Anomaly-free chiral fermion sets and gauge coupling unification

Abstract

In this work we study which are the minimal anomaly-free chiral fermion sets, beyond the standard model, that lead to vector-like particles with respect to SU(3) and U(1) em after symmetry breaking. We focus on fermion multiplets with SU(3) and SU(2) dimensions less than or equal to 10 and 5, respectively. Furthermore, we study whether the addition of such chiral fermions allows for gauge coupling unification, at some high scale compatible with proton decay limits.