Effects of the entrance channel and fission barrier in synthesis of superheavy element $Z$=120

TL;DR

This study compares fusion and evaporation residue cross sections for two reactions aimed at synthesizing superheavy element Z=120, highlighting the influence of entrance channel properties and nuclear mass models on production probabilities.

Contribution

It provides a comparative analysis of two reaction pathways for superheavy element synthesis using combined models and different nuclear mass calculations, identifying the more favorable reaction.

Findings

$^{50}$Ti+$^{249}$Cf has higher fusion excitation function than $^{54}$Cr+$^{248}$Cm.

Evaporation residue cross sections are larger for the more asymmetric $^{50}$Ti+$^{249}$Cf reaction.

Using different nuclear mass models significantly affects the predicted cross sections.

Abstract

The fusion and evaporation residue cross sections for the $^{50}$Ti+$^{249}$Cf and $^{54}$Cr+$^{248}$Cm reactions calculated by the combined dinuclear system and advanced statistical models are compared. These reactions are considered to be used to synthesize the heaviest superheavy element. The $^{50}$Ti+$^{249}$Cf reaction is more mass asymmetric than $^{54}$Cr+$^{248}$Cm and the fusion excitation function for the former reaction is higher than the one for the latter reaction. The evaporation residue excitation functions for the mass asymmetric reaction is higher in comparison with the one of the $^{54}$Cr+$^{248}$Cm reaction. The use of the mass values of superheavy nuclei calculated in the framework of the macroscopic-microscopic model by the Warsaw group leads to smaller evaporation residue cross section for both the reactions in comparison with the case of using the masses calculated by Peter M\"oller {\it et al}. The $^{50}$Ti+$^{249}$Cf reaction is more favorable in comparison with the $^{54}$Cr+$^{248}$Cm reaction: the maximum values of the excitation function of the 3n-channel of the evaporation residue formation for the $^{50}$Ti+$^{249}$Cf and $^{54}$Cr+$^{248}$Cm reactions are about 0.1 and 0.07 pb, respectively, but the yield of the 4n-channel for the former reaction is lower (0.004 pb) in comparison with the one (0.01 pb) for the latter reaction.