To date, the nature of $Z_c(3900)/Z_c(4025)$ is not clear. In this work, we propose to study the internal structure of $Z_c(3900)/Z_c(4025)$ by exploring the charmless decays. Compared to charmed decays, charmless decay channels may play a unique role since they request the annihilation of the heavy constituents. We calculate the decay width for $Z_c(3900)/Z_c(4025)\to VP$, where $P$ and $V$ denote the pseudoscalar and light vector meson, respectively. Here, the $Z_c(3900)$ and $Z_c(4025)$ are the molecular states of $D^{*}\overline{D}$ and $D^{*}{\overline{D}}^{*}$. The decay process occurs through intermediate $D{D}^{*}/D^{*}{D}^{*}$ meson loops. Based on an effective Lagrangian, we obtain sizable predictions for the branching ratios, which are accessible in experiments. The experimental measurements in the future will not only shed light on the decay mechanism but will also lead to a deeper understanding of the mysterious structure of the $Z_c(3900)/Z_c(4025)$.

• Received 16 May 2016

DOI:https://doi.org/10.1103/PhysRevD.94.014015