On the nature of X(3960)

Abstract

A near-threshold enhancement in the D^{+}_{s}D^{-}_{s} system, dubbed as X(3960), is observed by the LHCb collaboration recently. A combined analysis on chi _{c0}(3930)~(rightarrow D^+ D^-), X(3960)~(rightarrow D^{+}_{s}D^{-}_{s}), and X(3915)~(rightarrow J/psi omega ) is performed using both a K-matrix approach of D_{(s)}bar{D}_{(s)} four-point contact interactions and a model of Flatté-like parameterizations. The use of the pole counting rule and spectral density function sum rule indicate, under current statistics, that this D^{+}_{s}D^{-}_{s} near-threshold state has probably the mixed nature of a cbar{c} confining state and D^{+}_{s}D^{-}_{s} continuum.