Strongly coupled 't Hooft model on the lattice - art. no. 054510

We study the strong coupling limit of the one-flavor and two-flavor massles s 't Hooft models, large-N-c-color QCD(2), on a lattice. We use staggered f ermions and the Hamiltonian approach to lattice gauge theories. We show tha t the one-flavor model is effectively described by the antiferromagnetic Is ing model, whose ground state is the vacuum of the gauge model in the infin ite coupling limit; expanding around this ground state we derive a strong c oupling expansion and compute the lowest lying hadron masses as well as the chiral condensate of the gauge theory. Our lattice computation well reprod uces the results of the continuum theory. Baryons are massless in the infin ite coupling limit; they acquire a mass already at the second order in the strong coupling expansion in agreement with the Witten argument that baryon s are the QCD solitons. The spectrum and chiral condensate of the two-flavo r model are effectively described in terms of observables of the quantum an tiferromagnetic Heisenberg model. We explicitly write the lowest lying hadr on masses and chiral condensate in terms of spin-spin correlators on the gr ound state of the spin model. We show that the planar limit (N-c --> infini ty) of the gauge model corresponds to the large spin limit (S --> infinity) of the antiferromagnet and compute the hadron mass spectrum in this limit finding that, also in this model, the pattern of chiral symmetry breaking o f the continuum theory is well reproduced on the lattice.