Hadron-hadron scattering phase shifts from Lattice QCD
Lattice QCD simulation is the only systematically improvable technique for obtaining first-principles information from the strong nuclear force (QCD). Because such simulations are necessarily performed in Euclidean time (rather than real Minkowski time), obtaining real-time scattering information is difficult and must be inferred from finite-volume energy spectra. Fortunately, recent algorithmic advances have enabled these spectra to calculated with unprecedented precision, enabling realistic scattering phase shift calculations in large volumes and light pion masses for the first time. I will report on such a calculation of the $I=1$ pion-pion scattering phase shift and discuss prospects for other systems.