Steuard Jensen (with Eduard Antonyan, Jeff Harvey, and David Kutasov). "NJL and QCD from String Theory." arXiv.org. hep-th/0604017 April 3, 2006.
(Not formally peer reviewed, but 86 citations in the literature.)
We study a configuration of D-branes in string theory that is described at low energies by a four-dimensional field theory with a dynamically broken chiral symmetry. In a certain region of the parameter space of the brane configuration the low-energy theory is a non-local generalization of the Nambu--Jona-Lasinio (NJL) model. This
vector model is in principle exactly solvable at large N_c and appears likely to dynamically break chiral symmetry at arbitrarily weak 't Hooft coupling. At strong coupling the dynamics is determined by the low-energy theory on D-branes living in the near-horizon geometry of other branes. In a different region of parameter space the brane construction gives rise to large N_c QCD. Thus the D-brane system interpolates between NJL and QCD.