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We briefly sketch the methods for a numerically stable evaluation of tensor one-loop integrals that have been used in the calculation of the complete electroweak one-loop corrections to $\Pep\Pem\to4 $fermions. In particular, the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Dittmaier

We study a QED extension that is unitary, CPT invariant and super-renormalizable, but violates Lorentz symmetry at high energies, and contains higher-dimension operators (LVQED). Divergent diagrams are only one- and two-loop. We compute the…

High Energy Physics - Phenomenology · Physics 2010-05-12 Damiano Anselmi , Martina Taiuti

We investigate the relativistic dynamics of a spin half particle in the presence of a Lorentz-violating background within the framework of effective field theory. A modified Dirac Hamiltonian is considered, arising from a CPT odd coupling…

High Energy Physics - Phenomenology · Physics 2026-04-10 E. Maciel , M. A. Anacleto , K. E. L. Farias , E. Passos

We provide an explicit expression for the strong magnetic field limit of the Heisenberg-Euler effective Lagrangian for both scalar and spinor quantum electrodynamics. To this end, we show that the strong magnetic field behavior is fully…

High Energy Physics - Theory · Physics 2020-12-22 Felix Karbstein

We compute one-loop QCD corrections to the triple differential width of the inclusive decay $\bar{B} \to X_c \ell \bar{\nu}_\ell$ including contributions from all relevant dimension-six operators in the Weak Effective Theory (WET), at…

High Energy Physics - Phenomenology · Physics 2026-01-23 Alexandre Carvunis , Gael Finauri

The computation of one-loop corrections to the $\gamma^\star Q_+ q$ and $gR_+g$ effective vertices in the framework of gauge-invariant effective theory for Multi-Regge processes in QCD is reviewed. Due to consistent implementation of the…

High Energy Physics - Phenomenology · Physics 2019-05-29 Maxim Nefedov

Recently, Harlander et al.\ [Eur.\ Phys.\ J.\ C {\bf 78}, 944 (2018)] have computed the two-loop order (i.e., NNLO) coefficients in the gradient-flow representation of the energy--momentum tensor (EMT) in vector-like gauge theories. In this…

High Energy Physics - Lattice · Physics 2019-12-06 Takumi Iritani , Masakiyo Kitazawa , Hiroshi Suzuki , Hiromasa Takaura

This paper describes a method of numerical evaluating high-order QED contributions to the electron anomalous magnetic moment. The method is based on subtraction of infrared and ultraviolet divergences in Feynman-parametric space before…

High Energy Physics - Phenomenology · Physics 2018-11-07 Sergey Volkov

We use functional methods to compute one-loop effects in Heavy Quark Effective Theory. The covariant derivative expansion technique facilitates the efficient extraction of matching coefficients and renormalization group evolution equations.…

High Energy Physics - Phenomenology · Physics 2020-07-15 Timothy Cohen , Marat Freytsis , Xiaochuan Lu

We calculate analytically the improvement coefficients of the static axial and vector currents in O(a) improved lattice QCD at one-loop order of perturbation theory. The static quark is described by the hypercubic action, previously…

High Energy Physics - Lattice · Physics 2008-11-26 A. Grimbach , D. Guazzini , F. Knechtli , F. Palombi

We discuss new techniques developed in recent years for performing one-loop calculations in QCD, and present an example of results from the process 0 -> V q q-bar g g. Talk presented at the 1996 Zeuthen Workshop on Elementary Particle…

High Energy Physics - Phenomenology · Physics 2015-06-25 Z. Bern , L. Dixon , D. A. Kosower

The gradient-flow formulation of the energy-momentum tensor of QCD is extended to NNLO perturbation theory. This means that the Wilson coefficients which multiply the flowed operators in the corresponding expression for the regular…

High Energy Physics - Lattice · Physics 2025-05-14 Robert V. Harlander , Yannick Kluth , Fabian Lange

We compute new exact analytic expressions for one-loop scalar effective actions in Kerr (A)dS black hole (BH) backgrounds in four and five dimensions. These are computed by the connection coefficients of the Heun equation via a…

High Energy Physics - Theory · Physics 2025-01-14 Paolo Arnaudo , Giulio Bonelli , Alessandro Tanzini

A calculation of the one-loop self-energy and vacuum-polarization corrections to the hyperfine splitting of the 1s and 2s states in light H-like ions is carried out to all orders in the parameter Z \alpha. Using the known values for the Z…

Atomic Physics · Physics 2009-11-11 V. A. Yerokhin , A. N. Artemyev , V. M. Shabaev , G. Plunien

The first and second order form of gauge theories are classically equivalent; we consider the consequence of quantizing the first order form using the Faddeev-Popov approach. Both the Yang-Mills and the Einstein-Hilbert actions are…

High Energy Physics - Theory · Physics 2017-11-10 F. T. Brandt , D. G. C. McKeon

We applied the method of finite-part integration [Galapon E.A Proc.R.Soc A 473, 20160567(2017)] to evaluate in closed-form the exact one-loop integral representations of the Heisenberg-Euler Lagrangian from QED for a constant magnetic field…

Mathematical Physics · Physics 2024-02-20 Christian D. Tica , Eric A. Galapon

The technique of one-loop calculations for the processes involving Reggeized quarks is described in the framework of gauge invariant effective field theory for the Multi-Regge limit of QCD, which has been introduced by Lipatov and…

High Energy Physics - Theory · Physics 2017-12-06 Maxim Nefedov , Vladimir Saleev

We calculate the anomalous dimension of the $|\Delta S| = 1$ current-current operators of the weak effective Lagrangian at next-to-next-to-next-to-leading order (NNNLO) in QCD. This constitutes the first step towards a full four-loop…

High Energy Physics - Phenomenology · Physics 2026-04-21 Joachim Brod , Emmanuel Stamou , Tom Steudtner

We use the evolution operator method to find the one-loop effective action of scalar and spinor QED in electric field backgrounds in terms of the Bogoliubov coefficient between the ingoing and the outgoing vacua. We obtain the exact…

High Energy Physics - Theory · Physics 2008-12-18 Sang Pyo Kim , Hyun Kyu Lee , Yongsung Yoon

We introduce a Lorentz-symmetry violating extended quantum electrodynamics (QED) which preserves gauge symmetry. The extended fermionic sector can radiatively induce an extended effective action which simultaneously displays the same…

High Energy Physics - Theory · Physics 2017-08-29 M. A. Anacleto , F. A. Brito , O. Holanda , E. Passos