\right) \left( U\left( \mu r_{ji},\Lambda \right) -G\left( r_{ji},\Lambda
\right) \right) \right. \right.  \nonumber \\
&&+\left. {\bf S}_{ij}\left( {\mbox{\boldmath $\hat r$}}_{ji},{%
\mbox{\boldmath $\hat r$}}_{ji}\right) U\left( m_sr_{kj},\Lambda \right)
U_2\left( \mu r_{ji},\Lambda \right) \right]  \nonumber \\
&& +\lambda \frac{m_s}\mu 
\left[ {\bf S}_{ij}\left( {\mbox{\boldmath $\hat r$}}_{ji},{\mbox{\boldmath $\hat r$}}_{kj}\right)
+{\mbox{\boldmath $\hat r$}}_{ji}\cdot {\mbox{\boldmath $\hat r$}}_{kj} \;
{\mbox{\boldmath$\sigma $} }^{(i)}\cdot { \mbox{\boldmath$\sigma $ } }^{(j)} \right] 
\nonumber\\
&& \left. \times U_1\left(\mu r_{ji},\Lambda \right) U_1\left( m_sr_{kj},\Lambda \right) 
\right\} ,\end{aligned}$$

where $${\bf S}_{ij}\left( {\mbox{\boldmath $ \hat r$}}_{ji},{\mbox{\boldmath$ \hat r$}}_{kj}\right) 
=3{\mbox{\boldmath $\sigma $} }^{(i)}\cdot {\mbox{\boldmath
$\hat r$}}_{ji}{\mbox{\boldmath $\sigma $} }^{(j)}\cdot {\mbox{\boldmath
$\hat r$}}_{kj}-{\bf \hat r}_{ji}\cdot {\mbox{\boldmath $\hat r$}}_{kj}{%
\mbox{\boldmath $\sigma $} }^{(i)}\cdot \mbox{\boldmath $\sigma $}^{(j)}.$$

Discussion
==========

Initially, we discuss the role of chiral symmetry in the results of the previous section. Inspecting eq.(25), one notes that all the terms of the potential contain two gradients, reflecting the fact that they come from eq.(22), which is a uniform second order polynomial in meson momenta, as expected from a calculation based on chiral symmetry. This feature of the problem is independent of $\lambda$. On the other hand, the detailed form of the potential is quite sensitive to this parameter. The value $\lambda=0$ corresponds to a scalar field, denoted by $\sigma$, 