GUTs with dim-5 interactions: Gauge Unification and Intermediate Scales

TL;DR

This paper investigates how dimension-5 operators, potentially arising from quantum gravity or string theory, affect gauge coupling unification in GUTs, revealing that intermediate scales can be lowered to accessible TeV energies.

Contribution

It provides a comprehensive analysis of dimension-5 corrections in SU(5), SO(10), and E(6) GUTs, showing their significant impact on unification scales and intermediate particle thresholds.

Findings

Intermediate scales can be reduced to 1-10 TeV in many models.

Dimension-5 operators modify gauge coupling unification predictions.

Potential for new particles like Z' at accessible energies.

Abstract

Dimension-5 corrections to the gauge kinetic term of Grand Unified Theories (GUTs) may capture effects of quantum gravity or string compactification. Such operators modify the usual gauge coupling unification prediction in a calculable manner. Here we examine SU(5), SO(10), and E(6) GUTs in the light of all such permitted operators and calculate the impact on the intermediate scales and the unification programme. We show that in many cases at least one intermediate scale can be lowered to even 1-10 TeV, where a neutral Z' and possibly other states are expected.