arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2109.03504hep-ph
收藏

从单玻色子交换模型研究$Σ_c^{(*)}\bar{D}^{(*)}$ - $Λ_c(2595)\bar{D}$系统的耦合通道效应和$P_c$五夸克态的分子性质

Coupled-channel effects of the $Σ_c^{(*)}\bar{D}^{(*)}$-$Λ_c(2595)\bar{D}$ system and molecular nature of the $P_c$ pentaquark states from one-boson exchange model

Nijiati Yalikun, Yong-Hui Lin, Feng-Kun Guo, Yuki Kamiya, Bing-Song Zou

备注：
34 pages, 6 figures, 8 tables
发表信息：
Phys. Rev. D 104, 094039 (2021)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

重新研究了LHCb五夸克态$P_c(4440)$和$P_c(4457)$的$Σ_c\bar{D}^*$ - $Λ_{c}(2595)\bar{D}$耦合通道动力学和各种单玻色子交换（OBE）力的影响。在$Σ_c\bar{D}^*$ - $Λ_{c}(2595)\bar{D}$耦合通道动力学中，考虑了π介子和$ρ$ -介子交换.结果表明，当OBE参数受其它实验源的限制时，$Λ_{c}(2595)\bar{D}$通道在描述$P_c(4440)$和$P_c(4457)$态中的作用不显著.具有一π交换（OPE）的短距离$δ(\vec{r})$项的朴素OBE模型一直不能同时再现$P_c(4440)$和$P_c(4457)$态。全$δ(\vec{r})$项的OPE势导致$J^P=1/2^-$和全同位旋$I=1/2$的$3/2^-$ $Σ_c\bar{D}^*$束缚态的质量分裂过大。仅去掉OPE $δ(\vec{r})$项的OBE模型可能更好地拟合分裂，但有些低估了分裂。由于$δ(\vec r)$势是来自短程物理的，它也包含了比明确考虑的重的介子交换的贡献，我们改变$δ(\vec r)$势的强度，发现$P_c(4312)$，$P_c(4440)$和$P_c(4457)$的质量可以同时再现，而OBE模型中的$δ(\vec r)$项减少了约80%.虽然两种不同的自旋分配可以产生它们的质量，但是在优选的描述中，$P_c(4440)$和$P_c(4457)$的自旋宇称分别是$3/2^-$和$1/2^-$。

英文摘要：

The effects of the $Σ_c\bar{D}^*$-$Λ_{c}(2595)\bar{D}$ coupled-channel dynamics and various one-boson-exchange (OBE) forces for the LHCb pentaquark states, $P_c(4440)$ and $P_c(4457)$, are reinvestigated. Both the pion and $ρ$-meson exchanges are considered for the $Σ_c\bar{D}^*$-$Λ_{c}(2595)\bar{D}$ coupled-channel dynamics. It is found that the role of the $Λ_{c}(2595)\bar{D}$ channel in the descriptions of the $P_c(4440)$ and $P_c(4457)$ states is not significant with the OBE parameters constrained by other experimental sources. The naive OBE models with the short-distance $δ(\vec{r})$ term of the one-pion exchange (OPE) keep failing to reproduce the $P_c(4440)$ and $P_c(4457)$ states simultaneously. The OPE potential with the full $δ(\vec{r})$ term results in a too large mass splitting for the $J^P=1/2^-$ and $3/2^-$ $Σ_c\bar{D}^*$ bound states with total isospin $I=1/2$. The OBE model with only the OPE $δ(\vec{r})$ term dropped may fit the splitting much better but somewhat underestimates the splitting. Since the $δ(\vec r)$ potential is from short-distance physics, which also contains contributions from the exchange of mesons heavier than those considered explicitly, we vary the strength of the $δ(\vec r)$ potential and find that the masses of the $P_c(4312)$, $P_c(4440)$, and $P_c(4457)$ can be reproduced simultaneously with the $δ(\vec r)$ term in the OBE model reduced by about 80\%. While two different spin assignments are possible to produce their masses, in the preferred description, the spin parities of the $P_c(4440)$ and $P_c(4457)$ are $3/2^-$ and $1/2^-$, respectively.

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。

↑