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arXiv · 1107.0574

Coupling vector and pseudoscalar mesons to study baryon resonances

K. P. Khemchandani·A. Martínez Torres·H. Kaneko·H. Nagahiro·A. Hosaka
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Abstract

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.

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BibTeXRIS

K. P. Khemchandani, A. Martínez Torres, H. Kaneko, H. Nagahiro, A. Hosaka. 2011-07-06. Coupling vector and pseudoscalar mesons to study baryon resonances. https://doi.org/10.1103/physrevd.84.094018

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