgs-portal scalar singlet production following Higgs production in proton colliders are presented, using both the gluon fusion and electroweak vector boson fusion production mechanisms. The treatment is fully partonic, using the effective vector boson approximation to obtain parton distribution functions for electroweak vector bosons. Results are presented both in semi-analytic and numerical forms. We find that missing energy signatures of low mass singlets are far more likely to be observed than those of higher mass singlets, and that any signal observed will be peaked at zero singlet momentum.