Lattice QCD calculation of nuclear parity violation

We present a lattice QCD calculation of the leading-order momentum-independent parity-violating coupling between pions and nucleons, h_πNN¹. The calculation performs measurements on dynamical anisotropic clover gauge configurations, with a spatial extent of L~2.5 fm, a spatial lattice spacing of aₛ~0.123 fm, and a pion mass of m_π~389 MeV. While this calculation does not include nonperturbative renormalization of the bare parity-violating operators, a chiral extrapolation to the physical pion mass, or contributions from disconnected (quark-loop) diagrams, these are expected to result in systematic errors within the quoted statistical error. We find a contribution from the ``connected'' diagrams of h_πNN1,con=(1.099±0.505_-0.064+0.058)×10^-7, consistent with current experimental bounds and previous model-dependent theoretical predictions.