The 39th International Symposium on Lattice Field Theory (Lattice 2022)

Pion pole contributions to HLbL at the physical point

11 Aug 2022, 10:40

20m

CP1-HSZ/0.001 (CP1-HSZ) - HS3 (CP1-HSZ)

Oral Presentation QCD in searches for physics beyond the Standard Model QCD in searches for physics beyond the Standard Model

Speaker

Gurtej Kanwar (University of Bern)

Description

Pseudoscalar pole diagrams provide the bulk of the contribution -- as well as a large fraction of the error budget -- of dispersive estimates of the hadronic light-by-light (HLbL) piece of the muon g-2. We report on a calculation of the pion transition form factor $F_{P\to \gamma \gamma }$ over a range of kinematics, including broad regions which are inaccessible from experimental data, which directly leads to an estimate of the pion pole contribution to the muon g-2. The results are evaluated using physical quark masses and are extrapolated to the continuum using twisted mass ensembles at several lattice spacings. Our result for the g-2 contribution is comparable with previous lattice and data-driven determinations, with combined uncertainties achieving sub-10% precision.

Presentation materials

PseudoscalarPoleContributionsToGm2_Final.pdf