论文标题

核物理中时间依赖的发电机坐标方法

The time-dependent generator coordinate method in nuclear physics

论文作者

Verriere, Marc, Regnier, David

论文摘要

集体行为的出现和大幅度运动的存在都是核结构和反应领域的核心特征。从理论的角度来看,描述这种现象需要增加系统多体波的复杂性,以说明远程相关性。朝着这个方向发展时,挑战之一是将方法保持在我们当前的计算资源中,同时获得研究现象的最大预测能力。在发电机坐标方法(GCM)中,多体波函数是(通常是非正交的)多体状态(发电机状态)的线性叠加,该状态由一些集体坐标标记。这种方法已被广泛用于结构研究中,以恢复单一参考方法破裂的对称性。在反应领域,已经开发并应用了其时间依赖性版本(TDGCM),以预测集体波动起着至关重要的作用的重型离子碰撞或裂变的动力学。在这篇综述中,我们介绍了TDGCM在核反应中的最新发展和应用。我们回想起TDGCM的形式推导及其最常见的近似处理,即高斯重叠近似。我们还强调了Schrödinger集体内部模型(SCIM)变体,重点是将准粒子激发纳入描述。最后,我们重点介绍了与时间依赖性发电机状态建立的TDGCM相关的一些探索性研究。

The emergence of collective behaviors and the existence of large amplitude motions are both central features in the fields of nuclear structure and reactions. From a theoretical point of view, describing such phenomena requires increasing the complexity of the many-body wavefunction of the system to account for long-range correlations. One of the challenges, when going in this direction, is to keep the approach tractable within our current computational resources while gaining a maximum of predictive power for the phenomenon under study. In the Generator Coordinate Method (GCM), the many-body wave function is a linear superposition of (generally non-orthogonal) many-body states (the generator states) labeled by a few collective coordinates. Such a method has been widely used in structure studies to restore the symmetries broken by single-reference approaches. In the domain of reactions, its time-dependent version (TDGCM) has been developed and applied to predict the dynamics of heavy-ion collisions or fission where the collective fluctuations play an essential role. In this review, we present the recent developments and applications of the TDGCM in nuclear reactions. We recall the formal derivations of the TDGCM and its most common approximate treatment, the Gaussian Overlap Approximation. We also emphasize the Schrödinger Collective-Intrinsic Model (SCIM) variant focused on the inclusion of quasiparticle excitations into the description. Finally, we highlight several exploratory studies related to a TDGCM built on time-dependent generator states.

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