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 120 GeVless than or equal tom(H)less than or equal to200 GeV. For m(H)less than or equal to140 GeV we find that hadron colliders have a very limited capability to determine the Higgs boson self-coupling, lambda, 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 m(H)>140 GeV we examine ZHH and HHnu(nu) over bar production at a future e(+)e(-) linear collider with center of mass energy in the range of roots=0.5-1 TeV, 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 lambda in either the high or the low mass regions, we establish a very strong complementarity of these machines.