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Related papers: Study of the Couplings of QED and QCD from the Adl…

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The electromagnetic coupling receives significant contributions to its running from non-perturbative QCD effects. We present an update of a lattice QCD study of the Adler function and of its application to the determination of the running…

High Energy Physics - Lattice · Physics 2015-11-17 Anthony Francis , Vera Gülpers , Gregorio Herdoíza , Hanno Horch , Benjamin Jäger , Harvey B. Meyer , Hartmut Wittig

The QCD coupling appears in the perturbative expansion of the current-current two-point (vacuum polarization) function. Any lattice calculation of vacuum polarization is plagued by several competing non-perturbative effects at small momenta…

High Energy Physics - Lattice · Physics 2015-10-19 Renwick J. Hudspith , Randy Lewis , Kim Maltman , Eigo Shintani

We address several aspects of lattice QCD calculations of the hadronic vacuum polarization and the associated Adler function. We implement a representation derived previously which allows one to access these phenomenologically important…

High Energy Physics - Lattice · Physics 2013-09-11 Anthony Francis , Benjamin Jaeger , Harvey B. Meyer , Hartmut Wittig

We use a lattice determination of the hadronic vacuum polarization tensor to study the associated Ward identities and compute the Adler function. The vacuum polarization tensor is computed from a combination of point-split and local vector…

High Energy Physics - Lattice · Physics 2013-11-28 Hanno Horch , Michele Della Morte , Gregorio Herdoíza , Benjamin Jäger , Andreas Jüttner , Hartmut Wittig

The electromagnetic coupling constant, $\alpha$, is one of the fundamental parameters of the Standard Model (SM). Its value at the Z boson mass, $\alpha(M_Z)$, is of particular interest as it enters electroweak precision tests. When running…

High Energy Physics - Lattice · Physics 2024-01-09 Sophie Mutzel

We present an updated determination of the hadronic vacuum polarization contribution to the running of the electromagnetic coupling $\Delta\alpha_{\mathrm{had}}^{(5)}(-Q^2)$, and of the electroweak mixing angle in the space-like momentum…

As present and future experiments, on both the energy and precision frontiers, look to identify new physics beyond the Standard Model, we require more precise determinations of fundamental quantities, like the QED and electroweak couplings…

We present results for the hadronic running of the electromagnetic coupling and the weak mixing angle from simulations of lattice QCD with $N_f=2+1$ flavours of $O(a)$-improved Wilson fermions. Using two different discretisations of the…

We calculate the vacuum polarization functions on the lattice using the overlap fermion formulation.By matching the lattice data at large momentum scales with the perturbative expansion supplemented by Operator Product Expansion (OPE), we…

High Energy Physics - Lattice · Physics 2019-08-13 E. Shintani , S. Aoki , T. W. Chiu , S. Hashimoto , T. H. Hsieh , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , N. Yamada

I review the status of lattice QCD calculations of the hadronic contributions to the muon's anomalous magnetic moment, focussing on the hadronic vacuum polarisation contribution which dominates the uncertainty of the Standard Model…

High Energy Physics - Phenomenology · Physics 2023-06-21 Hartmut Wittig

We present an updated version of a QCD coupling which fulfills various physically motivated conditions: at high momenta it practically coincides with the perturbative QCD (pQCD) coupling; at intermediate momenta it reproduces correctly the…

High Energy Physics - Phenomenology · Physics 2021-05-26 Gorazd Cvetic , Reinhart Kogerler

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 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

The energy dependency (running) of the strength of electromagnetic interactions $\alpha$ plays an important role in precision tests of the Standard Model. The running of the former to the $Z$ pole is an input quantity for global electroweak…

We present an update of our lattice QCD determination of the hadronic contribution to the running of the electromagnetic coupling, $\Delta\alpha_{\mathrm{had}}^{(5)}(-Q^2)$, and of the electroweak mixing angle in the space-like momentum…

Non-perturbatively computing the hadronic vacuum polarization at large photon virtualities and making contact with perturbation theory enables a precision determination of the electromagnetic coupling at the $Z$ pole, which enters global…

High Energy Physics - Lattice · Physics 2022-01-19 Marco Cè , Tim Harris , Harvey B. Meyer , Arianna Toniato , Csaba Török

We present an update of our lattice QCD study of the vacuum polarization function using O$(a)$-improved $N_ {\rm f} =2$ Wilson fermions with increased statistics and a large set of momenta. The resulting points are highly correlated and…

High Energy Physics - Lattice · Physics 2016-02-15 Michele Della Morte , Gregorio Herdoiza , Hanno Horch , Benjamin Jäger , Harvey Meyer , Hartmut Wittig

An experimental motivated QCD analysis of the behaviour of the Adler D-function in the Euclidian region is described. It is stressed that by taking account of $b$-quark mass-dependent $\alpha_s^2$-effects one obtains better agreement…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. L. Kataev

The quark-connected leading-order hadronic contributions to the running of the electromagnetic fine structure constant, $\alpha_{\rm QED}$, and the weak mixing angle, $\theta_W$, are determined by a four-flavour lattice QCD computation with…

High Energy Physics - Lattice · Physics 2015-12-09 Florian Burger , Karl Jansen , Marcus Petschlies , Grit Pientka

The experimental uncertainty on the anomalous magnetic moment of the muon has been significantly reduced with the recent results of the Fermilab $g-2$ experiment, and a further reduction is expected in the near future. The precision of the…

High Energy Physics - Lattice · Physics 2024-01-30 Simon Kuberski
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