  If the lighter top squark has no kinematically allowed two-body decays that
conserve flavor, then it will form hadronic bound states. This is required in
models that are motivated by the supersymmetric little hierarchy problem and
obtain the correct thermal relic abundance of dark matter by
top-squark-mediated neutralino annihilations, or by top-squark-neutralino
co-annihilations. It is also found in models that can accommodate
electroweak-scale baryogenesis within minimal supersymmetry. I study the
prospects for detecting scalar stoponium from its diphoton decay mode at the
Large Hadron Collider, updating and correcting previous work. Under favorable
circumstances, this signal will be observable over background, enabling a
uniquely precise measurement of the superpartner masses through a narrow peak
in the diphoton invariant mass spectrum, limited by statistics and
electromagnetic calorimeter resolutions.
