arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1807.00718hep-phhep-exhep-latnucl-th
收藏

作为强子分子的$Ω(2012)$

The $Ω(2012)$ as a hadronic molecule

M. Pavon Valderrama

摘要:

最近,Belle合作发现了一个窄的$S=-3$重子,$Ω(2012)$。我们探讨的可能性,PDMATHAMN是一个$Ξ(1530)\,\bar K$分子,其中的结合机制是耦合通道动力学与PDMATHAMP通道。分子$Ω(2012)$的特征信号将是其衰变为三体通道$Ξπ\bar{K}$,我们预计其部分衰变宽度为$2-3\,{\rm MeV}$。进入$Ξ\bar{K}$通道的部分衰减宽度应该在$1-11\,{\rm MeV}$的范围内,这是一个与实验相符的数字,我们从这个衰减中涉及的耦合是自然大小的假设中推导出来的。为了比较的目的,纯致密的$Ω(2012)$衰变到$Ξ\bar{K}$和$Ξπ\bar{K}$通道中的数量级分别与分子情况相同和小一个数量级。这种比较表明,当前的实验信息不足以区分致密和分子$Ω(2012)$,需要进一步的实验来确定其性质。分子$Ω(2012)$也意味着两体和三体分子伴侣的存在。二体伴侣由两个分别位于$1740$和$1950\,{\rm MeV}$的$Λ$超子组成,其中第一个超子可能对应于$Λ(1800)$,而第二个超子可能对应于$Λ(2000)$或$Λ(2050)$。三体伴侣包括$Ξ(1530) K\bar{K}$和$Ξ(1530) η\bar{K}$分子,质量分别为$M = 2385-2445\,{\rm MeV}$和$M = 2434-2503\,{\rm MeV}$。我们可能倾向于将前者与$Ξ(2370)$等同起来,将后者与PDG中列出的$Ω(2470)$等同起来。

英文摘要:

Recently the Belle collaboration has discovered a narrow $S=-3$ baryon, the $Ω(2012)$. We explore the possibility that the $Ω(2012)$ is a $Ξ(1530)\,\bar K$ molecule, where the binding mechanism is the coupled channel dynamics with the $Ω\,η$ channel. The characteristic signature of a molecular $Ω(2012)$ will be its decay into the three body channel $Ξπ\bar{K}$, for which we expect a partial decay width of $2-3\,{\rm MeV}$. The partial decay width into the $Ξ\bar{K}$ channel should lie in the range of $1-11\,{\rm MeV}$, a figure compatible with experiment and which we have deduced from the assumption that the coupling involved in this decay is of natural size. For comparison purposes the decay of a purely compact $Ω(2012)$ into the $Ξ\bar{K}$ and $Ξπ\bar{K}$ channels is of the same order of magnitude as and one order of magnitude smaller than in the molecular scenario, respectively. This comparison indicates that the current experimental information is insufficient to distinguish between a compact and a molecular $Ω(2012)$ and further experiments will be required to determine its nature. A molecular $Ω(2012)$ will also imply the existence of two- and three-body molecular partners. The two-body partners comprise two $Λ$ hyperons located at $1740$ and $1950\,{\rm MeV}$ respectively, the first of which might correspond to the $Λ(1800)$ while the second to the $Λ(2000)$ or the $Λ(2050)$. The three-body partners include a $Ξ(1530) K\bar{K}$ and a $Ξ(1530) η\bar{K}$ molecule, with masses of $M = 2385-2445\,{\rm MeV}$ and $M = 2434-2503\,{\rm MeV}$ respectively. We might be tempted to identify the first with the $Ξ(2370)$ and the latter with the $Ω(2470)$ listed in the PDG.

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。

↑