Dynamics study of $Z^+(4430)$ and X(3872) in molecular picture

TL;DR

This study investigates the molecular nature of exotic states Z(4430) and X(3872), finding they cannot be explained as simple molecular states with pion and sigma exchanges, but predicts a new bound state in the B meson system.

Contribution

The paper provides a detailed dynamical analysis of Z(4430) and X(3872), introducing the necessity of additional exchange potentials and predicting a new B meson bound state.

Findings

Z(4430) cannot be explained as a D1'D* or D1D* molecular state with only pion exchange.

X(3872) is unlikely to be a DD* molecular state with pion and sigma exchanges.

A potential S-wave BB* bound state with J^{PC}=1^{++} is predicted.

Abstract

In this talk, we review our recent work about the dynamical studies of $Z^+(4430)$ and X(3872). $Z^+(4430)$ can not be explained as a $D_1'D^*$ or $D_1D^*$ molecular state only considering one pion exchange potential without the cutoff, which needs to be confirmed by introducing sigma exchange potential and adding the cutoff in the effective potential. One also excludes the possibility of X(3872) as a $DD^*$ molecular state by one pion and one sigma exchanges with the cutoff. Fortunately there exists an S-wave $BB^*$ bound state with $J^{PC}=1^{++}$. we suggest future experiment to search this state.