An explanation of the $Δ_{5/2^{-}}(1930)$ as a $ρΔ$ bound state

Abstract

We use the $ρΔ$ interaction in the hidden gauge formalism to dynamically generate $N^{\ast}$ and $Δ^{\ast}$ resonances. We show, through a comparison of the results from this analysis and from a quark model study with data, that the $Δ_{5/2^{-}}(1930),$ $Δ_{3/2^{-}}(1940)$ and $Δ_{1/2^{-}}(1900)$ resonances can be assigned to $ρΔ$ bound states. More precisely the $Δ_{5/2^{-}}(1930)$ can be interpreted as a $ρΔ$ bound state whereas the $Δ_{3/2^{-}}(1940)$ and $Δ_{1/2^{-}}(1900)$ may contain an important $ρΔ$ component. This interpretation allows for a solution of a long-standing puzzle concerning the description of these resonances in constituent quark models. In addition we also obtain degenerate $J^{P}=1/2^{-},3/2^{-},5/2^{-}$ $N^{*}$ states but their assignment to experimental resonances is more uncertain.

19 pags, 8 figs