Flavor anomalies, the 750 GeV diphoton excess, and a dark matter candidate

We argue that the diphoton excess recently reported by ATLAS and CMS can be explained, along with several anomalies seen in the flavor sector, in models where a Standard Model singlet scalar resonance with mass M-S approximate to 750 GeV is produced in gluon fusion via loops containing a scalar color-triplet leptoquark phi. For a leptoquark mass M-phi less than or similar to 1 TeV, the production cross section is naturally in the 10 fb range. A large S -> gamma gamma branching ratio can be obtained by coupling the scalar S to new color-singlet fermions chi with electroweak scale masses, which can be part of an SU(2)(L) multiplet, whose neutral component has the right mass and quantum numbers to be a dark matter candidate. Our model reveals a connection between flavor anomalies, the nature of dark matter and a new scalar, which acts as a mediator to the dark sector. The loop-mediated decay S -> tau(+)tau(-) could be a striking signature of this model.