Plomp Vikram, Wang Xu-Dong, Kłos Jacek, Dagdigian Paul J, Lique François, Onvlee Jolijn, van de Meerakker Sebastiaan Y T
Radboud University, Institute for Molecules and Materials, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
University of Maryland, Department of Physics, Joint Quantum Institute, College Park, Maryland 20742, United States of America.
J Phys Chem Lett. 2024 May 2;15(17):4602-4611. doi: 10.1021/acs.jpclett.3c03379. Epub 2024 Apr 19.
An intriguing phenomenon in molecular collisions is the occurrence of scattering resonances, which originate from bound and quasi-bound states supported by the interaction potential at low collision energies. The resonance effects in the scattering behavior are extraordinarily sensitive to the interaction potential, and their observation provides one of the most stringent tests for theoretical models. We present high-resolution measurements of state-resolved angular scattering distributions for inelastic collisions between Zeeman-decelerated C() atoms and -H molecules at collision energies ranging from 77 cm down to 0.5 cm. Rapid variations in the angular distributions were observed, which can be attributed to the consecutive reduction of contributing partial waves and effects of scattering resonances. The measurements showed excellent agreement with distributions predicted by quantum scattering calculations. However, discrepancies were found at specific collision energies, which most likely originate from an incorrectly predicted quasi-bound state. These observations provide exciting prospects for further high-precision and low-energy investigations of scattering processes that involve paramagnetic species.
分子碰撞中一个有趣的现象是散射共振的出现，它源于低碰撞能量下相互作用势所支持的束缚态和准束缚态。散射行为中的共振效应对于相互作用势极其敏感，对其进行观测为理论模型提供了最严格的测试之一。我们展示了在77厘米至0.5厘米的碰撞能量范围内，对塞曼减速的C（）原子与 -H分子之间非弹性碰撞的态分辨角散射分布的高分辨率测量结果。观测到角分布的快速变化，这可归因于贡献分波的连续减少和散射共振的影响。测量结果与量子散射计算预测的分布显示出极好的一致性。然而，在特定碰撞能量下发现了差异，这很可能源于对准束缚态的错误预测。这些观测结果为进一步高精度、低能量研究涉及顺磁物种的散射过程提供了令人兴奋的前景。
