“…where pν = ( p, p 4 + iµ), the complex functions A, C and B can be defined by the quark equation with an effective gluon propagator. With a δ-function in momentum space for the effective gluon propagator (Munczek-Nemirovsky model [39]), it has been found that, in the D-S equation approach [20,24], the quark condensate increases with chemical potential, which is not consistent with the behavior given in composite operator approach of QCD [13], dilute instanton liquid model [21], Nanbu-Jona-Lasinio (NJL) model [23] and other approaches [14,16,22,25]. Looking over the characteristic of the Munczek-Nomirovsky model, which gives an infinity at zero exchanged momentum, we propose that the discrepancy of the variation behaviors of the chiral quark condensate against the chemical potential arises from the overestimated sudden enhancement in the far infrared region.…”