  The Roth's two-pole approximation has been used by the present authors to
study the effects of the hybridization in the superconducting properties of a
strongly correlated electron system. The model used is the extended Hubbard
model which includes the $d-p$ hybridization, the $p$-band and a narrow
$d$-band. The present work is an extension a previous reference [Intern. Journ.
of Modern Phys. B, Vol. 18 No. 2 (2004) 241]. Nevertheless, some important
correlation functions necessary to estimate the Roth's band shift, are included
together with the temperature $T$ and the Coulomb interaction $U$ to describe
the superconductivity. The superconducting order parameter of a cuprate system,
is obtained following Beenen and Edwards formalism. Here, we investigate in
detail the change of the order parameter associated to temperature, Coulomb
interaction and Roth's band shift effects on superconductivity. The phase
diagram with $T_c$ versus the total occupation numbers $n_T$, shows the
difference respect to the previous work.
