Modeling the resonance $T_{cs0}^a(2900{)}^{++}$ as a hadronic molecule $D^{\ast +}{K}^{\ast +}$

Abstract

The doubly charged scalar resonance $T_{cs0}^a(2900{)}^{++}$ is studied in the context of the hadronic molecule model. We consider $T_{cs0}^a(2900{)}^{++}$ as a molecule $M=D^{\ast +}{K}^{\ast +}$ composed of vector mesons, and calculate its mass, current coupling and full width. The spectroscopic parameters of $M$, i.e., its mass and current coupling, are found by means of the QCD two-point sum rule method by taking into account vacuum expectation values of quark, gluon and mixed operators up to dimension $10$. The width of the molecule $M$ is evaluated through the calculations of the partial widths of the decay channels $M\to D_s^{+}{\pi }^{+}$, $M\to D_s^{\ast +}{\rho }^{+}$, and $M\to D^{\ast +}{K}^{\ast +}$. Partial widths of these processes are determined by strong couplings $g_1$, $g_2$, and $g_3$ of particles at vertices $M{D}_s^{+}{\pi }^{+}$, $M{D}_s^{\ast +}{\rho }^{+}$, and $M{D}^{\ast +}{K}^{\ast +}$ , respectively. We calculate the couplings $g_i$ by employing the QCD light-cone sum rule approach and technical tools of the soft-meson approximation. Predictions obtained for the mass $m=(2924\pm 107)\mathrm{MeV}$ and width $\Gamma =(123\pm 25)\mathrm{MeV}$ of the hadronic molecule $M$ allow us to consider it as a possible candidate of the resonance $T_{cs0}^a(2900{)}^{++}$.

Comments: 12 Pages, 3 Figures and 1 Table