通过光生过程揭示新观测到的 $η_1(1855)$ 的内部结构
Revealing the inner structure of the newly observed $η_1(1855)$ via photoproduction
AI总结：
本文通过结合 Regge 化模型与矢量介子主导模型研究 $η_1(1855)$ 的光生过程，利用总截面和线形差异区分其分子态与混合介子解释，并提出可在 GlueX 及中国电子离子对撞机中检验。
摘要：
最近，BESIII 合作组在 $ηη^{'}$ 的不变质量谱中观测到一个新的强子奇特态 $η_1(1855)$。根据其谱学性质和衰变宽度等特征，$η_1(1855)$ 被建议可能是紧致的多夸克态、强子分子态或混合介子。为了区分对 $η_1(1855)$ 的不同解释，本文提出了一种将 Regge 化模型与矢量介子主导模型相结合的方法，用于研究质子靶上 $η_1(1855)$ 的光生过程。如果 $η_1(1855)$ 是 $s\ar{s}g$ 混合介子，则 $η_1(1855)$ 可以通过 Primakoff 效应产生。然而，若假设 $η_1(1855)$ 为 $S$ 波 $K\ar{K}_1(1400)$ 分子态，则 $η_1(1855)$ 的光生过程由 $t$ 道矢量介子 $ρ$、$ω$ 和 $ϕ$ 交换主导。我们的计算表明，通过 $γp$ 反应产生 $η_1(1855)$ 的总截面最高可达 0.115 pb，约为将 $η_1(1855)$ 视为 $S$ 波 $K\ar{K}_1(1400)$ 分子态时所获得总截面的 0.0124$\%$。我们还发现它们的线形存在显著差异。如果 $η_1(1855)$ 是分子态，则 $η_1(1855)$ 在阈值附近的光生过程为检验其分子本质提供了一个很好的场所。然而，如果 $η_1(1855)$ 是 $s\ar{s}g$ 混合介子，则最好在更高能量下，至少在 $E_γ=16.97$ GeV 以上，观测 $η_1(1855)$ 的产生。这些结果可以在 GlueX 实验或中国的电子离子对撞机中进行测量，以检验 $η_1(1855)$ 的本质。
英文摘要：
Very recently, a new hadronic exotic state $η_1(1855)$ at the invariant mass spectrum of $ηη^{'}$ was observed by the BESIII Collaboration. According to its properties, such as the spectroscopy and decay width, the $η_1(1855)$ have been suggested to be a compact multi-quark state, a hadron molecule, or a hybrid meson. In order to distinguish the various interpretations of the $η_1(1855)$, a Reggeized model combined with the vector dominance model for $η_1(1855)$ photoproduction on the proton target is presented. If the $η_1(1855)$ is a $s\bar{s}g$ hybrid meson, the $η_1(1855)$ can be produced though the Primakoff effect. However, the $η_1(1855)$ photoproduction is dominated by the $t$-channel vector mesons $ρ$, $ω$, and $ϕ$ exchange by assuming $η_1(1855)$ as an $S$-wave $K\bar{K}_1(1400)$ molecular state. Our calculations show that the total cross section of the $η_1(1855)$ production via $γp$ reaction can reach up to 0.115 pb, about 0.0124$\%$ of the total cross section obtained by considering the $η_1(1855)$ as an $S$-wave $K\bar{K}_1(1400)$ molecule. We also find their line shapes are sizably different. If the $η_1(1855)$ is a molecular state, the photoproduction of $η_1(1855)$ near the threshold offers a nice place to test its molecular nature. However, it should be better to take high energy, at least above $E_γ=16.97$ GeV, to observe the production of $η_1(1855)$ if $η_1(1855)$ is a $s\bar{s}g$ hybrid meson. These results can be measured in the GlueX experiment or Electron-Ion Collider in China to test the nature of the $η_1(1855)$.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
