Neutrinos, vacuum stability and triple Higgs coupling in SMASH

TL;DR

This paper analyzes the extended scalar sector of the SMASH model, addressing vacuum stability, neutrino masses, baryogenesis, and the triple Higgs coupling, through comprehensive one- and two-loop calculations.

Contribution

It provides a detailed phenomenological analysis of SMASH, including vacuum metastability solutions, corrections to the triple Higgs coupling, and a full two-loop renormalization group study.

Findings

Vacuum metastability can be resolved within certain SMASH parameter regions.

One-loop corrections significantly affect the triple Higgs coupling.

The model successfully explains neutrino masses, mass differences, and baryon asymmetry.

Abstract

We perform a phenomenological analysis of the observable consequences on the extended scalar sector of the SMASH (Standard Model - Axion - Seesaw - Higgs portal inflation) framework. We solve the vacuum metastability problem in a suitable region of SMASH scalar parameter spaces and discuss the one-loop correction to triple Higgs coupling $\lambda_{HHH}$. We also find that the correct neutrino masses and mass squared differences and baryonic asymmetry of the universe can arise from this model and consider running of the Yukawa couplings of the model. In fact, we perform a full two-loop renormalization group analysis of the SMASH model.