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arXiv 2009.01159nucl-th
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连续介质在单中子晕核直接反应中的作用:一维模型

Role of continuum in nuclear direct reactions with one-neutron halo nuclei: a one-dimensional model

Laura Moschini, Antonio M. Moro, Andrea Vitturi

摘要:

本文研究了一维势阱与另一势阱碰撞过程中单粒子波函数的演化,它可以看作是一个中子晕核与另一核散射问题的一个简单模型。这构成了一个有效的三体问题,其三维解可能非常复杂,特别是当要考虑分裂和重排通道时。我们的一维模型提供了这个问题的基本三体性质,并允许一个更简单的应用程序和评估不同的解决方案的方法。为了进一步简化问题,我们假设代表抛射体的势阱按照预定的经典轨迹运动,尽管“价”粒子的内部运动被完全量子力学地处理。这对应于散射问题的半经典方法。不同的方法进行了研究,以了解涉及单体晕状系统的动力学:“精确”的薛定谔方程的时间依赖性的解决方案相比,一个数值连续离散耦合通道(CC)计算,提出了各种模型的情况下,包括不同的反应通道。这个框架使我们能够讨论的反应机制和连续的作用,其列入CC计算结果是至关重要的再现“精确”的解决方案,即使当初始和最终状态是很好的约束。我们还将每个动态情况与在三维(3D)CC框架中解决的类似问题联系起来,讨论了通常3D模型中遇到的主要挑战。

英文摘要:

We study the evolution of a single-particle wave function during the collision of a one dimensional potential well by another well, which can be regarded as a simple model for the problem of the scattering of a one-neutron halo nucleus by another nucleus. This constitutes an effective three-body problem, whose solution in three dimensions can be extremely complicated, particularly when breakup and rearrangement channels are to be considered. Our one-dimensional model provides the essential three-body nature of this problem, and allows for a much simpler application and assessment of different methods of solution. To simplify further the problem, we assume that the potential well representing the projectile moves according to a predetermined classical trajectory, although the internal motion of the "valence" particle is treated fully quantum-mechanically. This corresponds to a semiclassical approach of the scattering problem. Different approaches are investigated to understand the dynamics involving one-body halo-like systems: the "exact" time-dependent solution of the Schrödinger equation is compared to a numerical continuum-discretized coupled-channels (CC) calculation presenting various model cases including different reaction channels. This framework allows us to discuss the reaction mechanism and the role of continuum, whose inclusion in the CC calculation results to be crucial to reproduce the "exact" solution, even when the initial and final states are well bound. We also link each dynamical situation with analogous problem solved in a three dimensional (3D) CC framework, discussing the main challenges experienced in the usual 3D models.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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