English

Higher-order hadronic vacuum polarization contribution to the muon $g-2$ from lattice QCD

High Energy Physics - Lattice 2026-04-13 v2 High Energy Physics - Phenomenology

Abstract

We present the first lattice QCD calculation of the next-to-leading order hadronic vacuum polarization contribution to the muon anomalous magnetic moment with sub-percent precision. We employ the time-momentum representation for the space-like kernel, which is combined with the spatially summed vector correlator computed on CLS ensembles with Nf=2+1N_{\mathrm{f}}=2+1 flavors of O(a)\mathrm{O}(a)-improved Wilson fermions, covering six lattice spacings between 0.0390.039 and 0.0970.097\,fm and a range of pion masses including the physical value. After accounting for finite-size corrections and isospin-breaking effects, we obtain as our final, continuum-extrapolated result aμhvp,nlo=101.57(26)stat(54)syst×1011a_\mu^{\mathrm{hvp,\,nlo}}=-101.57(26)_{\mathrm{stat}}(54)_{\mathrm{syst}}\times10^{-11}. It lies below the estimate provided by the 2025 White Paper of the Muon (g2)(g-2) Theory Initiative by 1.4σ1.4\sigma but is two times more precise. It also exhibits a strong tension of 4.6σ4.6\sigma with data-driven evaluations based on hadronic cross section measurements excluding the recent result by CMD-3.

Keywords

Cite

@article{arxiv.2603.06806,
  title  = {Higher-order hadronic vacuum polarization contribution to the muon $g-2$ from lattice QCD},
  author = {Arnau Beltran and Alessandro Conigli and Simon Kuberski and Harvey B. Meyer and Konstantin Ottnad and Hartmut Wittig},
  journal= {arXiv preprint arXiv:2603.06806},
  year   = {2026}
}

Comments

44 pages, 15 figures, 16 tables. v2: scale-setting input updated. All results adjusted accordingly; conclusions unchanged