Comments on SO/Sp gauge theories from brane configurations with an O6 plane - art. no. 046001

We use the M theory approach in the presence of an orientifold O6 plane to understand some aspects of the moduli space of vacua for N=1 supersymmetric SO(N-c)/Sp(N-c) gauge theories in four dimensions. By exploiting some gene ral properties of the O6 orientifold, we reproduce some results obtained pr eviously with an orientifold O4 plane when the flavor group arises from the world volume dynamics of D6 branes. By using semi-infinite D4 branes inste ad of D6 branes, we derive the most general form of the rotated curve descr ibing the moduli space of vacua for N=1 supersymmetric gauge theory. [S0556 -2821(99)07402-0].