Fissionlike decay of 20Ne: Eccentric behavior in the B+B fusion processes.

Abstract

Cross sections for the fusion of $^{10}$,11B${+}^{10}$,11B have been measured in the energy range from 1.5 to 5 MeV/nucleon. The $^{10}\mathrm{B}$ system unexpectedly presents a hindered fusion cross section when compared to the $^{10}\mathrm{B}$ and $^{11}\mathrm{B}$ reactions and to standard model predictions. The missing fusion cross section was diverted to the $^{10}\mathrm{B}$ exit channel with a total kinetic energy characteristic of strongly damped collisions. Q values and kinematical analysis together with angular distributions suggest a binary symmetric decay of the composite $^{20}\mathrm{Ne}$ system.