Positron annihilation and binding in aromatic and other ring molecules

• URL: http://arxiv.org/abs/2312.02779v1
• Date: Tue, 5 Dec 2023 14:11:30 GMT
• Title: Positron annihilation and binding in aromatic and other ring molecules
• Authors: E. Arthur-Baidoo, J. R. Danielson, C. M. Surko, J. P. Cassidy, S. K. Gregg, J. Hofierka, B. Cunningham, C. H. Patterson and D. G. Green
• Abstract summary: Annihilation spectra are presented for aromatic and heterocyclic ring molecules resolved as a function of incident positron energy. Good to excellent agreement is found between the measured binding energies and the predictions of an textitab initio many-body theory.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Annihilation spectra are presented for aromatic and heterocyclic ring molecules resolved as a function of incident positron energy using a trap-based positron beam. Comparisons with the vibrational mode spectra yield positron-molecule binding energies. Good to excellent agreement is found between the measured binding energies and the predictions of an \textit{ab initio} many-body theory that takes proper account of electron-positron correlations including virtual-positronium formation. The calculations elucidate the competition between permanent dipole moments and $\pi$ bonds in determining the spatial distribution of the bound-state positron density. The implications of these results and the role of multimode features in annihilation in these molecules, including Fermi resonances, are discussed.

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