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arXiv · 1710.11212

Strong-isospin-breaking correction to the muon anomalous magnetic moment from lattice QCD at the physical point

Bipasha Chakraborty·C. T. H. Davies·C. DeTar·A. X. El-Khadra·E. Gámiz·Steven Gottlieb·D. Hatton·J. Koponen·A. S. Kronfeld·J. Laiho·G. P. Lepage·Yuzhi Liu·P. B. Mackenzie·C. McNeile·E. T. Neil·J. N. Simone·R. Sugar·D. Toussaint·R. S. Van de Water·A. Vaquero
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Abstract

All lattice-QCD calculations of the hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment to-date have been performed with degenerate up- and down-quark masses. Here we calculate directly the strong-isospin-breaking correction to $a_\mu^{\rm HVP}$ for the first time with physical values of $m_u$ and $m_d$ and dynamical $u$, $d$, $s$, and $c$ quarks, thereby removing this important source of systematic uncertainty. We obtain a relative shift to be applied to lattice-QCD results obtained with degenerate light-quark masses of $\delta a_\mu^{{\rm HVP,} m_u \neq m_d}$= +1.5(7)%, in agreement with estimates from phenomenology and a recent lattice-QCD calculation with unphysically heavy pions.

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Bipasha Chakraborty, C. T. H. Davies, C. DeTar, A. X. El-Khadra, E. Gámiz, Steven Gottlieb, D. Hatton, J. Koponen, A. S. Kronfeld, J. Laiho, G. P. Lepage, Yuzhi Liu, P. B. Mackenzie, C. McNeile, E. T. Neil, J. N. Simone, R. Sugar, D. Toussaint, R. S. Van de Water, A. Vaquero. 2017-10-30. Strong-isospin-breaking correction to the muon anomalous magnetic moment from lattice QCD at the physical point. https://doi.org/10.1103/physrevlett.120.152001

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