Examination of the nature of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>N</mml:mi><mml:mo>*</mml:mo></mml:msup></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi mathvariant="normal">Δ</mml:mi></mml:math> resonances via coupled-channels dynamics

Abstract

This work aims at determining the composition of certain ${N}^{*}$ and $\mathrm{\ensuremath{\Delta}}$ resonances, i.e., whether they are compact states formed directly by quarks and gluons, or hadronic molecules generated from the meson-baryon interaction. The information of the resonance poles is provided by a comprehensive coupled-channels approach, the J\"ulich-Bonn model. Thirteen states that are significant in this approach are studied. Two criteria for each state are adopted in this paper, the comparison thereof roughly indicates the model uncertainties. It is found that the conclusions for eight resonances are relatively certain: $N(1535){\frac{1}{2}}^{\ensuremath{-}}, N(1440){\frac{1}{2}}^{+}, N(1710){\frac{1}{2}}^{+}$, and $N(1520){\frac{3}{2}}^{\ensuremath{-}}$ tend to be composite, whereas $N(1650){\frac{1}{2}}^{\ensuremath{-}}, N(1900){\frac{3}{2}}^{+}, N(1680){\frac{5}{2}}^{+}$, and $\mathrm{\ensuremath{\Delta}}(1600){\frac{3}{2}}^{+}$ tend to be compact.

Topics & Concepts