  We present a lattice study of a four fermion theory, known as Nambu
Jona-Lasinio (NJL) theory, via Wilson fermions. Four fermion interactions
naturally occur in several extensions of the Standard Model as a low energy
parameterisation of a more fundamental theory. In models of dynamical
electroweak symmetry breaking these operators, at an effective level, are used
to endow the Standard Model fermions with masses. Furthermore these operators,
when sufficiently strong, can drastically modify the fundamental composite
dynamics by, for example, turning a strongly coupled infrared conformal theory
into a (near) conformal one with desirable features for model building. As
first step, we study spontaneous chiral symmetry breaking for the lattice
version of the NJL model.
