Accidental symmetries in the scalar potential of the Standard Model extended with two Higgs triplets

TL;DR

This paper investigates the accidental symmetries of the scalar potential in the two-Higgs-triplet model, revealing a maximal symmetry group of SO(4) and identifying eight distinct accidental symmetries, which could impact neutrino mass and matter-antimatter asymmetry explanations.

Contribution

It provides a group-theoretical analysis of the scalar potential symmetries in the 2HTM, identifying the maximal symmetry group and classifying all accidental symmetries.

Findings

Maximal symmetry group is SO(4).

Eight distinct accidental symmetries identified.

Group-theoretical approach used for analysis.

Abstract

The two-Higgs-triplet model (2HTM) provides us with an attractive way to simultaneously account for tiny neutrino masses and the observed matter-antimatter asymmetry in our Universe. In this talk, we study the accidental symmetries of the scalar potential in the 2HTM using the bilinear-field formalism. Based on the group-theoretical arguments, we prove that the maximal symmetry group is ${\rm SO(4)}$. We carefully analyze all the subgroups of ${\rm SO(4)}$, and find that there are eight distinct kinds of accidental symmetries in the scalar potential of the 2HTM.