The strange partner of the Zc structures in a coupled-channels model

The discovery of a new charged structure in the K+ recoil-mass spectrum near the Ds-D*(0)/D-s*-D-0 threshold, dubbed Z(cs)(3985)(-), reinforce the idea that the structure of hadrons goes beyond the naive qqq and the q (q) over bar structures. The existence of this state, with quark content c (c) over bars (u) over bar, can be expected from the well-established Z(c)(3900)+/- and Z(c)(4020) states using SU(3) flavor symmetry. The Z(c) structures have been explained using the chiral constituent quark model in a coupled-channels calculation and, in this work, we undertake the study of the Z(cs)(3985)(-) using the same model. We are able to reproduce the K+ recoil-mass spectrum without any fine tuning of the model parameters. The study of the analytical structure of the S-matrix allows us to conclude that the structure is due to the presence of one virtual pole. A second state, the SU(3) flavor partner of the Z(c)(4020) is predicted at similar to 4110 MeV/c(2). New states in the hidden bottom strange sector are also predicted. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The discovery of the Z(cs)(3985)(-) structure expands the theory of hadron structures beyond traditional models. The existence of Z(cs)(3985)(-) can be predicted using SU(3) flavor symmetry. The analytical structure of the S-matrix analysis confirms that the structure is due to the presence of a virtual pole.