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arXiv · 1710.09359

Light-by-light forward scattering amplitudes in Lattice QCD

Antoine Gerardin·Jeremy Green·Oleksii Gryniuk·Georg von Hippel·Harvey B. Meyer·Vladimir Pascalutsa·Hartmut Wittig
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Abstract

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 $\gamma^* \gamma^* \to$ 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$-\gamma\gamma$ couplings 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.

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Antoine Gerardin, Jeremy Green, Oleksii Gryniuk, Georg von Hippel, Harvey B. Meyer, Vladimir Pascalutsa, Hartmut Wittig. 2017-10-25. Light-by-light forward scattering amplitudes in Lattice QCD. https://doi.org/10.1051/epjconf/201817506030

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