Resonant Diphoton Phenomenology Simplified
  A framework is proposed to describe resonant diphoton phenomenology at hadron colliders in full generality. It can be employed for a comprehensive model-independent interpretation of the experimental data. Within the general framework, few benchmark scenarios are defined as representative of the various phenomenological options and/or of motivated new physics scenarios. Their usage is illustrated by performing a characterization of the 750 GeV excess, based on a recast of available experimental results.   We also perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions. These include the spin J of the new particle and its dominant production mode. Partial information on its CP-parity can also be obtained, but only for $J\geq2$. The complete determination of the resonance CP properties requires studying the pattern of the initial state radiation that accompanies the resonant diphoton production. 
Giuliano Panico, Luca Vecchi and Andrea Wulzer
hep-ph hep-ex