AI 中文总结
本文基于核谱函数的碰撞模型，通过计算不同情景下$X(6900)$的相关观测值，探究全粲四夸克态$X(6900)$的本质，为后续实验确定其内部结构提供理论依据。
AI 中文摘要
本文基于核谱函数的碰撞模型，研究了在运动学阈值附近通过原子核的遍在光生过程探究全粲四夸克态$X(6900)$本质的可能性。该模型涵盖了$X(6900)$在直接光子-核子相互作用中的产生过程，以及其内部结构的三种不同情景：紧凑四夸克态、由两个隐粲介子$J/\boldsymbol{\text{ψ}}$和$\boldsymbol{\text{ψ}}(3770)$构成的分子态，以及前两者的混合态。我们在上述情景下，计算了$^{12}\text{C}$和$^{184}\text{W}$原子核在30-40 GeV近阈值光子能量下的绝对与相对激发函数、实验室极角为$0^\text{\boldsymbol{\text{°}}}$-5$^\text{\boldsymbol{\text{°}}}$且光子能量为35 GeV时，这些靶核产生$X(6900)$介子的绝对动量微分截面及其比值，以及光子能量为35 GeV时$X(6900)$ transparency ratio的A依赖关系。研究表明，这些观测值对$X(6900)$的内在结构具有明确的敏感性，因此可通过将其与未来实验设施（如计划中的美国和中国电子离子对撞机）的实验数据进行对比，用于确定$X(6900)$的内部结构。
英文摘要
The possibility to study the nature of fully-charmed tetraquark state $X(6900)$ from its inclusive photoproduction off nuclei near the kinematic threshold is investigated within the collision model based on the nuclear spectral function. The model accounts for $X(6900)$ production in direct photon--nucleon interactions as well as three different scenarios for its internal structure: compact tetraquark, molecule of the two hidden-charm $J/ψ$ and $ψ(3770)$ mesons and the mixture of both of them. We calculate within these scenarios the absolute and relative excitation functions on $^{12}$C and $^{184}$W nuclei at near-threshold photon energies of 30--40 GeV, the absolute momentum differential cross sections and ratios of them for the $X(6900)$ meson production off these target nuclei at laboratory polar angles of 0$^{\circ}$--5$^{\circ}$ and for photon energy of 35 GeV as well as the A-dependences of its transparency ratios at photon energy of 35 GeV. We show that these observables reveal a definite sensitivity to the $X(6900)$ intrinsic structure. Therefore, they might be useful for the determination of this structure from the comparison of them with the experimental data from the future experiments at the upcoming experimental facilities, such as the planned electron-ion colliders in the United States and China.
Comments21 pages, 9 figures
