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The short-distance behaviour of the hadronic light-by-light (HLbL) contribution to $(g-2)_{\mu}$ has recently been studied by means of an operator product expansion in a background electromagnetic field. The leading term in this expansion…

High Energy Physics - Phenomenology · Physics 2021-05-12 Johan Bijnens , Nils Hermansson-Truedsson , Laetitia Laub , Antonio Rodríguez-Sánchez

We present results for the short-distance window observable of the hadronic vacuum polarization contribution to the muon $g-2$, computed via the time-momentum representation (TMR) in lattice QCD. A key novelty of our calculation is the…

High Energy Physics - Lattice · Physics 2024-01-23 Simon Kuberski , Marco Cè , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Andreas Risch , Hartmut Wittig

We present a quenched lattice calculation of the lowest order (alpha^2) hadronic contribution to the anomalous magnetic moment of the muon which arises from the hadronic vacuum polarization. A general method is presented for computing…

High Energy Physics - Lattice · Physics 2009-11-07 T. Blum

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 2009-10-28 Morris L. Swartz

The hadronic vacuum-polarization contribution to the muon anomalous magnetic moment a_{mu}(hadr) and to the value of the eleectromagnetic coupling constant at q^2 = M^2_z are determined more precisely in connection with a new more exact…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. V. Geshkenbein

We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the $Z$-boson mass. We include newest $e^+e^- \to$ hadrons cross-section data together…

High Energy Physics - Phenomenology · Physics 2020-03-19 M. Davier , A. Hoecker , B. Malaescu , Z. Zhang

We present the first lattice QCD calculation of the next-to-leading order hadronic vacuum polarization contribution to the muon anomalous magnetic moment with sub-percent precision. We employ the time-momentum representation for the…

High Energy Physics - Lattice · Physics 2026-04-13 Arnau Beltran , Alessandro Conigli , Simon Kuberski , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

Comparing perturbative calculations with a lattice computation of the static energy in quantum chromodynamics at short distances, we obtain a determination of the strong coupling alpha_s. Our determination is performed at a scale of around…

High Energy Physics - Phenomenology · Physics 2012-08-27 Xavier Garcia i Tormo

We compute the hadronic light-by-light scattering contribution to the muon $g-2$ from the up, down, and strange-quark sector directly using lattice QCD. Our calculation features evaluations of all possible Wick-contractions of the relevant…

High Energy Physics - Lattice · Physics 2021-08-18 En-Hung Chao , Renwick J. Hudspith , Antoine Gérardin , Jeremy R. Green , Harvey B. Meyer , Konstantin Ottnad

Perturbative expansions of several small Wilson loops are computed through next-to-next-to-leading order in unquenched lattice QCD, from Monte Carlo simulations at weak couplings. This approach provides a much simpler alternative to…

High Energy Physics - Lattice · Physics 2009-11-11 Kit Yan Wong , Howard D. Trottier , R. M. Woloshyn

A recent lattice calculation of the QCD running coupling is presented. The coupling is extracted from the force between two static quarks in the framework of the valence quark approximation. A value of the Lambda-parameter for zero quark…

High Energy Physics - Lattice · Physics 2009-09-25 Gunnar S. Bali

A key issue affecting the attempt to reduce the uncertainty on the Standard Model prediction for the muon anomalous magnetic moment is the current discrepancy between lattice-QCD and data-driven results for the hadronic vacuum polarization.…

High Energy Physics - Phenomenology · Physics 2024-11-19 Genessa Benton , Diogo Boito , Maarten Golterman , Alexander Keshavarzi , Kim Maltman , Santiago Peris

We discuss our present knowledge of $\alpha_s$, the fundamental running coupling or effective charge of Quantum Chromodynamics (QCD). A precise understanding of the running of $\alpha_s(Q^2) $ at high momentum transfer, $Q$, is necessary…

High Energy Physics - Phenomenology · Physics 2023-12-04 A. Deur , S. J. Brodsky , C. D. Roberts

The leading order hadronic contribution to the muon magnetic moment anomaly, $a^{HAD}_\mu$, is determined entirely in the framework of QCD. The result in the light-quark sector, in units of $10^{-10}$, is $a^{HAD}_\mu|_{uds} =686 \pm 26$,…

High Energy Physics - Phenomenology · Physics 2018-03-14 C. A. Dominguez , K. Schilcher , H. Spiesberger

Three-flavor lattice QCD simulations and two-loop perturbation theory are used to make the most precise determination to date of the strange-, up-, and down-quark masses, $m_s$, $m_u$, and $m_d$, respectively. Perturbative matching is…

High Energy Physics - Phenomenology · Physics 2008-11-26 Quentin Mason , Howard D. Trottier , Ron Horgan , Christine T. H. Davies , G. Peter Lepage

The leading hadronic contributions to the anomalous magnetic moments of the electron and the $\tau$-lepton are determined by a four-flavour lattice QCD computation with twisted mass fermions. The continuum limit is taken and systematic…

High Energy Physics - Lattice · Physics 2016-09-21 Florian Burger , Karl Jansen , Marcus Petschlies , Grit Pientka

The QCD running coupling $\alpha_s(Q^2)$ sets the strength of the interactions of quarks and gluons as a function of the momentum transfer $Q$. The $Q^2$ dependence of the coupling is required to describe hadronic interactions at both large…

High Energy Physics - Phenomenology · Physics 2017-04-07 A. Deur , S. J. Brodsky , G. F. de Teramond

A review of the calculations of the proton's spin using lattice QCD is presented. Results for the three contributions, the quark contribution $\sum_{q=u,d,s,c} (\frac{1}{2} {\Delta q})$, the total angular momentum of the quarks $J_q$ and of…

High Energy Physics - Lattice · Physics 2019-04-02 Rajan Gupta

Lepton number violating meson decays, such as $M_1^- \to M_2^+\ell_1^-\ell_2^-$, provide constraints on $d=9$ $\Delta L = 2$ operators. RGE-improved bounds on the Wilson coefficients of these operators have been presented in the literature,…

High Energy Physics - Phenomenology · Physics 2025-10-30 Andrea Donini , Marcela González , Martin Hirsch , Nicolás A. Neill

QCD bounds on the leading-order (LO) hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon ($a_\mu^{\mathrm{HVP,LO}}$, $a_\mu=\left(g-2\right)_\mu/2$) are determined by imposing H\"older inequalities…

High Energy Physics - Phenomenology · Physics 2024-08-01 Siyuan Li , T. G. Steele , J. Ho , R. Raza , K. Williams , R. T. Kleiv
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