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

Abstract

The discovery of a new charged structure in the K+ recoil-mass spectrum near the Ds−D⁎0/Ds⁎−D0 threshold, dubbed Zcs(3985)−, reinforce the idea that the structure of hadrons goes beyond the naive qqq and the qq¯ structures.The existence of this state, with quark content cc¯su¯, can be expected from the well-established Zc(3900)± and Zc(4020) states using SU(3) flavor symmetry. The Zc 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 Zcs(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 Zc(4020) is predicted at ∼4110 MeV/c2. New states in the hidden bottom strange sector are also predicted.