Back to 1974: The $\mathcal Q$-onium

Understand

We show that the 750 GeV di-photon excess could be explained by the ${\mathcal Q}-$onium system of a new QCD-like theory with fermions vectorial under the SM.

• Beside the spin-0 di-photon singlet this scenario predicts almost degenerate colored scalars and spin-1 resonances analogous to the $J/\Psi$ in QCD.
• All these states are within the reach of the LHC.
• An apparent large width can be explained as due to production of excited states with splitting $\Delta m\sim \Gamma$.