A Generalised Missing Partner Mechanism for SU(5) GUT Inflation

TL;DR

This paper extends the Missing Partner Mechanism in SU(5) GUT models to achieve gauge coupling unification with light relics, while also addressing fermion masses and nucleon decay suppression, offering testable predictions for future colliders.

Contribution

It introduces a generalized Missing Partner Mechanism that separates electron-like and coloured states without fine-tuning, enabling realistic fermion masses and suppressed nucleon decay in SU(5) GUT Inflation.

Findings

Achieves gauge coupling unification with light relics such as weak triplet and colour octet.

Provides a mechanism for realistic fermion mass generation.

Predicts light relic states detectable at future colliders.

Abstract

We generalise the Missing Partner Mechanism to split the electron-like states from the coloured ones of vectorlike SU(5) 10-plets without fine-tuning. Together with the extra light weak doublets from the Double Missing Partner Mechanism (DMPM), this realises gauge coupling unification in the presence of a light weak triplet and colour octet, the characteristic light relics from the adjoint in SU(5) GUT Inflation models. Additionally, we show how the vectorlike 10-plets may generate realistic fermion masses while the DMPM ensures that dimension five nucleon decay is suppressed. A discovery of the light relic states at future colliders would provide a "smoking gun" signal of the scenario.