Improved fixed center approximation of the Faddeev equations for the system with S=0

We extend the Fixed Center Approximation (FCA) to the Faddeev equations for the system with S=0, including the charge exchange mechanisms in the rescattering which have been ignored in former works within the FCA. We obtain similar results to those found before, but the binding is reduced by 6 MeV. At the same time we also evaluate the explicit contribution the πNΣ intermediate state in the three body system and find that it produces and additional small decrease in the binding of about 3 MeV. The system appears bound by about 35 MeV and the width omitting two body absorption, is about 50 MeV.