The hadronic-vacuum-polarization contribution to the muon anomalous magnetic moment in isospin-symmetric lattice QCD with twisted-mass fermions
Abstract
We present a lattice-QCD calculation of the leading-order hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon in isospin-symmetric QCD. We employ the gauge configurations generated by the Extended Twisted Mass Collaboration (ETMC) with Nf = 2 + 1 + 1 flavors of Wilson-clover twisted-mass quarks at four lattice spacings and at values of the quark-mass parameters matching the definition of isospin-symmetric QCD given in the FLAG review 2024 and in the 2025 edition of the Muon g−2 Theory Initiative White Paper (WP25). After retuning the simulation parameters to precisely match these two definitions of isospin-symmetric QCD, and after carrying out an extrapolation to the continuum limit based on the data at lattice spacings a ≃ 0.049, 0.057, 0.068 and $0.079$~fm, and spatial lattice sizes up to L ≃ 7.7~fm, we obtain aμHVP, FLAG(iso) = (720.0 ± 6.9) × 10−10 and aμHVP, WP25(iso) = (714.8 ± 7.4) × 10−10. Our results, which have a relative uncertainty of about 1 %, agree well with the corresponding determinations by other lattice groups. After adding to our determination of aμHVP, WP25(iso) the leading isospin-breaking corrections provided in the WP25, namely aμHVP, WP25(IB) = 0.1(3.4)× 10−10, we obtain for the full HVP the value aμHVP= (714.9 ± 8.1)× 10−10. This result translates into a Standard Model prediction for the muon anomalous magnetic moment that is fully consistent with the latest result by the Fermilab Muon g−2 experiment and strengthens the tension between lattice QCD and data-driven (pre-CMD3) dispersive determinations.
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BibTeX
@misc{alexandrou2026hadronicvacuumpolarization,
title = {{The hadronic-vacuum-polarization contribution to the muon anomalous magnetic moment in isospin-symmetric lattice QCD with twisted-mass fermions}},
author = {C. Alexandrou and S. Bacchio and A. De Santis and A. Evangelista and J. Finkenrath and R. Frezzotti and G. Gagliardi and M. Garofalo and N. Kalntis and B. Kostrzewa and V. Lubicz and L. Maio and F. Margari and F. Pittler and S. Romiti and F. Sanfilippo and C. Schneider and S. Simula and N. Tantalo and C. Urbach and U. Wenger},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.22224},
eprint = {2610.22224},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.22224},
}
RIS
TY - UNPB
TI - The hadronic-vacuum-polarization contribution to the muon anomalous magnetic moment in isospin-symmetric lattice QCD with twisted-mass fermions
AU - C. Alexandrou
AU - S. Bacchio
AU - A. De Santis
AU - A. Evangelista
AU - J. Finkenrath
AU - R. Frezzotti
AU - G. Gagliardi
AU - M. Garofalo
AU - N. Kalntis
AU - B. Kostrzewa
AU - V. Lubicz
AU - L. Maio
AU - F. Margari
AU - F. Pittler
AU - S. Romiti
AU - F. Sanfilippo
AU - C. Schneider
AU - S. Simula
AU - N. Tantalo
AU - C. Urbach
AU - U. Wenger
PY - 2026
DA - 2026/10/15
PB - arXiv
DO - 10.48550/arxiv.2610.22224
UR - https://arxiv.org/abs/2610.22224
AB - We present a lattice-QCD calculation of the leading-order hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon in isospin-symmetric QCD. We employ the gauge configurations generated by the Extended Twisted Mass Collaboration (ETMC) with N_f = 2 + 1 + 1 flavors of Wilson-clover twisted-mass quarks at four lattice spacings and at values of the quark-mass parameters matching the definition of isospin-symmetric QCD given in the FLAG review 2024 and in the 2025 edition of the Muon g−2 Theory Initiative White Paper (WP25). After retuning the simulation parameters to precisely match these two definitions of isospin-symmetric QCD, and after carrying out an extrapolation to the continuum limit based on the data at lattice spacings a ≃ 0.049, 0.057, 0.068 and $0.079$~fm, and spatial lattice sizes up to L ≃ 7.7~fm, we obtain a_μ^HVP, FLAG(iso) = (720.0 ± 6.9) × 10^−10 and a_μ^HVP, WP25(iso) = (714.8 ± 7.4) × 10^−10. Our results, which have a relative uncertainty of about 1 %, agree well with the corresponding determinations by other lattice groups. After adding to our determination of a_μ^HVP, WP25(iso) the leading isospin-breaking corrections provided in the WP25, namely a_μ^HVP, WP25(IB) = 0.1(3.4)× 10^−10, we obtain for the full HVP the value a_μ^HVP= (714.9 ± 8.1)× 10^−10. This result translates into a Standard Model prediction for the muon anomalous magnetic moment that is fully consistent with the latest result by the Fermilab Muon g−2 experiment and strengthens the tension between lattice QCD and data-driven (pre-CMD3) dispersive determinations.
ER -