Higgs boson pair production from gluon fusion

We calculate Higgs-boson pair production from gluon fusion at future hadron colliders. We find that the box diagram is appreciably larger then the triangle diagram for Higgs-boson masses which are experimentally accessible. This obscures the observation of the three-Higgs-boson vertex, which is present in the latter diagram.     

Production of a Higgs boson accompanied by two jets via gluon fusion

Real-emission corrections to gg-->H, which lead to H+2 jet events, are calculated at order alpha(4)(s). Contributions include top-quark triangles, boxes, and pentagon diagrams and are evaluated analytically for arbitrary top mass m(t). This new source of H+2 jet events is compared to the weak-boson fusion cross section for a range of Higgs boson masses. The heavy top-mass approximation appears to work well for intermediate Higgs-boson masses, provided that the transverse momenta of the final-state partons are smaller than the top-quark mass.