Theoretical interpretation of the Ξ(1620) and Ξ(1690) resonances seen in Ξ_c⁺ → Ξ^- π⁺ π⁺ decay

2023/08/23 by Li, Hai-Peng, Zhang, Gong-Jie, Liang, Wei-Hong +1
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.2308.11879

Abstract

We study the Belle reaction Ξ_c⁺ → Ξ^- π⁺ π⁺ looking at the mass distribution of π⁺ Ξ, where clear signals for the Ξ(1620) and Ξ(1690) resonances are seen. These two resonances are generated dynamically from the interaction in coupled channels of πΞ, K Λ, K Σ and ηΞ within the chiral unitary approach. Yet, the weak decay process at the quark level, together with the hadronization to produce pairs of mesons, does not produce the ππΞ final state. In order to produce this state one must make transitions from the K Λ, K Σ and ηΞ components to πΞ, and this interaction is what produces the resonances. So, the reaction offers a good test for the molecular picture of these resonances. Adding the contribution of the Ξ^*(1530) and some background we are able to get a good reproduction of the mass distribution showing the signatures of the two resonances as found in the experiment.

Related

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