Witten index, defined as ${\rm Tr}(-1)^F$, determines if supersymmetry is spontaneously broken or not for a given model. However, it is also known that supersymmetry can be dynamically broken. One could think of a mechanism (yet to be implemented if any) à la Nambu-Jona-Lasinio model for chiral symmetry in QCD. In this case, how does Witten index change? I think it should reflect the fact that, even if we are not requiring explicitly a selected ground state breaking symmetry, particle masses are lifted and a gap equation is satisfied.

A more general question is: if Witten index applies as well to dynamical breaking of supersymmetry, for all the models one can possibly conceive.

As usual, good references are welcome.

Thanks.

This post imported from StackExchange Physics at 2014-12-22 11:37 (UTC), posted by SE-user Jon