Coupled-channel model for charmonium levels and an option for X(3872) -: art. no. 034010

The effects of charmed meson loops on the spectrum of charmonium are considered, with special attention paid to the levels above open-charm threshold. It is found that the coupling to charmed mesons generates a structure at the D (D) over bar (*) threshold in the 1(++) partial wave. The implications for the nature of the X(3872) state are discussed.