Three-coupled-channel analysis of Zc(3900) involving DD¯*

Abstract

In this work, we conduct a three-coupled-channel analysis of the Zc(3900) structure, focusing on the DD¯*, J/ψπ, and ρηc channels, based on the one-boson exchange model. Drawing from previous study on the exotic state Tcc, we only utilize one more parameter to construct the interactions between the channels. Our model successfully reproduces the experimental line shapes of the invariant mass distribution at s=4.23 and 4.26 GeV for the three channels. Additionally, the finite-volume energy levels in our model show agreement with current lattice QCD conclusion. Detailed analysis suggests that the Zc(3900) peaks in the πJ/ψ and ρηc distributions primarily arise from the triangle loop involving the D1D¯D* intermediate system. In the DD¯* distribution, the threshold peak is generated by the cascade decay mechanism enhanced by a triangle diagram. Moreover, we find a virtual pole located far from the threshold, indicating that Zc(3900) peaks are not associated with a physical pole. We conclude that the Zc(3900) peaks are predominantly caused by the threshold cusp. Published by the American Physical Society 2024