of the nucleon angular momentum.

Another important conclusion was issued from the definition of the stability concept of a dynamical system. For the aforementioned cases the dispersed trajectory pack periodically regroups on the frontier that delimits the forbidden zone of the phase space. This type of behaviour corresponds with the definition of stability given by Poisson (for e.g., in [@holmes-96]). We will herewith remind that the Poisson stability defines as steady the movement of a particle system of which configuration comes close, from time to time, to the initial position.

At a first glance, on the simple [UCE]{} case one can distinguish two extremities of the radius of the particle periodic motion in the 2D potential well: $r_{min}(UCE) \approx 1.42\ \rm{fm}$, and $r_{Max}(UCE) \approx 5.96\ \rm{fm}$. These values correspond to the roots of the boundary equation:

$$E = \frac{p_{\theta}^2}{2mr^2}+V\left(r \right),$$

for a given one-nucleon energy $E$, when the radial component of velocity vanishes ($\stackrel{\cdot }{r}=0$).

The analysis of the particle motion in the configuration space is similar to that applied to any system with bound unclosed trajectories. The nucleonic motion takes place within a circular crown (the so-called *annulus*) determined by the concentric circles of $r_{min}$ and $r_{Max}$ radii. The 