Partial-unification mass scales for the group ${\left[\mathrm{S}{\mathrm{U}}_c \mathrm{}\right(4\left)\right]}^2\times \mathrm{S}{\mathrm{U}}_L\mathrm{}\left(2\right)\mathrm{}\times \mathrm{S}{\mathrm{U}}_R\mathrm{}\left(2\right)\mathrm{}$ are studied. We show that for this group the intermediate mass scale $m_R$ is given by $300\le m_R\le {10}^7$ GeV for the partial-unification mass scale $M_X$ in the range $5\times {10}^{12}\ge M_X\ge 3\times {10}^{10}$ GeV. This is in contrast to other models for which $m_R\ge {10}^9$ GeV.

• Received 27 September 1982

DOI:https://doi.org/10.1103/PhysRevD.27.2747