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T: Fachverband Teilchenphysik

T 69: Strong Interaction / QCD

T 69.8: Vortrag

Donnerstag, 3. April 2025, 18:00–18:15, VG 0.110

Lattice determination of the higher-order hadronic vacuum polarization contributions to the muon g-2. — •Arnau Beltran Martínez¹ and Hartmut Wittig^1,2 — ¹PRISMA+ Cluster of Excellence and Institut für Kernphysik, Johannes Gutenberg-Universität, Mainz, Germany — ²Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, Mainz, Germany

We present initial results from a lattice QCD computation for the next-to-leading order (NLO) contribution to the hadronic vacuum polarization (HVP) of the muon g−2. Our approach is based on the time-momentum representation (TMR) involving three kernels needed to compute the different NLO HVP diagrams, following the framework developed by Balzani, Laporta and Passera.

For the NLO corrections involving extra photon or lepton lines, we present analytical series expansions for small values of the Euclidean time and numerical series expansions for the large time values. The NLO diagram with two QCD insertions is solved analytically and expanded across different regions of the two-dimensional Euclidean time plane.

These results are then combined with lattice QCD calculations of the vector correlator performed on more than 30 gauge ensembles using O(a)-improved Wilson quarks. To control the continuum limit, we implement two improvement schemes, each combining two discretizations. After correcting for finite-volume effects, we perform a combined chiral and continuum extrapolation to the physical point, yielding a final estimate for a_µ^hvp[NLO].

Keywords: Lattice QCD; Anomalous magnetic moment; NLO HVP; Muon g-2