A grand unified model with $M_G\sim M_{string}$ and $M_I\sim 10^{12}$ GeV

Abstract

We present a model based on the gauge group SU(2)_L\times SU(2)_R \times SU(4)_C with gauge couplings that are found to be unified at a scale near the string unification scale. This model breaks to the MSSM at an intermediate scale which is instrumental in producing a neutrino in a mass range that can serve as hot dark matter and can also solve the strong CP problem via a harmless invisible axion.

Comments: 4 pages, LaTex, uses sprocl.sty. To appear in the proceedings of 1996 Annual Divisional Meeting (DPF96) of the Division of Particles and Fields of the American Physical Society, Minneapolis, MN, 10-15 Aug 1996. No figures