Absence of entrance-channel effects in the high-energy gamma -ray emission from 146Gd.

Abstract

The $\ensuremath{\gamma}$ decay of the giant dipole resonance has been studied with mass-symmetric and mass-asymmetric fusion-evaporation reactions similar to those for which entrance-channel effects were previously reported in the population of superdeformed bands. No entrance-channel effects have been observed in the high-energy $\ensuremath{\gamma}$-ray spectra associated with the decay of the $^{146}\mathrm{Gd}$ compound nucleus populated at an excitation energy of 82 MeV via the reactions $^{30}\mathrm{Si}$+$^{116}\mathrm{Sn}$ and $^{76}\mathrm{Ge}$+$^{70}\mathrm{Ge}$. The absence of entrance-channel effects in the present data set is well explained by dissipative collision calculations.