Models of 750 GeV quarkonium and the LHC excesses

Understand

We investigate models involving a vector-like quark X, which forms a 750 GeV bound state and reproduces the observed diphoton signals at the LHC, in connection with other excesses in the LHC data.

• An exotic hypercharge of -4/3 is required to fit the signal cross section, which indicates that there is additional particle(s) that mediates the decay of X in the full theory.
• We find that, introducing an SU(2) doublet vector-like quark of mass around 600 GeV in our UV-complete framework can accommodate not only the diphoton but also the on-Z excess (and potentially a slight excess in the monojet events).
• Our models also include a dark matter candidate.