X(3872) as a molecular DD* state in a potential model

TL;DR

This paper investigates whether the X(3872) particle can be modeled as a molecular bound state of D and D* mesons using a potential derived from meson exchange, considering isospin breaking and different quantum states.

Contribution

It introduces a potential model based on heavy hadron chiral perturbation theory to describe the X(3872) as a DD* bound state, including charged, neutral, and isospin breaking effects.

Findings

X(3872) can be described as a DD* bound state with J(PC)=1(++) at reasonable parameters.

Binding is possible in the BB* system in the isoscalar limit for J(PC)=1(++) or 1(+-).

The model supports the molecular interpretation of X(3872).

Abstract

We discuss the possibility that the X(3872) can be a hadronic DD* bound state in the framework of a potential model. The potential is generated by the exchange of pseudoscalar, scalar and vector mesons resulting from the Lagrangian of heavy hadron chiral perturbation theory. The hadronic bound state configuration contains charged and neutral DD* components, while orbital S- and D-waves are included. Isospin symmetry breaking effects are fully taken into account. We show that binding in the DD* system with J(PC)=1(++) already exists for a reasonable value of the meson-exchange regularization parameter of Lambda around 1.2 GeV. We also explore the possibility of hadronic BB* bound states and show that binding can be achieved in the isoscalar limit for J(PC)=1(++) or 1(+-).