Phenomenological and cosmological aspects of a minimal GUT scenario

Several phenomenological and cosmological aspects of a minimal extension of the Georgi-Glashow model, where the Higgs sector is composed by 5H, 15H, and 24H, 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 τp⩽1.4×1036 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, MΦb≲106−7GeV. 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.