Hadronic molecule model for the doubly charmed state $T^{+}_{cc}$

Abstract

The mass, current coupling, and width of the doubly charmed four-quark meson $T_{cc}^{+}$ are explored by treating it as a hadronic molecule $ M_{cc}^{+}\equiv D^{0}D^{\ast +}$. The mass and current coupling of this molecule are calculated using the QCD two-point sum rule method by including into analysis contributions of various vacuum condensates up to dimension $ 10 $. The prediction for the mass $m=(4060\pm 130)~\mathrm{MeV}$ exceeds the two-meson $D^{0}D^{\ast +}$ threshold $3875.1~\mathrm{MeV}$, which makes decay of the molecule $M_{cc}^{+}$ to a pair of conventional mesons $ D^{0}D^{\ast +}$ kinematically allowed process. The strong coupling $G $ of particles at the vertex $M_{cc}^{+}D^{0}D^{\ast +}$ is found by applying the QCD three-point sum rule approach, and used to evaluate the width of the decay $M_{cc}^{+} \to D^{0}D^{\ast +}$. Obtained result for the width $ \Gamma=(3.8\pm 1.7)~\mathrm{MeV}$ demonstrates that $M_{cc}^{+}$ is wider than the resonance $T_{cc}^{+}$.