Examining the Higgs boson potential at lepton and hadron colliders: A comparative analysis

We investigate inclusive standard model Higgs boson pair production at lepton and hadron colliders for Higgs boson masses in the range 120GeV<~mH<~200GeV. For mH<~140GeV we find that hadron colliders have a very limited capability to determine the Higgs boson self-coupling, λ, due to an overwhelming background. We also find that, in this mass range, supersymmetric Higgs boson pairs may be observable at the CERN LHC, but a measurement of the self-coupling will not be possible. For mH>140GeV we examine ZHH and HHνν production at a future e⁺e^- linear collider with center of mass energy in the range of √s=0.5-1TeV, and find that this is likely to be equally difficult. Combining our results with those of previous literature, which has demonstrated the capability of hadron and lepton machines to determine λ in either the high or the low mass regions, we establish a very strong complementarity of these machines.