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Related papers: The Vacuum Polarization Function to O(alpha^2) Acc…

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Because of the infrared renormalons, it is difficult to get power accuracy in the traditional approach to the Wilson's operator product expansion. Based on a new perturbative renormalization scheme for power-divergent operators, I propose a…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xiangdong Ji

We present results for the QED and strong isospin breaking corrections to the hadronic vacuum polarization using $N_f=2+1$ Domain Wall fermions. QED is included in an electro-quenched setup using two different methods, a stochastic and a…

High Energy Physics - Lattice · Physics 2018-04-18 Peter Boyle , Vera Gülpers , James Harrison , Andreas Jüttner , Christoph Lehner , Antonin Portelli , Christopher Sachrajda

We consider, at order $\alpha_s^2$ in the QCD coupling, top-quark pair production in the continuum at various center-of-mass energies and $b$-quark pair production at the $Z$ resonance by (un)polarized electron and positron beams. For top…

High Energy Physics - Phenomenology · Physics 2023-05-22 Werner Bernreuther , Long Chen , Peng-Cheng Lu , Zong-Guo Si

We examine the vacuum polarization contribution in the renormalization scheme of QED. Normally, the quadratic divergence term is discarded under the condition that the counter term of the Lagrangian density should be gauge invariant. Here,…

High Energy Physics - Theory · Physics 2009-01-23 T. Fujita , N. Kanda , H. Kato , H. Kubo , Y. Munakata , S. Oshima , K. Tsuda

The leading nonperturbative effects to the fine and hyperfine splitting were calculated some time ago. Recently, they have been used in order to obtain realistic numerical results for the lower levels in bottomonium systems. We point out…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Pineda

Employing the heavy quark pole mass and static potential that were obtained from resummation of the renormalon-caused large order behavior to all orders, and matching the resummed static potential to the long distance Cornell potential we…

High Energy Physics - Phenomenology · Physics 2007-05-23 C. S. Kim , Taekoon Lee , Guo-Li Wang

In order to determine polarized parton distributions we have made a new NLO QCD fit using all experimental data on spin asymmetries measured in the deep inelastic scattering on different nucleon targets. The functional form of such…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Bartelski , S. Tatur

We evaluate the O(alpha) QED corrections to the recoil electron energy spectrum in the process nu_l + e --> nu_l + e (+gamma), where (+gamma) indicates the possible emission of a photon and l=e, mu or tau. The soft and hard bremsstrahlung…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Passera

A previous calculation of electroweak O(alpha) corrections to deep-inelastic neutrino scattering, as e.g. measured by NuTeV and NOMAD, is supplemented by higher-order effects. In detail, we take into account universal two-loop effects from…

High Energy Physics - Phenomenology · Physics 2009-11-11 K. -P. O. Diener , S. Dittmaier , W. Hollik

We compute the leading $\alpha_s$ corrections to the two-point correlator of the $O_{\Delta B=2}$ operator which controls the $B^0 \bar B^0$ mixing. Using this result within the QCD spectral sum rules approach and some phenomenologically…

High Energy Physics - Phenomenology · Physics 2010-11-01 S. Narison , A. A. Pivovarov

We present the complete calculations of the forward-backward asymmetry ($A_{\rm FB}$) and the total cross section of top quark pair production induced by dimension-six four quark operators at the Tevatron up to…

High Energy Physics - Phenomenology · Physics 2015-05-28 Ding Yu Shao , Chong Sheng Li , Jian Wang , Jun Gao , Hao Zhang , Hua Xing Zhu

The total two-photon decay rate of hydrogen-like ions is studied using relativistic quantum electrodynamics. In particular, we analyse how finite nuclear size and QED vacuum polarization corrections affect the decay rate. To calculate these…

Atomic Physics · Physics 2020-10-21 J. Sommerfeldt , R. A. Müller , A. V. Volotka , S. Fritzsche , A. ~Surzhykov

We calculate vacuum polarization corrections to the binding energies in neutral alkali atoms Na through to the superheavy element E119. We employ the relativistic Hartree-Fock method to demonstrate the importance of relaxation of the…

Atomic Physics · Physics 2016-05-04 J. S. M. Ginges , J. C. Berengut

The results of a recent next-to-leading order QCD analysis of the world data on polarized deep inelastic scattering are reported. New parameterizations are derived for the quark and gluon distributions, accounting for the massive Wilson…

High Energy Physics - Phenomenology · Physics 2015-05-20 Johannes Blümlein , Helmut Böttcher

The results of perturbative QCD evaluation of the ~m_f^2/M_Z^2 contributions to the decay rates in Z--->bb and Z--->hadrons for the quark masses m_f << M_Z are presented. The recent results due to the combination of renormalization group…

High Energy Physics - Phenomenology · Physics 2009-10-28 Levan R. Surguladze

Second order ${\cal O}(\alpha_s^2)$ corrections to the heavy quark production cross-section due to massless quarks and coloured scalars are calculated for all energies above threshold. Based on the method introduced in this letter also the…

High Energy Physics - Phenomenology · Physics 2009-10-28 K. G. Chetyrkin , A. H. Hoang , J. H. Kuehn , M. Steinhauser , T. Teubner

Recent evaluations of the hadronic vacuum polarization contributions to the effective fine-structure constant alpha_{em}(M_Z) are summarized and commented. A new update based on corrected CMD-2 data is presented. My new estimates are Delta…

High Energy Physics - Phenomenology · Physics 2007-05-23 F. Jegerlehner

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

We introduce a new method for calculating the ${\rm O}(\alpha^3)$ hadronic-vacuum-polarization contribution to the muon anomalous magnetic moment from ${ab-initio}$ lattice QCD. We first derive expressions suitable for computing the…

High Energy Physics - Lattice · Physics 2018-11-14 Bipasha Chakraborty , Christine T. H. Davies , Jonna Koponen , G. Peter Lepage , Ruth S. Van de Water

The results of a recent next-to-leading order QCD analysis of the world data on polarized deep inelastic scattering are reported. New parameterizations are derived for the quark and gluon distributions and the value of $\alpha_s(M_z^2)$ is…

High Energy Physics - Phenomenology · Physics 2010-11-19 Johannes Blümlein , Helmut Böttcher