Light-by-light forward scattering amplitudes in Lattice QCD

Antoine Gérardin, Jeremy Green, Oleksii Gryniuk, Georg von Hippel, Harvey B. Meyer, Vladimir Pascalutsa, Hartmut Wittig, M. Della Morte, P. Fritzsch, E. Gámiz Sánchez, C. Pena Ruano
2018 EPJ Web of Conferences  
We present our preliminary results on the calculation of hadronic light-by-light forward scattering amplitudes using vector four-point correlation functions computed on the lattice. Using a dispersive approach, forward scattering amplitudes can be described by γ^* γ^* → hadrons fusion cross sections and then compared with phenomenology. We show that only a few states are needed to reproduce our data. In particular, the sum rules considered in this study imply relations between meson-γγ
more » ... and provide valuable information about individual form factors which are often used to estimate the meson-pole contributions to the hadronic light-by-light contribution to the (g-2) of the muon.
doi:10.1051/epjconf/201817506030 fatcat:5jxcs7njgfaozf5jmijo46vy6y