$Z_c(3900)$ as a resonance from the $D\bar{D}^*$ interaction

Understand

In this paper it is proposed that the charged charmonium-like state $Z_c(3900)$ is a resonance above the threshold from the $D\bar{D}^*$ interaction.

• The $D\bar{D}^*$ interaction is described by the one-boson exchange model with light meson exchanges plus a short-range $J/\psi$ exchange.
• The scattering amplitude is calculated within a Bethe-Salpeter equation approach and the poles near the $D\bar{D}^*$ threshold are searched.
• In the isoscalar sector, two poles found under the $D\bar{D}^*$ threshold, i.e., bound states, have the quantum numbers $I^G(J^{PC})=0^-(1^{+-})$ and $0^+(1^{++})$.