Centre de Physique Théorique


Vendredi 23 novembre 2018

14h00 – 15h00, Amphi 5 du CPT

Hadronic light-by-light scattering in the muon g-2 from lattice QCD

Antoine Gérardin (DESY Zeuthen)

The anomalous magnetic moment of the muon is one of the most promising observables to identify hints for physics beyond the Standard Model of particle physics. This quantity exhibits a persistent discrepancy of 3.5 standard deviations between the direct measurement by the Brookhaven E821 Collaboration and its theoretical prediction based on the Standard Model. The theory error is entirely dominated by effects of the strong interaction and in particular by the hadronic light-by-light scattering contribution.
I will present a lattice calculation of this contribution based on a convolution integral between a QED kernel, computed semi-analytically in position space and in infinite volume, with the four point correlation function of the electromagnetic current computed on the lattice. I will also explain how the pseudoscalar pole contribution, computed on the same lattices, can help to reduce the overall precision.