Spontaneous Supersymmetry Breaking, Negative Metric and Vacuum Energy

The supersymmetric Nambu-Jona-Lasinio model proposed by Cheng, Dai, Faisel and Kong is re-analyzed by using an auxiliary superfield method in which a hidden local U(1) symmetry emerges. It is shown that, in the healthy field-space region where no negative metric particles appear, only SUSY preserving vacua can be realized in the weak coupling regime and a composite massive spin-1 supermultiplets appear as a result of spontaneous breaking of the hidden local U(1) symmetry. In the strong coupling regime, on the other hand, SUSY is dynamically broken, but it is always accompanied by negative metric particles.