arXiv 2102.130582021-02hep-phhep-exhep-latnucl-th

重强子分子的轴向介子交换和$Z_c(3900)$和$Z_{cs}(3985)$共振

Axial meson exchange and the $Z_c(3900)$ and $Z_{cs}(3985)$ resonances as heavy hadron molecules

Mao-Jun Yan, Fang-Zheng Peng, Mario Sánchez Sánchez, Manuel Pavon Valderrama

备注：: 26 pages, 3 figures, 6 tables; tries to explain a few features of the Zc(3900), Zcs(3985) and Pcs(4459); corresponds to the published version
发表信息：: Phys. Rev. D 104, 114025 (2021)
DOI：: 10.1103/PhysRevD.104.114025

摘要：

早期关于重强子分子存在的推测是基于这样的想法，即光介子交换力可以导致束缚。与氘核类似，通常考虑的轻介子包括π介子、σ介子、ρ介子和Ω介子，但不包括轴介子$a_1(1260)$。虽然过去有人认为轴介子与核子的耦合确实很强，但它的质量比矢量介子重得多，因此它的交换最终被抑制。然而，这是不一定的情况下，在重强子分子：我们发现，即使从轴介子的贡献是适度的结合，它不能被忽略的矢量扇区矢量介子交换抵消。这可能为$Z_c(3900)$、$Z_c(4020)$或最近观察到的$Z_{cs}(3985)$等分子候选物提供天然结合机制。然而，$Z_{cs}(3985)$更依赖于不同因素的混合，其中（除了轴向介子交换）包括$η$交换和标量介子交换的性质。它们一起指向两个$Z_{cs}(3985)$ -类共振的存在，而不是一个，而在$Z_{cs}(3985)$标量介子交换的作用的意见可能是相关的$P_{cs}(4459)$。最后，轴向介子交换和味对称性破缺效应的结合表明，等矢量$J^{PC} = 0^{++}$ $D^*\bar{D}^*$和奇怪的$J^P = 2^{+}$ $D^*\bar{D}_s^*$分子是最有吸引力的配置，因此最有可能的分子伙伴的$Z_c(3900)$，$Z_c(4020)$和$Z_{cs}(3985)$。

英文摘要：

Early speculations about the existence of heavy hadron molecules were grounded on the idea that light-meson exchanges forces could lead to binding. In analogy to the deuteron, the light-mesons usually considered include the pion, sigma, rho and omega, but not the axial meson $a_1(1260)$. Though it has been argued in the past that the coupling of the axial meson to the nucleons is indeed strong, its mass is considerably heavier than that of the vector mesons and thus its exchange ends up being suppressed. Yet, this is not necessarily the case in heavy hadrons molecules: we find that even though the contribution to binding from the axial meson is modest, it cannot be neglected in the isovector sector where vector meson exchange cancels out. This might provide a natural binding mechanism for molecular candidates such as the $Z_c(3900)$, $Z_c(4020)$ or the more recently observed $Z_{cs}(3985)$. However the $Z_{cs}(3985)$ is more dependent on a mixture of different factors, which (besides axial meson exchange) include $η$ exchange and the nature of scalar meson exchange. Together they point towards the existence of two $Z_{cs}(3985)$-like resonances instead of one, while the observations about the role of scalar meson exchange in the $Z_{cs}(3985)$ might be relevant for the $P_{cs}(4459)$. Finally, the combination of axial meson exchange and flavor symmetry breaking effects indicates that the isovector $J^{PC} = 0^{++}$ $D^*\bar{D}^*$ and the strange $J^P = 2^{+}$ $D^*\bar{D}_s^*$ molecules are the most attractive configurations and thus the most likely molecular partners of the $Z_c(3900)$, $Z_c(4020)$ and $Z_{cs}(3985)$.

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。

摘要：

英文摘要：

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