  In a recent paper we have analyzed the Spinor Theory of Gravity (STG) which
is based on the intimate relation between Fermi (weak) interaction and gravity.
We presented the hypothesis that the effect of matter upon the metric that
represents gravitational interaction in General Relativity is an effective one.
This lead us to consider gravitation to be the result of the interaction of two
neutral spinorial fields (G-neutrinos) $\Psi_g$ and $\Omega_g$ with all kinds
of matter and energy through the generation of such effective metric. In other
words, the universal metric that represents gravitational interaction in the
framework of General Relativity is constructed with the weak currents
associated to $\Psi_g$ and $\Omega_g$. In the first paper we have shown that
when only one spinor exists, the effective metric of a static and spherically
symmetric configuration is identical to the Schwarzschild geometry of GR. In
the present paper we go one step further and consider the case in which the
field $\Psi_g$ has a self-interaction. The solution of a static and spherically
symmetric configuration is distinct from the previous one. This new solution
presents another horizon that we compare with the case of Schwarzschild.
