Synthesis mechanism of superheavy element 120: a dinuclear system model approach with microscopic inputs

TL;DR

This paper uses a microscopic approach combining the dinuclear system model with finite-temperature covariant density functional theory to predict synthesis cross sections for superheavy element 120.

Contribution

It introduces a method to generate input physical quantities microscopically for the dinuclear system model, improving predictions of superheavy element synthesis.

Findings

Successfully reproduces experimental results for cold and hot fusion reactions.

Predicts maximum synthesis cross sections for four reactions leading to element 120.

Identifies optimal reaction conditions for synthesizing element 120.

Abstract

The dinuclear system model incorporates several essential input physical quantities, including nuclear mass, fission barrier, shell correction energy, level density parameter, and shell damping factor, etc., which are derived from diverse nuclear structure models. To achieve theoretical consistency, we try to generate these essential input physical quantities from the finite-temperature covariant density functional theory using PC-PK1 energy density functional, with pairing correlations treated via the BCS approach. With microscopically determined input parameters, the dinuclear system model can successfully reproduce experimental results for: (i) cold fusion reaction systems ($^{48}$Ca + $^{204,206-208}$Pb $\rightarrow$ $^{252,254-256}$No$^*$), and (ii) hot fusion reaction systems ($^{48}$Ca + $^{239,240,242,244}$Pu $\rightarrow$ $^{287,288,290,292}$Fl$^*$). Furthermore, we perform calculations for the fusion reactions $^{50}$Ti+$^{249}$Cf, $^{51}$V+$^{249}$Bk, $^{54}$Cr+$^{248}$Cm, and $^{55}$Mn+$^{243}$Am, targeting the synthesis of element 120. It is found that the maximum synthesis cross section for these four reactions are 48.20 fb, 12.33 fb, 5.25 fb, 0.47 fb corresponding to $^{50}$Ti($^{249}$Cf,4n)$^{295}$120 at $E^*_{\rm CN}$ = 41 MeV, $^{51}$V($^{249}$Bk,3n)$^{297}$120 at $E^*_{\rm CN}$ = 34 MeV, $^{54}$Cr($^{248}$Cm,3n)$^{299}$120 at $E^*_{\rm CN}$ = 32 MeV, $^{55}$Mn($^{243}$Am,5n)$^{293}$120 at $E^*_{\rm CN}$ = 53 MeV, respectively.