We present the first calculation of coupled-channel meson-meson scattering in the isospin =1, G-parity negative sector, with channels πη, K$\bar K$ and πη′, in a first-principles approach to QCD. From the discrete spectrum ...

We present a determination of the P-wave ππ→πγ$^{⋆}$ transition amplitude from lattice quantum chromodynamics. Matrix elements of the vector current in a finite volume are extracted from three-point correlation functions, ...