Lineshape of $e^{+}{e}^{-}\to D^{\ast }\bar{D}+c.c.$ and electromagnetic form factor of $D^{\ast }\to D$ transition in the time-like region

Abstract

In this work, we apply the vector meson dominance (VMD) model to extract the electromagnetic time-like form factor of the $D^{\ast }\to D$ transition combining the recent Belle data for $e^{+}{e}^{-}\to D^{\ast +}{D}^{-}+c.c.$ and data for $D^{\ast }\to D\gamma$. Two solutions are obtained in the interpretation of the cross section lineshape: i) With a relatively large coupling for $\psi D^{\ast }\bar{D}$ 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 $\psi D^{\ast }\bar{D}$ 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 $D_s^{\ast }\overline{D_s}+c.c.$ open channel effects.

arXiv commentRevtex, 11 pages, 4 figures; Revised version with minor changes, to appear in PRD.

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Cited by in corpus (7)

• Hadronic molecules
• Exclusive open-charm near-threshold cross sections in a coupled-channel approach
• Open charm effects in $e^{+}{e}^{-}\to J/\psi \eta$, $J/\psi {\pi }^0$ and $\varphi {\eta }_c$
• $P$-wave coupled channel effects in electron-positron annihilation
• Charm rescattering in $B^0\to K^0\bar{\ell }\ell$: an improved analysis
• Resonance parameters of the vector charmoniumlike state $G(3900)$
• Open charm scenarios