M-THEORY FIVEBRANE AND CONFINING PHASE OF N=1 SO(N-C) GAUGE-THEORIES

The moduli space of vacua for the confining phase of N = 1 SO(N-c) sup ersymmetric gauge theories in four dimensions is analyzed by studying the M theory fivebrane. The type IIA brane configuration consists of a single NS5 brane, multiple copies of NS'5 branes, D4 branes between t hem, and D6 branes intersecting D4 branes. We construct M theory fiveb rane configuration corresponding to the superpotential perturbation wh ere the power of adjoint field is connected to the number of NS'5 bran es. At a singular point in the moduli space where mutually local dyons become massless, the quadratic degeneracy of the N = 2 SO(N-c) hypere lliptic curve determines whether this singular point gives a N = 1 vac ua or not. The comparison of the meson vevs in M theory fivebrane conf iguration with field theory results turns out that the effective super potential by the ''integrating in'' method with enhanced gauge group S U(2) is exact. (C) 1998 Elsevier Science B.V. All rights reserved.