Dynamical Symmetry Breaking of Extended Gauge Symmetries

We construct asymptotically free gauge theories exhibiting dynamical breaking of the left-right, strong-electroweak gauge group $G_{LR} = {\rm SU}(3)_c \times {\rm SU}(2)_L \times {\rm SU}(2)_R \times {\rm U}(1)_{B-L}$, and its extension to the Pati-Salam gauge group $G_{422}={\rm SU}(4)_{PS} \times {\rm SU}(2)_L \times {\rm SU}(2)_R$. The models incorporate technicolor for electroweak breaking, and extended technicolor for the breaking of $G_{LR}$ and $G_{422}$ and the generation of fermion masses, including a seesaw mechanism for neutrino masses. These models explain why $G_{LR}$ and $G_{422}$ break to ${\rm SU}(3)_c \times {\rm SU}(2)_L \times {\rm U}(1)_Y$, and why this takes place at a scale ($\sim 10^3$ TeV) which is large compared to the electroweak scale.