Two-pole structure of the

Abstract

We study the interaction of the Dπ, Dη and DsK̄ channels in JP = 0+ in the framework of unitarized chiral perturbation theory in finite volume, predicting the volume dependence of the energy levels. The results succesfully describe the energy levels provided in a recent lattice QCD calculation of the same system. We find two poles in the energy region of the resonance, with masses MeV and half-widths MeV respectively. We study their evolution in the light-flavor SU(3) limit, which allows us to identify the resonance and the pole with lower mass as partners of the same SU(3) multiplet. The mass of the higher pole is obtained between the Dη and DsK̄ threshold energies, strongly coupled to the latter channel, thus we expect it to influence the DsK̄ invariant mass distribution.