  The mass of the nucleon is studied in a chiral quark-diquark model. Both
scalar and axial-vector diquarks are taken into account for the construction of
the nucleon state. After the hadronization procedure to obtain an effective
meson-baryon Lagrangian, the quark-diquark self-energy is calculated in order
to generate the baryon kinetic term as well as the mass of the nucleon. It
turns out that both the scalar and axial-vector parts of the self-energy are
attractive for the mass of the nucleon. We investigate the range of parameters
that can reproduce the mass of the nucleon.
