Observability of the lightest CMSSM Higgs boson at hadron colliders

We discuss the observability of the lightest neutral Higgs boson in the constrained MSSM (CMSSM), with universal soft supersymmetry-breaking parameters, at hadron colliders such as the Tevatron and the LHC. We take account of the constraints on parameter space provided by LEP, the measured rate of b→sγ decay, the cosmological relic density Ωχh2, and the recent measurement of gμ−2. We normalize products of the expected CMSSM Higgs production cross sections and decay branching ratios σ×B relative to those expected for a Standard Model Higgs boson of the same mass. In the h→γγ channel, we find that [σ(gg→h)×B(h→γγ)]CMSSM≳0.85×[σ(gg→h)×B(h→γγ)]SM. In the W±/t̄t+h,h→b̄b channels, we find that [σ(W±/t̄t+h)×B(h→b̄b)]CMSSM∼1.05×[σ(W±/t̄t+h)×B(h→b̄b)]SM. We conclude that the lightest CMSSM Higgs boson should be almost as easy to see as the Standard Model Higgs boson: in particular, it should be discoverable with about 15 fb−1 of luminosity at the Tevatron or 10 fb−1 of luminosity at the LHC.