Investigations of charmless decays of X(3872) via intermediate meson loops

Abstract

The charmless decay processes of $X(3872)$ provide us a good platform to study the nature and the decay mechanism of $X(3872)$. Based on a molecular nature of $X(3872)$ as a $\overline{D}{D}^{*}$ bound state, we have investigated the charmless decays $X(3872)\ensuremath{\rightarrow}VV$ and $VP$ via intermediate ${D}^{*}\overline{D}+\mathrm{c}.\mathrm{c}.$ meson loops, where $V$ and $P$ stand for light vector and pseudoscalar mesons, respectively. We discuss three cases, i.e., pure neutral components ($\ensuremath{\theta}=0$), isospin singlet ($\ensuremath{\theta}=\ensuremath{\pi}/4$) and neutral components dominant ($\ensuremath{\theta}=\ensuremath{\pi}/6$), where $\ensuremath{\theta}$ is a phase angle describing the proportion of neutral and charged constituents. The proportion of neutral and charged constituent has an influence on the decay widths of $X(3872)\ensuremath{\rightarrow}VV$ and $VP$. With the coupling constant of $X(3872)$ to the $\overline{D}{D}^{*}$ channel obtained under the molecule ansatz of $X(3872)$ resonance, the predicted decay widths of $X(3872)\ensuremath{\rightarrow}VV$ are about tens of keVs, while the decay width can reach a few hundreds of keVs for $X(3872)\ensuremath{\rightarrow}VP$. The dependence of these ratios between different decay modes of $X(3872)\ensuremath{\rightarrow}VV$ and $X(3872)\ensuremath{\rightarrow}VP$ to the mixing angle $\ensuremath{\theta}$ is also investigated. It is expected that the theoretical calculations here can be tested by future experiments.