A simple SU(5) model with unification near the Planck scale

TL;DR

This paper presents a minimal SU(5) grand unified model with an extra Dirac multiplet that achieves gauge coupling unification near the Planck scale, featuring a dark matter candidate and satisfying anomaly constraints.

Contribution

It introduces a simple SU(5) model with an additional Dirac multiplet in the 24 representation, enabling unification close to the Planck scale and compatibility with anomaly conditions.

Findings

Unification occurs near the Planck scale.

The model predicts a light triplet with a neutral component as dark matter.

It satisfies the anomaly condition requiring fermion numbers to be multiples of 16.

Abstract

We study unification in the SU(5) model with an extra Dirac multiplet in the ${\bf 24}$ representation. After spontaneous symmetry breaking we have at low energies a singlet, a colorless triplet and a neutral color-octet. All other particles can be taken at the unification scale. This combination leads to a unification very near the Planck scale. The triplet is light, its neutral component is a dark matter candidate. The model is in agreement with a recently derived anomaly condition, that implies that the number of (Weyl)-fermions has to be a multiple of 16.