Decay times of compound nuclei in heavy ion fusion reactions

The decay time of the compound nuclei has been studied using different statistical models. In the present work, we have improved the back-shifted microscopic level density model by including the pairing effect, an angular momentum-dependent moment of inertia, fission barriers, and a dynamical effect. The decay time of the compound nuclei is evaluated with and without dynamical effect and also compared with various statistical models and available experiments. It is also observed that the decay times of the compound nuclei formed during inverse kinematics is found to be larger when compared to direct kinematics at same excitation energy. Furthermore, the possible fission fragments have been identified using modified generalised liquid drop model. The identified fission fragments are compared with available experiments. The failure of the experiments to synthesize the superheavy element Z = 119 and 120 may be confirmed by the identification of fission fragments in these reactions. The predicted decay times of the compound nuclei and possible fission fragments gives a complete over view of failure of reactions to synthesize the superheavy element Z = 119 and 120. (author)