The Semileptonic overline{B}longrightarrow Dloverline{ν} and overline{B_(s)}longrightarrow D_(s)loverline{ν} Decays in Isgur-Wise Approach

We consider a combination of linear confining and Hulth\'en potentials in the Hamiltonian and via the perturbation approach, report the corresponding Isgure-Wise function parameters. Next, we investigate the Isgur-Wise Function for $\overline{B}\longrightarrow Dl\overline{\nu}$ and $\overline{B_{s}}\longrightarrow D_{s}l\overline{\nu}$ semileptonic decays and report the decay width, branching ratio and $|V_{cb}|$ CKM matrix element. A comparison with other models and experimental values is included.