Derivation of capture cross section from quasielastic excitation function

The relationship between the quasielastic excitation function and the capture cross section is derived. The quasielastic data is shown to be a useful tool to extract the capture cross sections and the angular momenta of the captured systems for the reactions $^{16}$O+$^{144,154}$Sm,$^{208}$Pb, $^{20}$Ne+$^{208}$Pb, and $^{32}$S+$^{90,96}$Zr at near and above the Coulomb barrier energies.