1. Mesons can form exotic atoms when they interact with nuclei due to the Coulomb interaction.
2. The eta meson has an attractive strong interaction with nucleons, which could lead to the formation of unstable bound states of eta mesons and nuclei.
3. Experiments have been conducted to explore the eta–nucleus interaction in the final states, and theoretical models have been developed to understand the basic eta–nucleon interaction.
This article is a comprehensive overview of the research on the interaction of eta mesons with nuclei, providing a detailed description of both experimental and theoretical developments in this field over the past 25 years. The article is well-written and provides a clear explanation of its subject matter, making it easy for readers to understand. The article does not appear to be biased or one-sided in its reporting, as it presents both sides equally and does not make any unsupported claims or omit any counterarguments. Additionally, there are no promotional elements present in the article, nor does it present any risks without noting them. All in all, this article appears to be reliable and trustworthy in its content and presentation.