Resonance X(5568) as an exotic axial-vector state

The mass and meson-current coupling constant of the resonance X(5568), as well as the width of the decay X(5568) -> B-s*pi are calculated by modeling the exotic X(5568) resonance as a diquark-antidiquark state X-b = [su][bd] with quantum numbers J(P) = 1(+). The calculations are made employing QCD two-point sum rule method, where the quark, gluon and mixed vacuum condensates up to dimension eight are taken into account. The sum rule approach on the light-cone in its soft-meson approximation is used to explore the vertex XbBs*pi and extract the strong coupling g(XbBs*pi), which is a necessary ingredient to find the width of the X-b -> B-s*pi(+) decay process. The obtained predictions are compared with the experimental data of the D0 Collaboration, and results of other theoretical works.