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arXiv 1107.0574nucl-th
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耦合矢量和赝标介子研究重子共振态

Coupling vector and pseudoscalar mesons to study baryon resonances

K. P. Khemchandani, A. Martínez Torres, H. Kaneko, H. Nagahiro, A. Hosaka

摘要:

本文在手征对称性和隐局域对称性的框架下研究了全奇异度为-1的介子-重子系统。这些系统包括八重态重子、赝标介子和矢量介子。赝标介子-重子(PB)动力学已被发现是某些奇异1共振态(如$Λ(1405)$、$Λ(1670)$等)存在的决定因素。为此,我们得到的$PB \rightarrow PB$和$VB \rightarrow VB$振幅的t-通道图和$PB \leftrightarrow VB$振幅计算使用Kroll-Ruddermann项,考虑到矢量介子的优势现象,光子被替换为矢量介子。在该形式体系内进行的计算揭示了VB通道与$Λ(1405)$和$Λ(1670)$的非常强的耦合。在同位旋1的情况下,我们发现一个双极结构的$Σ(1480)$,像同位旋0共振,也被发现强烈耦合到VB通道的证据。这些低洼共振的VB通道的强耦合可以产生它们的某些反应具有重要的意义。

英文摘要:

A study of meson-baryon systems with total strangeness -1 is made within a framework based on the chiral and hidden local symmetries. These systems consist of octet baryons, pseudoscalar and vector mesons. The pseudoscalar meson-baryon (PB) dynamics has been earlier found determinant for the existence of some strangeness -1 resonances, for example, $Λ(1405)$, $Λ(1670)$, etc. The motivation of the present work is to study the effect of coupling the closed vector meson-baryon (VB) channels to these resonances. To do this, we obtain the $PB \rightarrow PB$ and $VB \rightarrow VB$ amplitudes from the t-channel diagrams and the $PB \leftrightarrow VB$ amplitudes are calculated using the Kroll-Ruddermann term where, considering the vector meson dominance phenomena, the photon is replaced by a vector meson. The calculations done within this formalism reveal a very strong coupling of the VB channels to the $Λ(1405)$ and $Λ(1670)$. In the isospin 1 case, we find an evidence for a double pole structure of the $Σ(1480)$ which, like the isospin 0 resonances, is also found to couple strongly to the VB channels. The strong coupling of these low-lying resonances to the VB channels can have important implications on certain reactions producing them.

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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