1. Hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment from four-flavor lattice QCD.
- Author
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Davies, C. T. H., DeTar, C., El-Khadra, A. X., Gámiz, E., Gottlieb, Steven, Hatton, D., Kronfeld, A. S., Laiho, J., Lepage, G. P., Yuzhi Liu, Mackenzie, P. B., McNeile, C., Neil, E. T., Primer, T., Simone, J. N., Toussaint, D., Van de Water, R. S., and Vaquero, A.
- Subjects
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MUONS , *MAGNETIC moments , *VACUUM polarization , *ELECTROMAGNETISM , *AB-initio calculations , *QUARKS , *COSMIC ray showers , *PENTAQUARK - 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 to 0.15 fm. The up- and down-quark masses in our simulations have equal masses ml. We obtain, in this world where all pions have the mass of the π0, 1010allμ(conn.)=637.8(8.8), 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. Our final result for the total O(α²) hadronic-vacuum polarization to the muon's anomalous magnetic moment is 1010aHVP,LOμ=699(15)u,d(1)s,c,b, where the errors are from the light-quark and heavy-quark contributions, respectively. Our result agrees with both ab-initio lattice-QCD calculations and phenomenological determinations from experimental e+e--scattering data. It is 1.3σ below the "no new physics" value of the hadronic-vacuum-polarization contribution inferred from combining the BNL E821 measurement of aμ with theoretical calculations of the other contributions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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