  Superconformal indices of 4d \N=1 SYM theories with SU(N) and SP(2N) gauge
groups are investigated for N_f=N and N_f=N+1 flavors, respectively. These
indices vanish for generic values of the flavor fugacities. However, for a
singular submanifold of fugacities they behave like the Dirac delta functions
and describe the chiral symmetry breaking phenomenon. Similar picture holds for
partition functions of 3d supersymmetric field theories with the chiral
symmetry breaking.
