Multidimensional Dirac strings and the Witten index of SYMCS theories with groups of higher rank

Abstract

We discuss generalized Dirac strings associated with a given Lie group. They live in r-dimensional complex space (r being the rank of the group). Such strings show up in the effective Born-Oppenheimer Hamiltonian for 3d supersymmetric Yang-Mills-Chern-Simons theories, brought up by the gluon loops. We calculate accurately the number of the vacuum states in the effective Hamiltonian associated with these strings. We also show that these states are irrelevant for the final SYMCS vacuum counting. The Witten index of SYMCS theories depends thus only on the strings generated by fermion loops and carrying fractional generalized fluxes.