QCD Sum-Rule Interpretation of X(3872) with $J^{PC}=1^{++}$ Mixtures of Hybrid Charmonium and $\bar D D^*$ Molecular Currents

TL;DR

This paper uses QCD sum-rules to explore whether the X(3872) particle can be modeled as a mixture of hybrid charmonium and molecular states, finding that a mixed model aligns well with observed mass.

Contribution

The study introduces a mixed current approach in QCD sum-rules to analyze the X(3872), providing a more robust description than pure molecular models.

Findings

Mixed model predicts mass in agreement with X(3872)

Increasing mixing parameter raises predicted mass

Mixed sum-rule analysis is more stable than pure molecular case

Abstract

QCD sum-rules are employed to determine whether the X(3872) can be described as a mixed state that couples to $J^{PC}=1^{++}$ charmonium hybrid and $\bar D D^*$ molecular currents. After calculating the mixed correlator of hybrid and molecular currents, we formulate the sum-rule in terms of a mixing parameter that interpolates between the pure molecular and hybrid scenarios. As the mixing parameter is increased from the pure molecular case, the predicted mass increases until it reaches a maximum value in good agreement with the X(3872) and the resulting sum-rule analysis appears more robust than the pure molecular case.