Resonance parameters of the vector charmoniumlike state $G(3900)$

Abstract

Motivated by the updated analysis of the $G(3900)$ by the BESIII collaboration, we perform a global analysis of the cross sections of the $e^{+}{e}^{-}\to D\bar{D}$, $e^{+}{e}^{-}\to D{\bar{D}}^{\ast }+c.c.$, $e^{+}{e}^{-}\to D^{\ast }{\bar{D}}^{\ast }$ processes, especially focusing on the properties of the $G(3900)$. As the energy region of interest is limited by the next opening threshold, i.e. the $D_1\bar{D}$ threshold, we focus on the energy region $[3.7,4.25]\mathrm{GeV}$, where three charmonia $\psi (1D)$, $\psi (3S)$ and $\psi (2D)$ explicitly contribute to the cross sections. By constructing the $P$-wave contact interaction between the $(D,D^{\ast })$ doublet and its antiparticle in the heavy quark limit, we extract the physical scattering amplitude by solving the Lippmann-Schwinger equation. No matter whether three or two charmonium states are included in our framework, we always find a dynamically generated state corresponding to the $G(3900)$, which suggests it to be a $P$-wave dynamically generated state. We also predict several dynamically generated states in the corresponding $1^{-+}$ channel. These states can be further searched for in the electron-positron annihilation process involving the emission of a single photon.

Comments: 25 pages, 11 figures