Gamow shell model description of exceptional point in $^7$Li
Nuclear Theory
2025-12-09 v1
Abstract
We report the first identification of an exceptional point (EP) within the Gamow Shell Model in the Coupled Channels representation (GSM-CC). In the spectrum of Li, an EP is found for the doublet, where the two states coalesce in both energy and width, the phase rigidity vanishes, and the S-matrix develops a double pole. These features manifest directly in observables: the elastic cross section acquires a split-peak structure, and the phase shift shows a single jump. This work demonstrates that GSM-CC provides a powerful framework to explore EP phenomena in nuclei and their experimental signatures.
Keywords
Cite
@article{arxiv.2510.01928,
title = {Gamow shell model description of exceptional point in $^7$Li},
author = {David Cardona Ochoa and Marek Płoszajczak and Nicolas Michel},
journal= {arXiv preprint arXiv:2510.01928},
year = {2025}
}