Natural Unification with a Supersymmetric SO(10)$_{GUT} \:\times$   SO(6)$_H$ Gauge Theory
  We propose a unified model of elementary particles based on a supersymmetric SO(10)$_{GUT} \:\times$ SO(6)$_H$ gauge theory. This model completely achieves natural unification of the strong and electroweak interactions without any fine-tunings. 
T. Hotta, K.-I. Izawa. and T. Yanagida