Properties of nucleons and nuclear matter in the quark-diquark model and extension to finite density

We describe the nucleon as a quark-diquark bound state in a simple approximation to the full Faddeev method in the Nambu-Jona-Lasinio model. In the first part of this work, we concentrate on the role of axial vector diquark correlations for the static properties of the nucleon. In the second part, we construct an equation of state of nuclear matter based on the quark-diquark model for the single nucleon