RUI: Path Integral Approach to Ion-Impact Collisions

原子碰撞的研究提供了关于自然界基本力之一的重要信息。原子碰撞的研究成果广泛应用于等离子体物理、天体物理、生物物理等领域。除了提供对重离子碰撞的更好的全面理解之外，这是这项工作的主要重点，这项工作将把其他物理领域的一种众所周知的技术带入原子和分子碰撞研究，并可能导致原子碰撞社区和其他相关领域之间的额外重叠和合作。该项目的另一个重要方面是将本科生纳入前沿研究。通过参与这个项目，学生将通过代码开发和数据分析获得宝贵的实践研究经验。他们还将在区域和国家会议上展示他们的成果，希望这将使他们对科学研究有一个更全球性的看法。少体问题是物理学中最基本的、未解决的问题之一。当两个以上的粒子通过库仑力相互作用时，系统的动力学就不能精确描述了。因此，理论必须诉诸近似，理论和实验之间的任何差异都必须是近似的结果。目前的理论模型与最近的实验结果的比较显示，目前的模型的一些显着的局限性。特别是，碰撞的动力学，其中一些碰撞碎片被发现在一个完整的三维几何形状是不理解的。已知这些三维碰撞背后的基本机制是量子力学效应的结果，但目前的理论无法准确描述碰撞动力学。本计画的目的是发展一个新的量子力学理论模型，以应用路径积分技术来研究离子与原子碰撞。路径积分方法是一种在物理学其他领域广泛使用的方法，但尚未应用于重离子碰撞的研究。这种特殊的技术将允许包含重要的量子力学相互作用，并提供对碰撞过程中粒子轨迹的直观理解。该项目的技术细节包括使用路径积分法开发一个计算模型，用于重离子射弹的电离和俘获过程。该方法将利用经典路径周围的拉格朗日展开，其中与经典路径的偏离表示粒子的量子涨落。对于电子俘获碰撞，将研究射弹-核相互作用和靶电子相关的作用。电子捕获碰撞与高弹丸能量和大散射角也将进行研究，目的是更好地理解托马斯机制，并确定是否可能的衍射效应存在于这些碰撞。对于电离过程，将研究在散射平面之外发现喷射电子的碰撞，重点是射弹-核相互作用以及射弹和靶核之间紧密碰撞的作用。

The study of atomic collisions provides important information about one of the fundamental forces of nature. The results of atomic collisions research are widely used in fields such as plasma physics, astrophysics, biophysics, and many other areas. In addition to providing a better overall understanding of heavy-ion collisions, which is the principal focus of the effort, this work will bring a well-known technique from other areas of physics into atomic and molecular collisions research, and possibly lead to additional overlap and collaborations between the atomic collisions community and other related fields. Another important aspect of this project is the inclusion of undergraduate students in cutting-edge research. By participating in this project, students will gain valuable hands-on research experience through code development and data analysis. They will also present their results at regional and national conferences, which will hopefully give them a more global view of scientific research.The few-body problem is one of the most fundamental, unsolved problems in physics. When more than two particles interact through the Coulomb force, the dynamics of the system cannot be described exactly. As a result, theory must resort to approximations, and any discrepancies that result between theory and experiment must be a result of the approximations. A comparison of current theoretical models with recent experimental results reveals some striking limitations of the current models. In particular, the dynamics of collisions in which some of the collision fragments are found in a full 3-dimensional geometry is not understood. The underlying mechanism behind these 3-dimensional collisions is known to be a result of quantum mechanical effects, but current theories cannot accurately describe the collision dynamics. The objective of this project is to develop a novel quantum mechanical theoretical model for the study of ion-impact atomic collisions through the use of the path integral technique. The path integral method is a well-known technique used in other areas of physics, but has not been applied to the study of heavy-ion collisions. This particular technique will allow for the inclusion of important quantum mechanical interactions, as well as provide an intuitive understanding of particle trajectories during the collision. The technical details of the project include the development of a computational model using the path integral method for ionization and capture processes with heavy-ion projectiles. The method will utilize an expansion of the Lagrangian around the classical path, where the deviation from the classical path represents the quantum fluctuations of the particle. For electron capture collisions, the role of the projectile-nuclear interaction and target electron correlation will be studied. Electron capture collisions with high projectile energy and large scattering angle will also be studied with the objective of better understanding the Thomas mechanism, and determining if possible diffraction effects exist in these collisions. For ionization processes, collisions in which the ejected electron is found outside of the scattering plane will be studied, with a focus on projectile-nuclear interactions and the role of close collisions between the projectile and the target nucleus.