Phenomenological and cosmological aspects of a minimal GUT scenario

Abstract

Several phenomenological and cosmological aspects of a minimal extension of the Georgi–Glashow model, where the Higgs sector is composed by 5 H , 15 H , and 24 H , are studied. It is shown that the constraints coming from the unification of gauge interactions up to two-loop level predict light scalar leptoquarks. In this GUT scenario, the upper bound on the total proton decay lifetime is τ p ⩽ 1.4 × 10 36 years. The possibility to explain the matter–antimatter asymmetry in the universe through the decays of SU ( 2 ) L scalar triplets is also studied in the simplest extension of our GUT scenario, which consists on the addition of right-handed neutrinos. We find that a successful triplet seesaw leptogenesis implies an upper bound on the scalar leptoquark mass, M Φ b ≲ 10 6 − 7 GeV . We conclude that this GUT scenario can be tested at the next generation of proton decay experiments and future colliders through the production of scalar leptoquarks.