We construct a supersymmetric SO(10) model with the asymptotic relation tan$\beta \simeq m_t/m_b$ automatically arising from its structure. The model retains the significant Minimal Supersymmetric Standard Model predictions for $sin^2 \theta_w$ and $\alpha_s$ and contains an automatic $Z_2$ matter parity. Proton decay through $d=5$ operators is sufficiently suppressed. It is remarkable that no global symmetries need to be imposed on the model.
Categories: hep-ph