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

TL;DR

This paper extends a 2HDM with $S_3$ symmetry to explain the 750 GeV diphoton resonance by adding exotic top partners and a charged scalar, successfully matching experimental excesses with TeV-scale new particles.

Contribution

It introduces a modified 2HDM with exotic top partners and a charged scalar to explain the 750 GeV diphoton excess, linking flavor symmetry to collider phenomenology.

Findings

Exotic top partners with charge 5/3 are introduced in the model.

The model can explain the diphoton excess with TeV-scale exotic quark masses.

Exotic quark Yukawa couplings are of order one.

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.