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Full-Text Articles in Physics

Model For Scattering With Proliferating Resonances: Many Coupled Square Wells, Nirav P. Mehta, Kaden R. A Hazzard, Christopher Ticknor Dec 2018

Model For Scattering With Proliferating Resonances: Many Coupled Square Wells, Nirav P. Mehta, Kaden R. A Hazzard, Christopher Ticknor

Physics and Astronomy Faculty Research

We present a multichannel model for elastic interactions, composed of an arbitrary number of coupled finite square-well potentials, and derive semianalytic solutions for its scattering behavior. Despite the model's simplicity, it is flexible enough to include many coupled short-ranged resonances in the vicinity of the collision threshold, as is necessary to describe ongoing experiments in ultracold molecules and lanthanide atoms. We also introduce a simple but physically realistic statistical ensemble for parameters in this model. We compute the resulting probability distributions of nearest-neighbor resonance spacings and analyze them by fitting to the Brody distribution. We quantify the ability of alternative …


Real-Time Observation Of Molecular Spinning With Angular High-Harmonic Spectroscopy, Lixin He, Pengfei Lan, Anh-Thu Le, Baoning Wang, Bincheng Wang, Xiaosong Zhu, Peixiang Lu, C. D. Lin Oct 2018

Real-Time Observation Of Molecular Spinning With Angular High-Harmonic Spectroscopy, Lixin He, Pengfei Lan, Anh-Thu Le, Baoning Wang, Bincheng Wang, Xiaosong Zhu, Peixiang Lu, C. D. Lin

Physics Faculty Research & Creative Works

We demonstrate an angular high-harmonic spectroscopy method to probe the spinning dynamics of a molecular rotation wave packet in real time. With the excitation of two time-delayed, polarization-skewed pump pulses, the molecular ensemble is impulsively kicked to rotate unidirectionally, which is subsequently irradiated by another delayed probe pulse for high-order harmonic generation (HHG). The spatiotemporal evolution of the molecular rotation wave packet is visualized from the time-dependent angular distributions of the HHG yields and frequency shift measured at various polarization directions and time delays of the probe pulse. The observed frequency shift in HHG is demonstrated to arise from the …


Probing High-Momentum Protons And Neutrons In Neutron-Rich Nuclei, M. Duer, C. L. A. S. Collaboration, O. Hen, E. Piasetzky, H. Hakobyan, L. B. Weistein, M. Braverman, Gerard P. Gilfoyle, Et. Al. Aug 2018

Probing High-Momentum Protons And Neutrons In Neutron-Rich Nuclei, M. Duer, C. L. A. S. Collaboration, O. Hen, E. Piasetzky, H. Hakobyan, L. B. Weistein, M. Braverman, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

The atomic nucleus is one of the densest and most complex quantum-mechanical systems in nature. Nuclei account for nearly all the mass of the visible Universe. The properties of individual nucleons (protons and neutrons) in nuclei can be probed by scattering a high-energy particle from the nucleus and detecting this particle after it scatters, often also detecting an additional knocked-out proton. Analysis of electron- and proton-scattering experiments suggests that some nucleons in nuclei form close-proximity neutron–proton pairs with high nucleon momentum, greater than the nuclear Fermi momentum. However, how excess neutrons in neutron-rich nuclei form such close-proximity pairs remains unclear. …


Dynamic Effects In Electron Momentum Spectroscopy Of Sulfur Hexafluoride, Xing Wang, Shenyue Xu, Chuangang Ning, O. Al-Hagan, Pengfei Hu, Yongtao Zhao, Zhongfen Xu, Jingkang Deng, Enliang Wang, Xueguang Ren, Alexander Dorn, Don H. Madison Jun 2018

Dynamic Effects In Electron Momentum Spectroscopy Of Sulfur Hexafluoride, Xing Wang, Shenyue Xu, Chuangang Ning, O. Al-Hagan, Pengfei Hu, Yongtao Zhao, Zhongfen Xu, Jingkang Deng, Enliang Wang, Xueguang Ren, Alexander Dorn, Don H. Madison

Physics Faculty Research & Creative Works

Electron momentum spectroscopy (EMS) results are presented for the sulfur hexafluoride (SF6) molecule using a high-resolution binary (e, 2e) spectrometer at incident energies (Ei) of 600, 1200, and 2400 eV plus the binding energy. The valence orbital momentum profiles were measured with a binding energy resolution of 0.68 eV and angular resolutions of Δθ = ±0.6⁰, ΔΦ = ±0.85⁰. Whereas the two higher incident energies are in the range where normally EMS measurements do not exhibit an impact-energy dependence, the current experimental data display a dynamic dependence on the impact energies. The measured momentum profiles are compared with predictions from …