Can X(5568) be a tetraquark state?

Very recently, the D0 collaboration has reported the observation of a narrow structure, X(5568), in the decay process X(5568) → B sπ using the 10.4fb−1 data of pp̄ collision at √ s = 1.96 TeV. This structure is of great interest since it is the first hadronic state with four different valence quark flavors, b, s, u, d. In this work, we present a tetraquark interpretation of the X(5568). Based on the diquarkantidiquark scheme, we study the spectroscopy of the tetraquarks with one heavy bottom/charm quark and three light quarks. We find that the lowest-lying S-wave state, a tetraquark with the flavor [su][b̄d̄] and the spin-parity J = 0, is about 150 MeV higher than the X(5568). It is still likely to identify the X(5568) as a tetraquark with J = 0 when the systematic errors in the model are considered. Further detailed experimental and theoretical studies of the spectrum, production and decays of the X(5568) in the future are severely needed towards a better understanding its nature and the classification of hadron exotic states.