Search for natural supersymmetry in events with top quark pairs and photons in pp collisions at $\sqrt{s}=8~\mathrm{TeV}$

We present a search for a natural gauge-mediated supersymmetry breaking scenario with the top squark as the lightest squark and the gravitino as the lightest supersymmetric particle. The strong production of top squark pairs and their decays would produce events with pairs of top quarks and neutralinos, with each neutralino decaying to a photon and a gravitino. This search is performed with the CMS experiment using pp collision data at $\sqrt{s}=8~\mathrm{TeV}$, corresponding to an integrated luminosity of $19.7~\mathrm{fb}^{-1}$, in the electron + jets and muon + jets channel, requiring one or two photons in the final state. We compare the missing transverse momentum of these events against the expected spectrum of standard model processes. No excess of events is observed beyond background predictions and the result of the search is interpreted in the context of a general model of gauge-mediated supersymmetry breaking deriving limits on the mass of top squarks up to 750 GeV.