English

Coupled channels approach to $\eta N$ and $\eta' N$ interactions

Nuclear Theory 2020-01-24 v2 High Energy Physics - Phenomenology

Abstract

We present a coupled channels separable potential approach to ηN\eta N and ηN\eta'N interactions using a chiral-symmetric interaction kernel. The s-wave πN\pi N amplitudes and πp\pi^{-}p induced total cross sections are reproduced satisfactorily in a broad interval of energies despite limiting the channel space to two-body interactions of pseudoscalar mesons with the baryon ground-state octet. It is demonstrated that an explicit inclusion of the η0\eta_0 meson singlet field leads to a more attractive ηN\eta N interaction, with the real part of the scattering length exceeding 1 fm. The ηN\eta'N diagonal coupling appears sufficient to generate an ηN\eta'N bound state but the inter-channel dynamics moves the respective pole far from physical region making the ηN\eta'N interaction repulsive at energies around the channel threshold. The N(1535)N^{*}(1535) and N(1650)N^{*}(1650) resonances are generated dynamically and the origin and properties of the SS-matrix poles assigned to them are studied in detail. We also hint at a chance that the N(1895)N^{*}(1895) state might also be formed provided a suitably varied model setting is found.

Keywords

Cite

@article{arxiv.1903.10350,
  title  = {Coupled channels approach to $\eta N$ and $\eta' N$ interactions},
  author = {Ales Cieply and Peter C. Bruns},
  journal= {arXiv preprint arXiv:1903.10350},
  year   = {2020}
}

Comments

51 pages, 16 figures, version accepted for publication in Nucl. Phys. A (fitting procedure altered with respect to previous version resulting in new fits, that provide results very similar to the previous ones, and conclusions remain the same)