Abstract
We revisit an extension of the Standard Model with Majorana fermions in adjoint representations, where triplet and octet fermions are introduced. The model provides not only a precise coupling unification but also a dark matter candidate [an triplet fermion]. In particular, we show that an octet fermion, which is required for successful unification, can be a good nonthermal source of the triplet fermion dark matter. We also show that the scenario predicts a rather short lifetime of the proton compared with the minimal supersymmetric grand unified theory, and the most parameter space can be explored by future experiments such as the Hyper-Kamiokande experiment.
- Received 8 December 2014
DOI:https://doi.org/10.1103/PhysRevD.91.075012
© 2015 American Physical Society