Charmed partner of the exotic $X(5568)$ state and its properties

Abstract

The mass, decay constant and width of a hypothetical charmed partner $X_c$ of the newly observed exotic $X_b(5568)$ state are calculated using a technique of QCD sum rule method. The $X_c=[su][\overline{c}\overline{d}]$ state with $J^P=0^{+}$ is described employing two types of the diquark-antidiquark interpolating currents. The evaluation of the mass $m_{X_c}$ and decay constant $f_{X_c}$ is carried out utilizing the two-point sum rule method by including vacuum condensates up to eight dimensions. The widths of the decay channels $X_c\to D_s^{-}{\pi }^{+}$ and $X_c\to D^0{K}^0$ are also found. To this end, the strong couplings $g_{X_c{D}_s\pi }$ and $g_{X_{c}DK}$ are computed by means of QCD sum rules on the light-cone and soft-meson approximation.

Comments: 7 Pages, 2 Figures and 3 Tables