Unification of gauge couplings in radiative neutrino mass models

Claudia Hagedorn,Tommy Ohlsson,Michael A. Schmidt,Stella Riad

doi:10.1007/jhep09(2016)111

Abstract

We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level. Renormalization group running of gauge couplings is performed analytically and numerically at one- and two-loop order, respectively. We study three different classes of neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 $\Delta L=2$ operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino masses at one-loop level and (III) models with particles in the adjoint representation of $\mathrm{SU}(3)$. In class (I), gauge couplings unify in a few models and adding dark matter amplifies the chances for unification. In class (II), about a quarter of the models admit gauge coupling unification. In class (III), none of the models leads to gauge coupling unification. Regarding the scale of unification, we find values between $10^{14}$ GeV and $10^{16}$ GeV for models belonging to class (I) without dark matter, whereas models in class (I) with dark matter as well as models of class (II) prefer values in the range $5 \cdot 10^{10}-5 \cdot 10^{14}$ GeV.

Highlights

The Standard Model (SM) has been a great success in describing particle physics data
We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level
We study three representative classes of radiative neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 ∆L = 2 operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino masses at one-loop level and (III) models with particles in the adjoint representation of SU(3)

Summary

Introduction

The Standard Model (SM) has been a great success in describing particle physics data. It falls short in accommodating both massive neutrinos [1, 2] and dark matter (DM) [3, 4], which indicate the existence of physics beyond the SM. Without introducing new particles to the SM, neutrino masses can be encoded in the Weinberg operator [6]. Their smallness forces the scale of this operator to be close to the GUT scale, assuming no suppression of its numerical coefficient. As is well-known, the possible minimal ultraviolet (UV) completions at tree-level are the three types of the seesaw mechanism [7,8,9,10,11,12,13,14,15,16,17,18], which can be naturally obtained within a GUT

Objectives

Findings

Discussion

Conclusion