Proposed new signal for scalar top-squark bound-state production

We study the production and decay of a scalar (t${\mathrm{̃}}_1$t${\mathrm{̃}}_1^{\mathrm{*}}$) bound state ${\mathrm{\sigma }}_{\mathit{t}\mathrm{̃}1}$ at hadron supercolliders, where t${\mathrm{̃}}_1$ is the lighter scalar top eigenstate. If t${\mathrm{̃}}_1$ has no tree-level 2-body decays, the dominant decay modes of ${\mathrm{\sigma }}_{\mathit{t}\mathrm{̃}1}$ are gg or, if ${\mathit{m}}_{\mathit{h}}$<${\mathit{m}}_{\mathit{t}\mathrm{̃}\mathit{i}}$≪${\mathit{m}}_{\mathit{t}\mathrm{̃}2}$, a pair of light scalar Higgs bosons h. Nevertheless, the branching ratio into two photons is often large enough to yield a detectable signal.