English

Negative parity $\Lambda$ and $\Sigma$ resonances coupled to pseudoscalar and vector mesons

Nuclear Theory 2015-06-04 v1

Abstract

An exploration of the dynamically generated Λ\Lambda and Σ\Sigma resonances has been made in the vector meson-baryon (VB) systems coupled to pseudoscalar meson-baryon (PB) channels. The VB interactions are obtained from the Lagrangians written within the hidden local symmetry which, in addition to Yukawa-type vector-baryon-baryon (VBB) vertices, naturally gives rise to a contact interaction. Using the VBB vertices, we calculate the tt-, ss- and uu-channel diagrams considering the octet baryon exchange in the latter two cases. For the PB channels we rely on the the Weingberg-Tomozawa interactions and calculate the PB \leftrightarrow VB transition amplitudes extending the Kroll-Ruderman theorem by replacing the photon by the vector mesons. In addition to the low-lying Λ(1405)\Lambda(1405), Λ(1670)\Lambda(1670) found in previous works, we find resonances which coincide well with: Λ(2000)\Lambda(2000), Σ(1750)S11\Sigma(1750) S_{11}, Σ(1940)D13\Sigma(1940) D_{13}, Σ(2000)S11\Sigma(2000) S_{11} and predict three Λ\Lambda^*'s with Jπ=3/2J^\pi = 3/2^- and masses: 1754i21754 - i2 MeV, 1862i331862 - i33 MeV, 2139i142139 - i14 MeV together with a broad 1/21/2^- Σ\Sigma^* with mass \sim 1430 MeV. We find that most of these next-to-low-lying states couple weakly with the pseudoscalar mesons, which implies that it is important to study the reactions with VB final states in order to obtain a reliable information on the properties of such resonances.

Keywords

Cite

@article{arxiv.1203.6711,
  title  = {Negative parity $\Lambda$ and $\Sigma$ resonances coupled to pseudoscalar and vector mesons},
  author = {K. P. Khemchandani and A. Martínez Torres and H. Nagahiro and A. Hosaka},
  journal= {arXiv preprint arXiv:1203.6711},
  year   = {2015}
}
R2 v1 2026-06-21T20:42:13.863Z