SPONTANEOUS SYMMETRY-BREAKING IN DISCRETIZED LIGHT-CONE QUANTIZATION

Spontaneous symmetry breaking of the light-front Gross-Neveu model is studied in the framework of the discretized light-cone quantization. I ntroducing a scalar auxiliary field and adding its kinetic term, we ob tain a constraint on the longitudinal zero mode of the scalar field. T his zero-mode constraint is solved by using tile 1/N expansion. In the leading order, we find a nontrivial solution which gives the fermion nonzero mass and thus breaks the discrete symmetry of the model. It is essential for obtaining the nontrivial solution to treat adequately a n infrared divergence which appears in she continuum limit. We also-di scuss the constituent picture of the model. The Pock vacuum is trivial and an eigenstate of the light-cone Hamiltonian. In the large N limit , the Hamiltonian consists of the kinetic term of the fermion with dre ssed mass and the interaction term of these fermions.