• Zc(3900) as a D ¯D∗ Molecule from Pole Counting Rule

    分类: 物理学 >> 核物理学 提交时间: 2016-09-02

    摘要: A careful study on the nature of the Z_c(3900) resonant structure is carried out in this work. By constructing the pertinent effective Lagrangians and considering the important final-state-interaction effects, we first give a unified description to all the relevant experimental data available, including the J/\psi\pi and \pi\pi invariant mass distributions from the e^+e^-\to J/\psi\pi\pi process, the h_c\pi distribution from e^+e^-\to h_c\pi\pi and also the D\bar{D}^{*} spectrum in the e^+e^-\to D\bar{D}^{*}\pi process. After fitting the unknown parameters to the previous data, we search the pole in the complex energy plane and only find one pole in the nearby energy region in different Riemann sheets. Therefore we conclude that Z_c(3900) is of D\bar{D}^* molecular nature, according to the pole counting rule method. We emphasize that the conclusion based upon pole counting method is not trivial, since both the D\bar{D}^{*} contact interactions and the explicit Z_c exchanges are introduced in our analyses and they lead to the same conclusion.