Seesaw scale in the minimal renormalizable SO(10) grand unification

Simple SO(10) Higgs models with the adjoint representation triggering the grand unified symmetry breaking, discarded long ago due to inherent tree-level tachyonic instabilities in the physically interesting scenarios, have been recently brought back to life by quantum effects. In this work we focus on the variant with 45 H⊗126 H in the Higgs sector and show that there are several regions in the parameter space of this model that can support stable unifying configurations with the B-L-breaking scale as high as 1014GeV, well above the previous generic estimates based on the minimal survival hypothesis. This admits for a renormalizable implementation of the canonical seesaw and makes the simplest potentially realistic scenario of this kind a good candidate for a minimal SO(10) grand unification. Last, but not least, this setting is likely to be extensively testable at future large-volume facilities such as Hyper-Kamiokande. © 2012 American Physical Society.