Electroweak unification is obtained in an SU(4) model with ${\mathrm{SU}}_L\mathrm{}\left(2\right)\mathrm{}\times {\mathrm{SU}}_R\mathrm{}\left(2\right)\mathrm{}\times \mathrm{U}\mathrm{}\left(1\right)\mathrm{}$ as its subgroup and ${sin}^2{\theta }_W^0=\frac{1}{4}$ in the symmetry limit. The unification mass scale is $3.3\times {10}^4\ge m_X\ge 6.4\times {10}^3$ GeV for $240\le m_R\le 6.4\times {10}^3$ GeV. Some consequences of the model are discussed.

• Received 26 January 1984

DOI:https://doi.org/10.1103/PhysRevD.30.1041