论文标题
$^{58,64} $ ni+$^{208} $ pb反应中多核转移过程的定量扩散方法
Quantal diffusion approach for multinucleon transfer processes in the $^{58,64}$Ni+$^{208}$Pb reactions: Toward the production of unknown neutron-rich nuclei
论文作者
论文摘要
背景：近年来，在研究库仑屏障周围的多核子转移反应方面已在实验和理论上都做出了重大努力，旨在生产未知中子富含中子的重型核。至关重要的是，基于微观理论提供可靠的理论预测，并具有足够的预测能力。 目的：本文旨在阐明基于随机平均场（SMF）理论的多核转移过程的量化扩散方法的适用性。对$^{64} $ ni+$^{208} $ pb的反应评估同位素生产横截面，$ e_ {c.m。} $ = 268 meV和$^{58} $ ni+$^{208} $ pb at $ e_ {c.mm。} $。 方法：三维时间依赖性的hartree-fock（TDHF）计算是针对具有Skyrme sly4d功能的一系列初始轨道角动量进行的。基于SMF理论得出的量化扩散方程，用于求解反应产物的中子和质子数量的方差和协方差，并从TDHF中占用的单颗粒轨道的时间演化获得了微观漂移和扩散系数。粒子蒸发和裂变均通过统计模型Gemini ++模拟了二次去激发过程。 结果：我们发现，定量扩散方法重现了丰富的反应产物的测得的横截面，包括弹丸样和类似靶的片段，以及转移诱导的裂变的片段。结果强调了超出均值效应在描述多核转移过程中的重要性。我们强调，一旦给出了能量密度功能，定量扩散描述就不会涉及任何可调参数。讨论了可能的未来方向。 （由于单词限制而缩短）
Background: In recent years, substantial efforts have been made for the study of multinucleon transfer reactions at energies around the Coulomb barrier both experimentally and theoretically, aiming at the production of unknown neutron-rich heavy nuclei. It is crucial to provide reliable theoretical predictions based on microscopic theories with sufficient predictive power. Purpose: This paper aims to clarify the applicability of the quantal diffusion approach based on the stochastic mean-field (SMF) theory for multinucleon transfer processes. Isotope production cross sections are evaluated for the reactions of $^{64}$Ni+$^{208}$Pb at $E_{c.m.}$=268 MeV and $^{58}$Ni+$^{208}$Pb at $E_{c.m.}$=270 MeV and are compared with available experimental data. Methods: Three-dimensional time-dependent Hartree-Fock (TDHF) calculations are carried out for a range of initial orbital angular momenta with Skyrme SLy4d functional. Quantal diffusion equations, derived based on the SMF theory, for variances and covariance of neutron and proton numbers of reaction products are solved, with microscopic drift and diffusion coefficients obtained from the time evolution of occupied single-particle orbitals in TDHF. Secondary deexcitation processes, both particle evaporation and fission, are simulated by a statistical model, GEMINI++. Results: We find that the quantal diffusion approach reproduces the measured cross sections for abundant reaction products, including both projectile-like and target-like fragments, as well as fragments of transfer-induced fission. The results underline the importance of beyond mean-field effects in describing multinucleon transfer processes. We emphasize that the quantal diffusion description does not involve any adjustable parameters, once an energy density functional is given. Possible future directions are discussed. (Shortened due to the word limit)
