750 GeV diphotons: implications for supersymmetric unification II

Abstract: Perturbative supersymmetric gauge coupling unification is possible in six theories where complete SU (5) TeV-scale multiplets of vector matter account for the size of the reported 750 GeV diphoton resonance, interpreted as a singlet multiplet S=(s+ia)/2. One of these has a full generation of vector matter and a unified gauge coupling αG ∼ 1. The diphoton signal rate is enhanced by loops of vector squarks and sleptons, especially when the trilinear A couplings are large. If the SHuHd coupling is absent, both s and a can contribute to the resonance, which may then have a large apparent width if the mass splitting from s and a arises from loops of vector matter. The width depends sensitively on A parameters and phases of the vector squark and slepton masses. Vector quarks and/or squarks are expected to be in reach of the LHC. If the SHuHd coupling is present, a leads to a narrow diphoton resonance, while a second resonance with decays s → hh, W+W−, ZZ is likely to be discovered at future LHC runs. In some of the theories a non-standard origin or running of the soft parameters is required, for example involving conformal hidden sector interactions