Implications of a dark grand unification

TL;DR

This paper explores how dark matter and neutrino mass can be explained through residual theories derived from dark grand unification, proposing novel models that unify these phenomena within extended gauge frameworks.

Contribution

It introduces new residual low-energy theories from dark grand unification, including a matter-stabilizing 3-3-1-1 model embedded in trinification, and explains neutrino masses via combined seesaw and scotogenic mechanisms.

Findings

Proposes a matter parity within an $E_6$ chain stabilizing dark matter.

Develops a novel family-universal 3-3-1-1 model embedded in trinification.

Shows neutrino masses arise naturally from combined seesaw and scotogenic schemes.

Abstract

Given that dark matter and normal matter are nontrivially unified in a grand unified theory, called dark grand unification, we derive novel residual theories at low energy explaining dark matter and neutrino mass. The first chain of which is $E_6\to SU(3)_C\otimes SU(3)_L\otimes SU(3)_R$, which contains a matter parity by itself stabilizing a dark matter candidate and producing neutrino mass via a seesaw. The second chain is $\mathrm{Trinification}\to SU(3)_C \otimes SU(3)_L\otimes U(1)_X\otimes U(1)_N$, which results in a novel family-universal 3-3-1-1 model, opposite to the normal 3-3-1-1 (or corresponding 3-3-1) model. Surprisingly, it is a variant of both minimal 3-3-1 model and 3-3-1 model with right-handed neutrinos since both $e_R$ and $\nu_R$ are located at the bottoms of lepton triplets. Since this universal 3-3-1-1 model is properly embedded in the trinification, the above matter parity works governing dark matter stability as well as suppressing unwanted fermion mixings. Further, neutrino masses are naturally generated by a canonical seesaw combined with a scotogenic scheme.