Model-independent combination of diphoton constraints at 750 GeV

Motivated by the recent diphoton excess reported by both the ATLAS and CMS collaborations, we provide a model-independent combination of diphoton results obtained at $\sqrt{s}=8$ and 13 TeV at the LHC. We consider resonant s-channel production of a spin-0 and spin-2 particle with a mass of 750 GeV that subsequently decays to two photons. The size of the excess reported by ATLAS appears to be in slight tension with other measurements under the spin-2 particle hypothesis.
Comment: 14 pages, 6 figures, improved text, validation information added; to appear in EPJC