Two nucleon systems at mπ ∼ 450 MeV from lattice QCD

Nucleon-nucleon systems are studied with lattice quantum chromodynamics at a pion mass of m(pi) similar to 450 MeV in three spatial volumes using n(f) = 2 + 1 flavors of light quarks. At the quark masses employed in this work, the deuteron binding energy is calculated to be B-d = 14.4(-2.6)(+3.2) MeV, while the dineutron is bound by B-nn = 12.5(-5.0)(+3.0) MeV. Over the range of energies that are studied, the S-wave scattering phase shifts calculated in the S-1(0) and S-3(1)-D-3(1) channels are found to be similar to those in nature, and indicate repulsive short-range components of the interactions, consistent with phenomenological nucleon-nucleon interactions. In both channels, the phase shifts are determined at three energies that lie within the radius of convergence of the expansion, allowing for constraints to be placed on the inverse scattering lengths and effective ranges. The extracted phase shifts allow for matching to nuclear effective field theories, from which low-energy counterterms are extracted and issues of convergence are investigated. As part of the analysis, a detailed investigation of the single hadron sector is performed, enabling a precise determination of the violation of the Gell-Mann-Okubo mass relation.