https://doi.org/10.1140/epjd/s10053-021-00330-1
Regular Article – Atomic Physics
s-Wave resonance in exponential cosine screened Coulomb potential
1
College of Physics, Jilin University, 130012, Changchun, People’s Republic of China
2
Institute of Atomic and Molecular Physics, Jilin University, 130012, Changchun, People’s Republic of China
3
Chemistry Program, Centre College, 40422, Danville, KY, USA
4
Institute of Atomic and Molecular Sciences, Academia Sinica, 10617, Taipei, Taiwan
Received:
6
October
2021
Accepted:
13
December
2021
Published online:
24
December
2021
The s-wave resonance in the exponential cosine screened Coulomb potential is investigated by employing the uniform complex-scaling generalized pseudospectral method. It is found that beyond the well-known critical screening parameter 
where the ground state merges into the continuum, there exists a huge gap for the screening parameter before the ground state transforms into a well-defined shape resonance lying above the autoionization threshold. The critical value for the emergence of such a shape resonance is determined at about 
. The behavior of the system in the gap 
is still a mystery, and it is conjectured that the bound state would probably transform into negative-energy virtual states and below-threshold shape resonances. For screening parameters larger than 
, the resonance positions and widths are calculated with high precision and the results are comparable to previous predictions available in the literature. The trajectories of the poles of S-matrix in both the complex energy and momentum planes are obtained.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021
