Scenarii for interpretations of the LHC diphoton excess: two Higgs doublets and vector-like quarks and leptons

Understand

An evidence for a diphoton resonance at a mass of 750 GeV has been observed in the data collected at the LHC run at a center of mass energy of 13 TeV.

• We explore several interpretations of this signal in terms of Higgs-like resonances in a two-Higgs doublet model and its supersymmetric incarnation, in which the heavier CP-even and CP-odd states present in the model are produced in gluon fusion and decay into two photons through top quark loops.
• We show that one cannot accommodate the observed signal in the minimal versions of these models and that an additional particle content is necessary.
• We then consider the possibility that vector-like quarks or leptons strongly enhance the heavy Higgs couplings to photons and eventually gluons, without altering those of the already observed 125 GeV state.