The energy spectra of the $\alpha$ particles emitted in the reactions ${}^{16}$O (7–10 MeV/nucleon)+${}^{12}$C have been measured in the center-of-mass angular range of ${25}^{\circ }\lesssim {\theta }_{\text{c.m.}}\lesssim {70}^{\circ }$. The experimental energy spectra have been compared with those obtained from the statistical model calculation with “deformability” parameters predicted by rotating liquid drop model (rldm) and also fitted the same with optimized deformability parameters, which are quite different from the respective rldm values. The data have also been found to be explained quite well using “frozen” deformation approximation, where the deformability parameters have been kept fixed at rldm values of the parent nucleus throughout the decay process. The effective radius in the latter case is smaller compared to that obtained using the optimized parameters; however, in both cases, the deformations (effective radii) are larger than the corresponding rldm values. So, considering the uncertainties in the estimation of actual compound nucleus deformations, it can, only qualitatively, be said that equilibrium orbiting, which is similar to particle evaporation in time scale, could also be one of the contributing factors for the observed deformation.

• Received 5 March 2012

DOI:https://doi.org/10.1103/PhysRevC.87.024602