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 the technique of the QCD sum rule method. The X-c = [su][(c) over bar(d) over bar] state with J(P) = 0(+) is described, employing two types of the diquark-antidiquark interpolating currents. The evaluation of the mass m(Xc) and decay constant f(Xc) 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 -> D-s(-)pi(+) and X-c -> (DK0)-K-0 are also found. To this end, the strong couplings g(XcDs pi) and g(XcDK) are computed by means of QCD sum rules on the light-cone and soft-meson approximation.