The $750\,\text{GeV}$ diphoton resonance in the light of a 2HDM with $S_3$ flavour symmetry

Abstract: Very recently we proposed a predictive 2 Higgs Doublet Model with $S_{3}$ flavour symmetry that successfully accounts for fermion masses and mixings. In this letter, motivated by the $750$ GeV Higgs diphoton resonance recently reported by the ATLAS and CMS collaborations, we modify this model by adding exotic top partners with electric charge $\frac{5}{3}$ and a electrically charged scalar singlet. These exotic top partners decay into a charged scalar singlet and the SM up type quarks, whereas the charged scalar singlet will mainly decay into SM up and down type quarks. This simple modification enables our model to successfully account for the Higgs diphoton excess at $750\,\text{GeV}$ provided that the exotic quark masses are in the range $[1,2]$ TeV, for $O(1)$ exotic quark Yukawa couplings.