  In the Bourrely-Soffer-Wu model (BSW) we introduce for the pomeron a new
opaqueness in impact parameter space in terms of different quark contributions
described by a Fermi-Dirac distribution. In order to check the validity of this
assumption we consider $p~p$, $\bar p~p$, and $\pi^{\pm}~p$ elastic scattering.
We emphasize the role of the gluon above the diffraction peak in the
differential cross sections. Once these contributions are determined we extend
the model to light nuclei elastic reactions like $p~d$, $p~^4\mbox{He}$ and
$\pi^{\pm}~^4\mbox{He}$. The results obtained show a good description of all
these elastic processes over the available experimental energy range and
moderate momentum transfer.
