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arXiv 1702.04604nucl-thhep-phnucl-ex
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$πN\to πN$反应到$N(1440)$共振区的夸克模型研究

Quark model study of the $πN\to πN$ reactions up to the $N(1440)$ resonance region

Kai-Lei Wang, Li-Ye Xiao, Xian-Hui Zhong

备注：
15 pages, 11 figures, submitted to PRC. arXiv admin note: text overlap with arXiv:1602.04455
发表信息：
Phys. Rev. C 95, 055204 (2017)
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摘要：

本文用手征夸克模型对反应$π^+p\to π^+p$、$π^-p\to π^-p$和$π^-p\to π^0n$进行了联合分析。从$Δ(1232)$共振区到$N(1440)$共振区的观测结果得到了合理的描述。除$Δ(1232)P_{33}$外，在$π^-p\to π^-p$和$π^-p\toπ^0n$反应的极化中发现了$N(1440)P_{11}$的确认作用。发现$N(1440)Nπ$和$Δ(1232)Nπ$耦合分别比简单夸克模型的预期值大约$1.7$和$4.8$倍，这可能表明了$N(1440)P_{11}$的特殊性质以及简单夸克模型在描述$N(1440)P_{11}$和$Δ(1232)P_{33}$时的不足. $t$ -和$u$ -通道背景对$π^+ p\rightarrowπ^+ p$反应有显著的贡献，而在$π^-p\rightarrow π^- p,π^0 n$反应中，$s$ -通道核子和$t$ -和$u$ -通道背景起关键作用.

英文摘要：

A combined analysis of the reactions $π^+p\to π^+p$, $π^-p\to π^-p$ and $π^-p\to π^0n$ is carried out with a chiral quark model. The observations are reasonably described from the $Δ(1232)$ resonance region up to the $N(1440)$ resonance region. Besides the $Δ(1232)P_{33}$, a confirmed role of $N(1440)P_{11}$ is found in the polarizations of the $π^-p\to π^-p$ and $π^-p\toπ^0n$ reactions. It is found that the $N(1440)Nπ$ and $Δ(1232)Nπ$ couplings are about $1.7$ and $4.8$ times larger than the expectations from the simple quark model, respectively, which may suggest the unusual property of $N(1440)P_{11}$ and deficiency of the simple quark model in the description of $N(1440)P_{11}$ and $Δ(1232)P_{33}$. The $t$- and $u$-channel backgrounds have notable contributions to the $π^+ p\rightarrowπ^+ p$ reaction, while in the $π^-p\rightarrow π^- p,π^0 n$ reactions, the $s$-channel nucleon and $t$- and $u$-channel backgrounds play crucial roles.

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。

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