Relative emergence of fission and quasi-fission in Z=116 superheavy nucleus

Abstract

The fusion and subsequent decay analysis of Z=116 superheavy nucleus formed via ⁴⁸Ca+²⁴⁸Cm→²⁹⁶Lv^*, ⁵⁰Ti+²⁴⁴Pu→²⁹⁴Lv^*,and ⁵⁸Fe+²³²Th→²⁹⁰Lv^* reactions is carried out using extended ℓ-summed Wong model and dynamical cluster decay model (DCM), respectively. First of all, the experimentally available fusion-fission (A/2±20) data is adequately addressed for ²⁹⁶Lv^* and ²⁹⁴Lv^* superheavy nuclei using extended ℓ-summed Wong model and the predictions are made for fusion-fission excitation function of ²⁹⁰Lv^* nucleus. It is observed that with decrease in mass-asymmetry (η), the contribution of fusion-fission component decreases. This drop is steeper for ⁵⁰Ti to ⁵⁸Fe as compared to that for ⁴⁸Ca to ⁵⁰Ti. The calculated values of compound nucleus formation probability (P_CN) are highest for ⁴⁸Ca followed by ⁵⁰Ti and ⁵⁸Fe. Finally, the mass distribution of decay fragments is studied for ²⁹⁶Lv^*, ²⁹⁴Lv^*, and ²⁹⁰Lv^* nuclei using DCM at near barrier energies. A valley in A_CN/2 region results in asymmetric mass distribution for ²⁹⁶Lv^* which becomes relatively symmetric for the lighter isotope ²⁹⁰Lv^*.