M Theory, Type IIA String and 4D N=1 SUSY SU(N_L) X SU(N_R) Gauge Theory

SU(N_L) X SU(N_R) gauge theories are investigated as effective field theories on D_4 branes in type IIA string theory. The classical gauge configuration is shown to match quantitatively with a corresponding classical U(N_L) X U(N_R) gauge theory. Quantum effects freeze the U(1) gauge factors and turn some parameters into moduli. The SU(N_L) X SU(N_R) quantum model is realized in M theory. Starting with an N=2 configuration (parallel NS fivebranes), the rotation of a single NS fivebrane is considered. Generically this leads to a complete lifting of the Coulomb moduli space. The implications of this result to field theory and the dynamics of branes are discussed. When the initial M fivebrane is reducible, part of the Coulomb branch may survive. Some such situations are considered, leading to curves describing the effective gauge couplings for N=1 models. The generalization to models with more gauge group factors is also discussed.