Hidden-charm and radiative decays of the Z(4430) as a hadronic D_1 \bar{D^\ast} bound state

TL;DR

This paper models the Z(4430) as a hadronic molecule of D* and D1 mesons, predicting decay widths and radiative properties that align with experimental observations and suggest detectable signals in future experiments.

Contribution

It introduces a hadronic molecule interpretation of Z(4430) and provides decay width predictions using a phenomenological Lagrangian approach, offering new insights into its structure.

Findings

The $ o \pi^\pm\psi^\prime$ decay dominates over $ o \pi^\pm\psi$ despite phase space differences.

The radiative decay width $ o \pi^\pm\gamma$ is sizable, indicating potential for experimental detection.

Predictions are qualitatively consistent with experimental data on Z(4430) decays.

Abstract

We study the $Z^\pm(4430)$ meson within a heavy hadron molecule interpretation where the $Z$ is considered as a bound state of a vector $D^\ast(2010)$ and an axial-vector $D_1(2420)$. We give predictions for the strong hidden-charm $Z^\pm(4430) \to \pi^\pm \psi$ and $\pi^\pm\psi^\prime$ decay widths and also study the radiative $Z^\pm\;(J^P=1^-) \to \pi^\pm\gamma$ decay properties in a phenomenological Lagrangian approach. Our findings are qualitatively in line with the experimental observation that the $\pi^\pm\psi^\prime$ transition dominates over the $\pi^\pm\psi$ decay mode despite a smaller phase space. The width for the radiative mode $\pi^\pm\gamma$ is sizable, allowing possible detection in future experiments.