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arXiv · 2211.03508

A coupled-channel system with anomalous thresholds and unitarity

Csaba L. Korpa·Matthias F. M. Lutz·Xiao-Yu Guo·Yonggoo Heo
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Abstract

We consider the isospin one-half example system, with $D \,\pi , D\,\eta, D_s \bar K, D^* \pi , D^*\eta, D^*\bar K$ coupled channels in the $J^P = 1^-$ partial wave, chosen such that various phenomena that come with the opening of an anomalous threshold can be illustrated in a step-wise procedure by a suitable variation of up, down and strange quark masses. We use a set of LEC in the chiral Lagrangian that were adjusted to a large set of Lattice QCD results. The six phase shifts and inelasticity parameters are presented for various choices of the pion mass. For a pion mass of 150 MeV there are no anomalous thresholds encountered. The small change from 150 MeV to 145 MeV pion mass causes a dramatic impact of the anomalous threshold on the phase shifts.

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Csaba L. Korpa, Matthias F. M. Lutz, Xiao-Yu Guo, Yonggoo Heo. 2022-11-07. A coupled-channel system with anomalous thresholds and unitarity. https://doi.org/10.1103/physrevd.107.l031505

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