Lattice QCD studies of the $\hat{I}”$ baryon resonance and the $K_0^{\ast }(700)$ and $a_0(980)$ meson resonances: the role of exotic operators in determining the finite-volume spectrum

Abstract

Studies of the $\hat{I}”$ baryon resonance and the $K_0^{\ast }(700)$ and $a_0(980)$ meson resonances using $N_f=2+1$ lattice QCD for pion masses near 200 MeV are presented. The $s$-wave scattering lengths for both the $I=1/2$ $N\ddot{I}€$ and $I=3/2$ $N\ddot{I}€$ channels and properties of the $\hat{I}”$ resonance are identified from the finite-volume energy levels of the lattice simulation. The importance of a three-quark $\hat{I}”$-operator in the $N\ddot{I}€$ system and tetraquark operators in the mesonic systems is investigated.

10 pages, 5 figures, 3 tables