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arXiv · 2211.02083

Methods on compositeness and related aspects

J. A. Oller
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Abstract

In many physical applications, bound states and/or resonances are observed, which raises the question whether these states are elementary or composite. Here we elaborate on several methods for calculating the compositeness $X$ of bound states and resonances in Quantum Mechanics, and in Quantum Field Theory by introducing particle number operators. For resonances $X$ is typically complex and we discuss how to get meaningful results by using certain phase transformations in the $S$ matrix.

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J. A. Oller. 2022-11-03. Methods on compositeness and related aspects. https://doi.org/10.1051/epjconf/202227403017

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