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The anomalous magnetic moment of the muon, $g_\mu-2$, is one of the most promising observables to identify hints for physics beyond the Standard Model. QCD contributions are currently responsible for the largest fraction of the overall…

We reevaluate the hadronic part of the electromagnetic vacuum expectation value using the standard dispersion integral approach that utilizes the hadronic cross section measured in $\ee$ experiments as input. Previous analyses are based…

High Energy Physics - Phenomenology · Physics 2015-06-25 Morris L. Swartz

We report our (HPQCD) progress on the calculation of the Hadronic Vacuum Polarisation contribution to the anomalous magnetic moment of muon. In this article we discuss the calculations for the light (up/down) quark connected contribution…

High Energy Physics - Lattice · Physics 2015-11-19 Bipasha Chakraborty , Christine Davies , Pedro Gonçalves de Oliveira , Jonna Koponen , G. Peter Lepage

We reevaluate the hadronic contribution to the running of the QED fine structure constant alpha(s) at s = M_Z^2. We use data from e+e- annihilation and tau decays at low energy and at the qq-bar thresholds, where resonances occur. Using…

High Energy Physics - Phenomenology · Physics 2016-02-17 M. Davier , A. Hoecker

The comparison of the theoretical and experimental determinations of the anomalous magnetic moment of the muon $(g-2)_\mu$ constitutes one of the strongest tests of the Standard Model at low energies. In this article, we compute the leading…

We determine the contribution to the anomalous magnetic moment of the muon from the $\alpha^2_{\mathrm{QED}}$ hadronic vacuum polarization diagram using full lattice QCD and including $u/d$ quarks with physical masses for the first time. We…

High Energy Physics - Lattice · Physics 2017-08-30 Bipasha Chakraborty , C. T. H. Davies , P. G. de Oliviera , J. Koponen , G. P. Lepage , R. van de Water

We present a lattice-QCD calculation of the light-quark connected contribution to window observables associated with the leading-order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon,…

We report the first result for the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment with all errors systematically controlled. Several ensembles using 2+1 flavors of physical mass M\"obius domain-wall…

High Energy Physics - Lattice · Physics 2020-04-08 Thomas Blum , Norman Christ , Masashi Hayakawa , Taku Izubuchi , Luchang Jin , Chulwoo Jung , Christoph Lehner

We describe a new technique to determine the contribution to the anomalous magnetic moment of the muon coming from the hadronic vacuum polarization using lattice QCD. Our method reconstructs the Adler function, using Pad\'{e} approximants,…

High Energy Physics - Lattice · Physics 2015-06-19 Bipasha Chakraborty , C. T. H. Davies , G. C. Donald , R. J. Dowdall , J. Koponen , G. P. Lepage , T. Teubner

We compute the leading, strong-interaction contribution to the anomalous magnetic moment of the electron, muon and tau using lattice quantum chromodynamics (QCD) simulations. Calculations include the effects of $u$, $d$, $s$ and $c$ quarks…

The persistent discrepancy of about 3.5 standard deviations between the experimental measurement and the Standard Model prediction for the muon anomalous magnetic moment, $a_\mu$, is one of the most promising hints for the possible…

High Energy Physics - Lattice · Physics 2020-05-20 H. Wittig , A. Gérardin , Marco Cè , G. von Hippel , B. Hörz , H. B. Meyer , K. Miura , D. Mohler , K. Ottnad , A. Risch , T. San José , J. Wilhelm

The electromagnetic coupling $\alpha$ and the electroweak mixing angle $\theta_{\mathrm{W}}$ are parameters of the Standard Model (SM) that enter precision SM tests and play a fundamental r\^ole in beyond SM physics searches. Their values…

We compare lattice data for the short-distance part of the static energy in 2+1 flavor quantum chromodynamics (QCD) with perturbative calculations, up to next-to-next-to-next-to leading-logarithmic accuracy. We show that perturbation theory…

High Energy Physics - Phenomenology · Physics 2013-05-30 Alexei Bazavov , Nora Brambilla , Xavier Garcia i Tormo , Peter Petreczky , Joan Soto , Antonio Vairo

We present a determination of the QCD coupling constant, $\alpha_s$, obtained by fitting lattice results for the flavour $ud$ hadronic vacuum polarisation function to continuum perturbation theory. We use $n_f=2+1$ flavours of Domain Wall…

High Energy Physics - Lattice · Physics 2018-07-09 Renwick J. Hudspith , Randy Lewis , Kim Maltman , Eigo Shintani

The measurement of the anomalous magnetic moment of the muon and its prediction allow for a high-precision test of the Standard Model (SM). In this proceedings article we present ongoing work combining lattice QCD and continuum QED in order…

High Energy Physics - Lattice · Physics 2019-11-14 Nils Asmussen , En-Hung Chao , Antoine Gérardin , Jeremy R. Green , Renwick J. Hudspith , Harvey B. Meyer , Andreas Nyffeler

We update our Standard Model predictions for g-2 of the muon and for the hadronic contributions to the running of the QED coupling, Delta alpha_had^(5)(M_Z^2). Particular emphasis is put on recent changes in the hadronic contributions from…

High Energy Physics - Phenomenology · Physics 2015-05-28 K. Hagiwara , R. Liao , A. D. Martin , Daisuke Nomura , T. Teubner

Puzzles in the determination of the hadronic-vacuum-polarization contribution currently impede a conclusive interpretation of the precision measurement of the anomalous magnetic moment of the muon at the Fermilab experiment. One such puzzle…

We propose a fully non-perturbative method to compute inelastic lepton-nucleon ($\ell N$) scattering cross sections using lattice QCD. The method is applicable even at low energies, such as the energy region relevant for the recent and…

High Energy Physics - Lattice · Physics 2021-01-04 Hidenori Fukaya , Shoji Hashimoto , Takashi Kaneko , Hiroshi Ohki

We reevaluate the hadronic contributions to the muon magnetic anomaly, and to the running of the electromagnetic coupling constant at the Z-boson mass. We include new pi+pi- cross-section data from KLOE, all available multi-hadron data from…

High Energy Physics - Phenomenology · Physics 2011-10-27 Michel Davier , Andreas Hoecker , Bogdan Malaescu , Zhiqing Zhang

The hadronic light-by-light scattering contribution to the muon anomalous magnetic moment, $(g-2$)/2, is computed in the infinite volume QED framework with lattice QCD. We report $a_\mu^\text{HLbL}=12.47(1.15)(0.95) \times 10^{-10}$ where…

High Energy Physics - Lattice · Physics 2024-12-09 Thomas Blum , Norman Christ , Masashi Hayakawa , Taku Izubuchi , Luchang Jin , Chulwoo Jung , Christoph Lehner , Cheng Tu