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 ${\chi }_{c0}(3930)(\to D^{+}{D}^{-})$, $X(3960)(\to D_s^{+}{D}_s^{-})$, and $X(3915)(\to J/\psi \omega )$ 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 $c\bar{c}$ confining state and $D_s^{+}{D}_s^{-}$ continuum.

Comments: 8 pages, 4 figures, 5 tables