The MCPM, a two-Higgs-doublet model with maximal CP symmetry, and LHC13
  We continue our investigation of the phenomenological consequences of the MCPM for the LHC experiments. As in any two-Higgs-doublet model we have in the MCPM three neutral Higgs bosons and one charged Higgs-boson pair $H^\pm$. Here we discuss the two-photon production in proton-proton collisions. We find that in the MCPM a resonance-type structure in the $\gamma\gamma$ invariant mass distribution is predicted around twice the $H^\pm$ mass $m_{H^\pm}$ with a width $2\; \Gamma_H$ where $\Gamma_H$ is the $H^\pm$ width. If we set $m_{H^\pm} = 375$ GeV, the above resonance structure appears at 750 GeV with a width of about 45 GeV. We point out various predictions of the MCPM which follow in such a scenario and which can be checked at the LHC. 
M. Maniatis and O. Nachtmann
hep-ph