# The 34th International Symposium on Lattice Field Theory (Lattice 2016)

Jul 24 – 30, 2016
Highfield Campus, University of Southampton
Europe/London timezone

## Position-space approach to hadronic light-by-light scattering in the muon $g-2$ on the lattice

Jul 26, 2016, 3:40 PM
20m
Building B2a Room 2077 (Highfield Campus, University of Southampton)

### Speaker

Mr Nils Asmussen (Institut für Kernphysik, Johannes Gutenberg-Universität Mainz)

### Description

The anomalous magnetic moment of the muon currently shows a more than $3\sigma$ discrepancy between the experimental value and recent Standard Model predictions. The theoretical uncertainty is dominated by the hadronic vacuum polarization and the hadronic light-by-light (HLbL) scattering contributions, where the latter has so far only been fully evaluated using different models. To pave the way for a lattice calculation of HLbL, we present an expression for the HLbL contribution to $g-2$ that involves a multidimensional integral over a position-space QED kernel function in the continuum and a lattice QCD four-point correlator. We describe our semi-analytic calculation of the kernel and test the approach by evaluating the $\pi^0$-pole contribution in the continuum.

### Primary authors

Dr Andreas Nyffeler (Institut für Kernphysik, Johannes Gutenberg-Universität Mainz) Prof. Harvey B. Meyer (Institut für Kernphysik, Johannes Gutenberg-Universität Mainz) Dr Jeremy Green (Institut für Kernphysik, Johannes Gutenberg-Universität Mainz) Mr Nils Asmussen (Institut für Kernphysik, Johannes Gutenberg-Universität Mainz)

 Slides