Dissertation/Thesis Abstract

Threshold resonances in atomic three-body systems
by Diaz, Daniel Cipriano, M.S., California State University, Long Beach, 2016, 52; 10142970
Abstract (Summary)

Atomic resonances present a difficult chapter in the study of atomic structure. The calculation and measurement of these resonant states have provided a challenge for both theorists and experimentalists. This work focuses on the numerical calculation of the resonant states. Some years ago a method to calculate the resonant states of three-body atomic interactions was developed. This method involves solving the Faddeev equations using a Merkuriev cut and a Coulomb-Sturmian basis, and will be the method used for the calculations in this work. This method was used as an alternative to the more conventional methods of calculating atomic resonant states. At the time of its derivation, the method was used to calculate the narrow-width resonances of the electron-Positronium (e – Ps) system, which showed accurate results with respect to the calculations done by other groups using alternative methods. Additionally, the method saw an emergence of resonances (broad-width) which line-up to the system thresholds. We have come to call these broad-width resonances the threshold resonances. However, at the time, these threshold resonances proved too computationally intensive to make confident results. Now, with the assistance of better computational resources and an improved code, this problem is again addressed.

New calculations of the narrow-width and threshold resonances were completed which support the appearance of the threshold resonances in the e – Ps system. The threshold resonances were observed lining up at the first, second, and third two-body thresholds, a trend that is assumed to continue at even higher energies. Calculations were carried out for both the 1S and 3S states. After successfully making calculations of the e – Ps system resonant states, calculations were also carried out for the electron-Hydrogen (e–H) 1S and 3S resonances. The calculations for the e – H system were carried out for the threshold resonances emerging from the 1st threshold. Additionally, we propose an explanation for the emergence of the threshold resonances.

Indexing (document details)
Advisor: Papp, Zoltan
Commitee: Jaikumar, Prashanth, Kwon, Chuhee
School: California State University, Long Beach
Department: Physics and Astronomy
School Location: United States -- California
Source: MAI 55/06M(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Atoms & subatomic particles, Theoretical physics
Keywords: Atomic resonances, Faddeev equations, Merkuriev, Resonances, Three-body coulomb systems, Threshold
Publication Number: 10142970
ISBN: 978-1-339-98224-3
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