ORCID
- McNeile, Craig: 0000-0003-0305-2028
Abstract
We calculate the contribution to the muon anomalous magnetic moment hadronic vacuum polarization from the connected diagrams of up and down quarks, omitting electromagnetism. We employ QCD gauge-field configurations with dynamical $u$, $d$, $s$, and $c$ quarks and the physical pion mass, and analyze five ensembles with lattice spacings ranging from a~0.06-0.15 fm. The up- and down-quark masses in our simulations have equal masses $m_l$. We obtain, in this world where all pions have the mass of the $\pi^0$, $10^{10} a_\mu^{ll}({\rm conn.}) = 630.1(8.3)$, in agreement with independent lattice-QCD calculations. We then combine this value with published lattice-QCD results for the connected contributions from strange, charm, and bottom quarks, and an estimate of the uncertainty due to the fact that our calculation does not include strong-isospin breaking, electromagnetism, or contributions from quark-disconnected diagrams. We obtain for the total order $(\alpha^2)$ hadronic-vacuum polarization to the muon's anomalous magnetic moment $10^{10} a_\mu^{\rm HVP,LO} = 691(8)_{u,d}(1)_{s,c,b} (13)_{\rm other}$, where the errors are from the light-quark connected contribution, heavy-flavor connected contributions, and omitted effects listed above, respectively. Our result agrees with both $ab-initio$ lattice-QCD calculations and phenomenological determinations from experimental $e^+e^-$-scattering data. It is 1.7$\sigma$ below the "no new physics" value of the hadronic-vacuum-polarization contribution inferred from combining the BNL E821 measurement of $a_\mu$ with theoretical calculations of the other contributions.
DOI
10.1103/PhysRevD.101.034512
Publication Date
2020-02-18
Publication Title
Physical Review D: Particles, Fields, Gravitation and Cosmology
ISSN
1550-2368
Embargo Period
2020-02-22
Organisational Unit
School of Engineering, Computing and Mathematics
Keywords
hep-lat, hep-ph
Recommended Citation
Davies, C., DeTar, C., El-Khadra, A., Gamiz, E., Gottlieb, S., Hatton, D., Kronfeld, A., Laiho, J., Lepage, G., Liu, Y., Mackenzie, P., McNeile, C., Neil, E., Primer, T., Simone, J., Toussaint, D., Water, R., & Vaquero, A. (2020) 'Hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment from four-flavor lattice QCD', Physical Review D: Particles, Fields, Gravitation and Cosmology, . Available at: https://doi.org/10.1103/PhysRevD.101.034512
