Tetraquark bound states in the heavy-light heavy-light system

A calculation of the interaction potential of two heavy-light mesons in lattice QCD is used to study the existence of tetraquark bound states. The interaction potential of the tetraquark system is calculated on the lattice with $2+1$ flavors of dynamical fermions with lattice interpolating fields constructed using color wave propagators. These propagators provide a method for constructing all-to-all spatially smeared interpolating fields, a technique which allows for a better overlap with the ground state wave function as well as reduced statistical noise. Potentials are extracted for 24 distinct channels, and are fit with a phenomenological nonrelativistic quark model potential, from which a determination of the existence of bound states is made via numerical solution of the two body radial Schr\"odinger equation.