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Predicting the $B_s^0-\bar{B}_s^0$ width difference $\Delta\Gamma_s$ relies on the heavy quark expansion and on hadronic matrix elements of $\Delta B=2$ operators. We present the first lattice QCD results for matrix elements of the…

High Energy Physics - Lattice · Physics 2020-02-27 Christine T. H. Davies , Judd Harrison , G. Peter Lepage , Christopher J. Monahan , Junko Shigemitsu , Matthew Wingate

We calculate the leading-order hadronic correction to the anomalous magnetic moments of each of the three charged leptons in the Standard Model: the electron, muon and tau. Working in two-flavor lattice QCD, we address essentially all…

High Energy Physics - Lattice · Physics 2011-05-27 Dru B. Renner , Xu Feng , Karl Jansen , Marcus Petschlies

The QCD-coupling is a necessary input in the computation of many observables, and the parametric error on input parameters can be a dominant source of uncertainty. The coupling can be extracted by comparing high order perturbative…

High Energy Physics - Lattice · Physics 2022-03-16 Leonardo Chimirri , Rainer Sommer

We present O(g^4) calculations of both planar and non-planar Wilson loops for various actions in the presence of sea quarks. In particular, the plaquette, the static potential and the static self energy are calculated to this order for…

High Energy Physics - Lattice · Physics 2007-05-23 Gunnar S. Bali , Peter Boyle

We compute the hadronic running of the electromagnetic and weak couplings in lattice QCD with $N_{\mathrm{f}}=2+1$ flavors of $\mathcal{O}(a)$ improved Wilson fermions. Using two different discretizations of the vector current, we compute…

We present a lattice calculation of the leading hadronic contribution to the anomalous magnetic moment of the muon. This work is based on a subset of the CLS ensembles with $N_f = 2+1$ dynamical quarks and a quenched charm quark. Noise…

The contribution from hadronic vacuum polarisation effects is responsible for a large fraction of the theoretical uncertainty in the running of the QED coupling. The current level of uncertainty has become a limitation for electroweak…

High Energy Physics - Lattice · Physics 2014-12-23 Anthony Francis , Gregorio Herdoíza , Hanno Horch , Benjamin Jäger , Harvey B. Meyer , Hartmut Wittig

After a brief self-contained introduction to the muon anomalous magnetic moment, (g-2), we review the status of lattice calculations of the hadronic vacuum polarization contribution and present first results from lattice QCD for the…

High Energy Physics - Lattice · Physics 2013-01-15 T. Blum , M. Hayakawa , T. Izubuchi

We obtain a new value for the QCD coupling constant by combining lattice QCD simulations with experimental data for hadron masses. Our lattice analysis is the first to: 1) include vacuum polarization effects from all three light-quark…

High Energy Physics - Lattice · Physics 2009-11-11 Q. Mason , H. D. Trottier , C. T. H. Davies , K. Foley , A. Gray , G. P. Lepage , M. Nobes , J. Shigemitsu

We present results for the leading hadronic contribution to the muon anomalous magnetic moment due to strange quark-connected vacuum polarisation effects. Simulations were performed using RBC--UKQCD's $N_f=2+1$ domain wall fermion ensembles…

We present the first purely theoretical calculation of the weak mixing angle in the MS scheme at low energies by combining results from lattice QCD with perturbation theory. We discuss its correlation with the hadronic contribution to the…

High Energy Physics - Phenomenology · Physics 2024-06-25 Jens Erler , Rodolfo Ferro-Hernandez , Simon Kuberski

This work presents a complete re-evaluation of the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, $a_{\mu}^{\rm had, \, VP}$ and the hadronic contributions to the effective QED coupling at the mass…

High Energy Physics - Phenomenology · Physics 2018-07-16 Alexander Keshavarzi , Daisuke Nomura , Thomas Teubner

The anomalous magnetic moment of the muon, a_mu, has been measured with an overall precision of 540 ppb by the E821 experiment at BNL. Since the publication of this result in 2004 there has been a persistent tension of 3.5 standard…

High Energy Physics - Lattice · Physics 2019-01-15 Harvey B. Meyer , Hartmut Wittig

The leading-order hadronic contribution to the muon anomalous magentic moment, $a_\mu^{\rm LO,HVP}$, can be expressed as an integral over Euclidean $Q^2$ of the vacuum polarization function. We point out that a simple trapezoid-rule…

High Energy Physics - Lattice · Physics 2014-10-31 Maarten Golterman , Kim Maltman , Santiago Peris

A QCD model with an infinite number of vector mesons suggested by one of the authors is used to derive the value of the correction $\delta\alpha_{hadr}$ for $\alpha(m_{Z}^{2})$ due to the strong interactions. The result is…

High Energy Physics - Phenomenology · Physics 2009-10-28 B. V. Geshkenbein , V. L. Morgunov

We give a short description of the present situation of lattice QCD simulations. We then focus on the computation of the anomalous magnetic moment of the muon using lattice techniques. We demonstrate that by employing improved observables…

High Energy Physics - Lattice · Physics 2015-06-03 X. Feng , K. Jansen , M. Petschlies , D. Renner

We present the results of a new evaluation of the anomalous magnetic moment a_mu=(g_mu-2)/2 of the muon where the role of input data needed in the evaluation is lowered in the interval between 1.2 and 3.0 GeV below charm threshold. This is…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Groote , J. G. Körner , J. Maul

We present a lattice determination of the $\Lambda$ parameter in three-flavor QCD and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in the range from $0.2\,$GeV to $70\,$GeV, and using…

High Energy Physics - Lattice · Physics 2017-09-13 M. Bruno , M. Dalla Brida , P. Fritzsch , T. Korzec , A. Ramos , S. Schaefer , H. Simma , S. Sint , R. Sommer

A novel approach towards the hadronic contributions to the anomalous magnetic moment of the muon $a_{\mu}$ is presented, namely the Dyson-Schwinger equations of QCD. It has the advantage of being valid for all momentum scales and has the…

High Energy Physics - Phenomenology · Physics 2015-05-20 Tobias Goecke , Christian S. Fischer , Richard Williams

In contrast to perturbative QCD, the analytic QCD models have running coupling whose analytic properties correctly mirror those of spacelike observables. The discontinuity (spectral) function of such running coupling is expected to agree…

High Energy Physics - Phenomenology · Physics 2012-07-04 César Ayala , Carlos Contreras , Gorazd Cvetič