BOUND-STATE-SPECTRUM OF SU(N) MASSIVE GROSS-NEVEU MODEL

Applying the infinite momentum frame technique, we solve the charge zero sector of the SU(N) massive Gross-Neveu model. For positive charge conjugation state (C=1), the boson spectrum at large N limit is equivalent to the result obtained from light cone approach with mean field approximations. The bound state energy behaves similar to that of semiclassical calculation and the leading term appears at 1/N-2 order. Also, there is a negative charge conjugation state (C=-1). This spectrum is found to be identical to that of the U(1) massive Thirring model for any value of N. Further, we fmd a phase transition at some critical coupling for N=0 case, which may correspond to that of the random bond Ising model.