STUDY OF THE NAMBU-JONA-LASINIO MODEL ON THE LATTICE

We present our full analysis of the two flavor Nambu-Jona-Lasinio model with SU(2)xSU(2) chiral symmetry on the four-dimensional hypercubic lattice with naive and Wilson fermions. We find that this model is an excellent toy field theory to investigate issues related to lattice QCD. We use the large-N approximation to leading order in 1/N to obtain nonperturbative analytical results over almost the whole parameter range. By using numerical simulations we estimate that the size of the 1/N corrections for most of the quantities we consider are smalt and in this way we strengthen the validity of the leading-order large-N calculations. We obtain results regarding the approach to the continuum chiral limit, the effects of the zero momentum fermionic modes on finite lattices, and the scalar and pseudoscalar spectrum.