New perspective on cold fusion reactions: A microscopic description

TL;DR

This paper introduces a microscopic framework combining HFB and FBD models to better understand superheavy nuclei synthesis, accurately reproducing experimental data and revealing nuclear structure effects.

Contribution

It presents a self-consistent method that incorporates nuclear structure effects into fusion modeling, reducing phenomenological tuning at the fusion stage.

Findings

Reproduces experimental evaporation-residue cross sections for $^{48}$Ca + $^{208}$Pb.

Identifies a hyperasymmetric valley in PES driven by shell effects.

Shows a near-exponential decrease of $P_{CN}$ with compound-nucleus charge Z.

Abstract

A microscopic framework that combines the Hartree-Fock-Bogoliubov (HFB) approach with the fusion by diffusion (FBD) model is proposed to investigate the synthesis mechanism of superheavy nuclei (SHN). For the reaction $^{48}\text{Ca}+^{208}\text{Pb}$, the calculated evaporation-residue cross section (ERCS) reproduces the experimental data reasonably well. The method enables self-consistent extraction of the fusion injection point and inner barrier from HFB potential-energy surfaces (PES), thereby incorporating nuclear structure effects while eliminating phenomenological tuning at the fusion stage. For cold-fusion reactions, the PES features a hyperasymmetric valley driven by shell effects. This $^{208}$Pb anchored valley connects the entrance channel to compound nucleus formation and provides an exit channel for cluster decay. We further investigate the cold-fusion reactions $^{54}\text{Cr}+^{208}\text{Pb}$ and $^{58}\text{Fe}+^{208}\text{Pb}$, obtaining a near-exponential decrease of $P_{\text{CN}}$ with compound-nucleus charge $Z$, consistent with established systematics. This approach demonstrates a self-consistent framework that can reduce uncertainties in the fusion stage of SHN production.