Incomplete Fusion inC12+Gd160Collisions Interpreted in Terms of a Generalized Concept of Critical Angular Momentum

The energy dependence of incomplete-fusion reactions ${}_{}{}^{160}{}_{}{}^{}\mathrm{Gd}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,$\alpha$) and ${}_{}{}^{160}{}_{}{}^{}\mathrm{Gd}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,$2\alpha$) has been studied by means of $\alpha -\gamma$ coincidences in the range of bombarding energies 7.5-16.7 MeV/A. Excitation functions are interpreted in terms of a generalized concept of critical angular momentum. An energy threshold (of about 15 MeV/A) is predicted at which projectile fragmentation processes set in rapidly at the cost of the decreasing cross section for binary massive-transfer reactions.