; Zhao, Qiang] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Zhao, Qiang] Chinese Acad Sci, Sci Facil, Ctr Theoret Phys, Beijing 100049, Peoples R China
In this work, we apply the vector meson dominance model to extract the electromagnetic timelike form factor of the D* -> D transition combining the recent Belle data for e(+)e(-) -> D*D-+(-) + c.c. and data for D* -> D gamma. Two solutions are obtained in the interpretation of the cross section lineshape: i) With a relatively large coupling for psi D*(D) over bar determined by experiment, destructive interferences among those charmonium components are required to bring down the overall cross sections, and then account for the cross section lineshape. ii) With a relatively small value for the psi D*(D) over bar coupling based on heavy quark theory, an apparent cross section deficit near threshold is observed, and contributions from other mechanisms are needed. It might imply the presence of an additional resonance X(3900). Meanwhile, we also point out that an enhancement like that could be produced by the D-s*(D) over bar (s) + c.c. open channel effects.