On SUSY breaking and /χSB from string duals

We find regular string duals of three-dimensional N=1 SYM with a Chern-Simons interaction at level k for SO and Sp gauge groups. Using the string dual we exactly reproduce the conjectured pattern of supersymmetry breaking proposed by Witten by showing that there is dynamical supersymmetry breaking for k< h/2 while supersymmetry remains unbroken for k⩾ h/2, where h is the dual Coxeter number of the gauge group. We also find regular string duals of four-dimensional N=1 SYM for SO and Sp gauge groups and exactly reproduce the expected pattern of chiral symmetry breaking Z_{2 h}→ Z₂ by analyzing the symmetries of the string solution.