Hidden-charm and radiative decays of theZ(4430)as a hadronicD1D¯*bound state

Abstract

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