Dissipative collisions in 16 O + 27 Al at E lab =116 MeV

The inclusive energy distributions of fragments $(3l~Zl~7)$ emitted in the reaction ${}^{16}\mathrm{O}{+}^{27}\mathrm{Al}$ at ${E}_{\mathrm{lab}}=116\mathrm{MeV}$ have been measured in the angular range ${\ensuremath{\theta}}_{\mathrm{lab}}=15\ifmmode^\circ\else\textdegree\fi{}\char21{}115\ifmmode^\circ\else\textdegree\fi{}.$ A nonlinear optimization procedure using multiple Gaussian distribution functions has been proposed to extract the fusion-fission and deep-inelastic components of the fragment emission from the experimental data. The angular distributions of the fragments, thus obtained, from the deep-inelastic component are found to fall off faster than those from the fusion-fission component, indicating shorter lifetimes of the emitting dinuclear systems. The lifetimes of the intermediate dinuclear configurations have been estimated using a diffractive Regge-pole model. The lifetimes thus extracted $[\ensuremath{\sim}(1\char21{}5)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}22}\mathrm{sec}]$ are found to decrease with the increase in the fragment charge. Optimum Q values are also found to increase with increasing charge transfer, i.e., with the decrease in fragment charge.