What if the Higgs boson weighs 115 GeV?

If the Higgs boson indeed weighs about 114 to 115 GeV, there must be new physics beyond the Standard Model at some scale less than or similar to 10(6) GeV. The most plausible new physics is supersymmetry, which predicts a Higgs boson weighing less than or similar to 130 GeV. In the CMSSM with R and CP conservation, the existence, production and detection of a 114 or 115 GeV Higgs boson is possible if tan beta greater than or similar to 3. However, for the radiatively-corrected Higgs mass to be this large, sparticles should be relatively heavy: m(1/2) greater than or similar to 250 GeV, probably not detectable at the Tevatron collider and perhaps not at a low-energy e(+)e(-) linear collider. In much of the remaining CMSSM parameter space, neutralino-<(<tau>)over tilde> coannihilation is important for calculating the relic neutralino density, and we explore implications for the elastic neutralino-nucleon scattering cross section. (C) 2001 Elsevier Science B.V. All rights reserved.