Speaker
Description
We report on our completed study of the role of tetraquark interpolating operators in the isodoublet strange $\kappa$ and isovector nonstrange $a_0(980)$ scalar channels using $N_f = 2+1$ lattice QCD at $m_\pi \simeq 230\:\mathrm{MeV}$. We compare finite-volume spectra extracted using Hermitian correlation matrices constructed with and without tetraquark operators and find substantial differences in the resolved energy levels. The spectra are then used in the $2\to2$ finite-volume quantization condition to constrain the scattering $K$-matrix, allowing for a qualitative comparison of the resulting descriptions. Time permitting, we also present a progress report on our study of higher partial waves in the di-nucleon system at a heavy, flavor-symmetric point, $m_\pi = m_K \simeq 714\:\mathrm{MeV}$.