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arXiv · 2110.07484

Effective range expansion for narrow near-threshold resonances

Vadim Baru·Xiang-Kun Dong·Meng-Lin Du·Arseniy Filin·Feng-Kun Guo·Christoph Hanhart·Alexey Nefediev·Juan Nieves·Qian Wang
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Abstract

We discuss some general features of the effective range expansion, the content of its parameters with respect to the nature of the pertinent near-threshold states and the necessary modifications in the presence of coupled channels, isospin violations and unstable constituents. As illustrative examples, we analyse the properties of the $χ_{c1}(3872)$ and $T_{cc}^+$ states supporting the claim that these exotic states have a predominantly molecular nature.

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Vadim Baru, Xiang-Kun Dong, Meng-Lin Du, Arseniy Filin, Feng-Kun Guo, Christoph Hanhart, Alexey Nefediev, Juan Nieves, Qian Wang. 2022-03-08. Effective range expansion for narrow near-threshold resonances. https://doi.org/10.1016/j.physletb.2022.137290

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