English

The hadronic vacuum polarization contribution to $(g_\mu-2)$: Lattice QCD+QED calculations

High Energy Physics - Lattice 2019-10-10 v2 High Energy Physics - Experiment High Energy Physics - Phenomenology

Abstract

The anomalous magnetic moment of the muon aμa_\mu is one of the most accurate quantities in Particle Physics. The long-standing discrepancy of about 3.73.7 standard deviations between the experimental value and the prediction of the Standard Model could represent an intriguing indication of New Physics. The experiments at Fermilab (E989) and at J-PARC (E34) aim at reducing significantly the experimental uncertainty, thus making the theoretical one due to hadronic corrections the main limitation of this stringent test of the Standard Model. In this contribution we present the results of a first-principles lattice calculation of the hadronic vacuum polarization (HVP) contribution to aμa_\mu, including electromagnetic and SU(2)SU(2)-breaking corrections. Our determination, aμHVP=682.0 (18.7)1010a_\mu^{\rm HVP} = 682.0 ~ (18.7) \cdot 10^{-10}, turns out to be in agreement with recent theoretical determinations based on the dispersive analyses of the experimental cross section data for the annihilation process e+ehadronse^+e^- \to hadrons. Furthermore, we provide for the first time a lattice estimate for the missing part of aμHVPa_\mu^{\rm HVP} not covered in the MUonE experiment, [aμHVP]>=91.6 (2.0)1010\left[a_\mu^{\rm HVP}\right]_> = 91.6 ~ (2.0) \cdot 10^{-10}.

Keywords

Cite

@article{arxiv.1910.00611,
  title  = {The hadronic vacuum polarization contribution to $(g_\mu-2)$: Lattice QCD+QED calculations},
  author = {Davide Giusti and Silvano Simula},
  journal= {arXiv preprint arXiv:1910.00611},
  year   = {2019}
}

Comments

Invited plenary talk at IFAE 2019, Napoli (Italy), 08-10 April 2019. v2: extended version, 5 pages, 1 figure