Two-photon decays of the lightest Higgs boson of supersymmetry at the CERN LHC

We discuss the production and two-photon decay of the lightest Higgs boson (${\mathit{h}}^0$) of the minimal supersymmetric standard model at the CERN Large Hadron Collider (LHC). Since the observability of the signal is quite model dependent, we conduct a thorough scan of the parameter space of minimal supersymmetry, including experimental and theoretical constraints. If kinematically allowed, supersymmetric decay modes of ${\mathit{h}}^0$ may be important, and can even dominate all others. The coupling of ${\mathit{h}}^0$ to bb¯ can be different from that of a standard model Higgs boson; this can diminish (or enhance, but only if tanβ is very large) the ${\mathit{h}}^0$→γγ signal. We emphasize the importance of a full treatment of radiative corrections in the Higgs sector for obtaining the ${\mathit{h}}^0$bb¯ coupling. If supersymmetric particles are not too heavy, their contributions in loops can either enhance or suppress both the production cross section and the ${\mathit{h}}^0$→γγ branching fraction. We discuss the relative importance of these factors in the context of various scenarios for the discovery of supersymmetry. Even if ${\mathit{h}}^0$ is not detected at the LHC, ${\mathit{h}}^0$ may still exist in its expected mass region. © 1995 The American Physical Society.