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Related papers: Electroweak effective couplings for future precisi…

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We report on our update to [1] on the hadronic running of electroweak couplings from $O(a)$-improved Wilson fermions with $N_f=2+1$ flavours. The inclusion of additional ensembles at very fine lattice spacings together with a number of…

High Energy Physics - Lattice · Physics 2025-02-17 Alessandro Conigli , Georg von Hippel , Simon Kuberski , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

I review the results of a recent global fit to electroweak precision data. Particular attention is devoted to the landscape of determinations of the weak mixing angle, recent results on basic properties of the electroweak gauge bosons, and…

High Energy Physics - Phenomenology · Physics 2025-05-07 Jens Erler

We consider a recent proposal by Dimopoulos and Kaplan to embed the electroweak SU(2)_L X U(1)_Y into a larger group SU(3)_W X SU(2) X U(1) at a scale above a TeV. This idea is motivated by the prediction for the weak mixing angle sin^2…

High Energy Physics - Phenomenology · Physics 2009-09-17 Csaba Csaki , Joshua Erlich , Graham D. Kribs , John Terning

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…

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

We explore the effects of a heavy fermion doublet in a simplified version of the standard electroweak theory. We integrate out the doublet and compute the exact effective energy functional of spatially varying gauge and Higgs fields. We…

High Energy Physics - Theory · Physics 2009-11-10 E. Farhi , N. Graham , R. L. Jaffe , V. Khemani , H. Weigel

In quantum electrodynamics with fermions f = e,\mu..., knowledge of the vacuum polarization spectral function determined from the tree level e^+e^- -> f^+f^- cross sections, together with a single low energy measurement of the fine…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Papavassiliou , E. de Rafael , N. J. Watson

The HERA experiments have collected interesting luminosity samples with both polarized and unpolarized lepton beams. The polarized CC data are directly sensitive to right handed charged currents. The data are in agreement with the SM…

High Energy Physics - Experiment · Physics 2014-11-17 Juraj Bracinik

We review the determination of the QED coupling at the Z pole, which is a crucial parameter for electroweak theory. We include recent e+e- -> hadron data from Novosibirsk and Beijing to re-evaluate alpha (M_Z^2). We find 1/alpha (M_Z^2) =…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Martin , J. Outhwaite , M. G. Ryskin

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…

It is found that in presence of electroweak interactions the gauge covariant diagonalization of the axial-vector -- pseudoscalar mixing in the effective meson Lagrangian leads to a deviation from the vector meson and the axial-vector meson…

High Energy Physics - Phenomenology · Physics 2018-12-26 A. A. Osipov , B. Hiller , P. M. Zhang

The measurements resulting from the analysis of the LEP2 data have brought more strong evidence in support of the standard electroweak model. In particular the LEP2 data has revealed (i) the first determination of the SU(2) gauge bosons…

High Energy Physics - Experiment · Physics 2007-05-23 Paolo Azzurri

Recent improvements in the low energy e+e- annihilation data and their influence on the determination of the hadronic contribution to the running of the QED fine structure constant at m_Z are discussed. Using CMD-2 and KLOE measurements in…

High Energy Physics - Phenomenology · Physics 2009-11-11 H. Burkhardt , B. Pietrzyk

One of the most precise measurements of the strong coupling constant alpha_s(MZ) is obtained in the context of global analyses of precision electroweak data. This article reviews the sensitivity of different electroweak observables to…

High Energy Physics - Phenomenology · Physics 2009-11-11 H. Stenzel

The complete calculation of the 2-loop electroweak corrections to the renormalization of the electric charge in the Standard Model allows to discuss in detail the value of the MSbar effective coupling $\hat e(m_Z)$. We discuss the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Alessandro Vicini

We compute the effects of anomalous gauge-boson couplings at high-energy hadron colliders using next-to-leading order $SU(2) \times SU(2)$ chiral perturbation theory. By comparing the yields from the universal $p^2$ terms with those arising…

High Energy Physics - Phenomenology · Physics 2009-10-22 J. Bagger , S. Dawson , G. Valencia

In order to reduce the current hadronic uncertainties in the theory prediction for the anomalous magnetic moment of the muon, lattice calculations need to reach sub-percent accuracy on the hadronic-vacuum-polarization contribution. This…

High Energy Physics - Lattice · Physics 2019-07-31 J. Bijnens , J. Harrison , N. Hermansson-Truedsson , T. Janowski , A. Jüttner , A. Portelli

The quantization of the SU(2)$\times $U(1) gauge-symmetric electroweak theory is performed in the Hamiltonian path-integral formalism. In this quantization, we start from the Lagrangian given in the unitary gauge in which the unphysical…

High Energy Physics - Theory · Physics 2007-05-23 Jun-Chen Su

The measured values of two electroweak gauge couplings appear to obey an approximate 5% SU(3) relation. Unless this is an accident caused by fortuitous Planck-scale physics, it suggests the presence of an SU(3) symmetry near the electroweak…

High Energy Physics - Phenomenology · Physics 2009-11-07 Savas Dimopoulos , David Elazzar Kaplan

We derive logarithmically enhanced two-loop virtual electroweak corrections for arbitrary fermion-scattering processes at the TeV scale. This extends results previously obtained for massless fermion scattering to processes that involve also…

High Energy Physics - Phenomenology · Physics 2009-11-19 Ansgar Denner , Bernd Jantzen , Stefano Pozzorini