The minimal scalar-vectorlike top interpretation of the diphoton excess

A resonance near 750GeV has been observed at both ATLAS and CMS experiments in the diphoton channel. We propose an interpretation based on a simplified model, in which a 750GeV scalar singlet and compressed vectorlike tops are introduced. At the LHC, the new scalar is produced through gluon fusion, and subsequently decays to the diphoton final state, with the new vectorlike quarks running in the loop diagram. We find that the compressed tops with their masses around 400-500GeV and couplings around 0.5-1.5 could explain the diphoton excess, while keeping signals of other channels under the current LHC search limits. We also comment on other potential signatures of this vectorlike top model.