Binding Energy of Muonic Beryllium: Perturbative versus All--Order Calculations
Abstract
We compute the ground-state binding energy of muonic Be in two ways: first, the fully perturbative treatment of the nuclear-size effect often employed in light systems, and second, an approach that accounts for the finite-nuclear-size to all orders (and is inspired by calculations otherwise employed for heavy muonic ions). The results are compared term by term and show that both approaches agree to better than one part-per-million of the total energy. The objective of this work is twofold. The first is practical: to provide a parametrization that allows the extraction of the Be charge radius from recent and forthcoming experiments with high precision. The second is more conceptual: to act as a bridge between the community working on calculations for light systems and those focusing on heavy systems, demonstrating that the fully relativistic approach otherwise chosen for heavy systems can be enhanced to cover theoretical predictions for all charge numbers.
Keywords
Cite
@article{arxiv.2603.25278,
title = {Binding Energy of Muonic Beryllium: Perturbative versus All--Order Calculations},
author = {Shikha Rathi and Ulrich D. Jentschura and Paul Indelicato and Ben Ohayon},
journal= {arXiv preprint arXiv:2603.25278},
year = {2026}
}