Oblique corrections in the Dine-Fischler-Srednicki axion model

Alisa Katanaeva,Domènec Espriu,L Bravina,Y Foka,S Kabana

doi:10.1051/epjconf/201612604024

Alisa Katanaeva, Domènec Espriu + Show 3 more

Open Access

https://doi.org/10.1051/epjconf/201612604024

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Abstract

In the Minimal Standard Model (MSM) there is no degree of freedom for dark matter. There are several extensions of the MSM introducing a new particle - an invisible axion, which can be regarded as a trustworthy candidate at least for a part of the dark matter component. However, as it is extremely weakly coupled, it cannot be directly measured at the LHC. We propose to explore the electroweak sector indirectly by considering a particular model that includes the axion and derive consequences that could be experimentally tested.We discuss the Dine-Fischler-Srednicki (DFS) model, which extends the two-Higgs doublet model with an additional Peccei-Quinn symmetry and leads to a physically acceptable axion. The non-linear parametrization of the DFS model is exploited in the generic case where all scalars except the lightest Higgs and the axion have masses at or beyond the TeV scale. We compute the oblique corrections and use their values from the electroweak experimental fits to put constraints on the mass spectrum of the DFS model.

Highlights

In this paper we reexamine the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) model
The nature of electroweak symmetry breaking keeps being an important issue in particle physics today
The Standard Model of particle physics contains a mechanism for electroweak symmetry breaking, and the discovery of the Higgs boson at the LHC proves its consistency

Summary

Introduction

In this paper we reexamine the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) model. It is the twoHiggs doublet model (2HDM) containing an additional singlet, endowed with a Peccei-Quinn (PQ) symmetry. Introduction of the PQ symmetry in the Standard Model (SM) leads to the solution of the strong CP problem but induces the necessity of two Higgs doublets and the presence of an axion. An invisible axion is a possible candidate at least for a part of the dark matter. Both these reasons, as well as the interplay between the 2HDM content and the axion, make this model interesting to study. In the same time the introduction of an axion restricts the number of possibilities, making the phenomenological consequences of the DFSZ model more rigorous

Fields and symmetries

Effective potential

Mass eigenstates

Definitions and experimental measurements

Spectrum implications

Conclusions