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Related papers: Vertex diagrams for the QED form factors at the 2-…

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In order to investigate the systematics of the loop expansion in high temperature gauge theories beyond the leading order hard thermal loop (HTL) approximation, we calculate the two-loop electron proper self-energy in high temperature QED.…

High Energy Physics - Phenomenology · Physics 2010-04-06 Emil Mottola , Zsolt Szep

We compute the master integrals containing 2 and 3 massive propagators entering the planar amplitudes of the 2-loop electroweak form factor. The masses of the $W$, $Z$ and Higgs bosons are assumed to be degenerate. This work is a…

High Energy Physics - Phenomenology · Physics 2009-11-10 U. Aglietti , R. Bonciani

We discuss the structure of infrared singularities in on-shell QCD amplitudes at two-loop order. We present a general factorization formula that controls all the $\ep$-poles of the dimensionally regularized amplitudes. The dependence on the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Stefano Catani

Analytical expressions for the tenth order electromagnetic corrections to the lepton ($L=e, ~\mu $ and $\tau$) anomaly $a_L$ are derived explicitly for a class of Feynman diagrams with insertions of the vacuum polarization operator…

High Energy Physics - Phenomenology · Physics 2024-06-25 O. P. Solovtsova , V. I. Lashkevich , L. P. Kaptari

We apply a recently suggested new strategy to solve differential equations for master integrals for families of Feynman integrals. After a set of master integrals has been found using the integration-by-parts method, the crucial point of…

High Energy Physics - Theory · Physics 2015-06-16 Johannes M. Henn , Alexander V. Smirnov , Vladimir A. Smirnov

Loop calculations involve the evaluation of divergent integrals. Usually [1] one computes them in a number of dimensions different than four where the integral is convergent and then one performs the analytical continuation and considers…

High Energy Physics - Phenomenology · Physics 2009-10-31 Francesco Caravaglios

We describe the calculation of all planar master integrals that are needed for the computation of NNLO QCD corrections to the production of two off-shell vector bosons in hadron collisions. The most complicated representatives of integrals…

High Energy Physics - Phenomenology · Physics 2015-06-18 Johannes M. Henn , Kirill Melnikov , Vladimir A. Smirnov

QCD in non-integer d=4-2 epsilon space-time dimensions possesses a nontrivial critical point and enjoys exact scale and conformal invariance. This symmetry imposes nontrivial restrictions on the form of the renormalization group equations…

High Energy Physics - Phenomenology · Physics 2015-06-19 V. M. Braun , A. N. Manashov

We complete the analytic evaluation of the master integrals for the two-loop non-planar box diagrams contributing to the top-pair production in the quark-initiated channel, at next-to-next-to-leading order in QCD. The integrals are…

High Energy Physics - Phenomenology · Physics 2022-10-12 Stefano Di Vita , Thomas Gehrmann , Stefano Laporta , Pierpaolo Mastrolia , Amedeo Primo , Ulrich Schubert

We have evaluated with 1100 digits of precision the contribution of all the 891 mass-independent four-loop Feynman diagrams contributing to the slope of the Dirac form factor in QED. The total 4-loop contribution is $ m^2 F_1^{(4)'}(0) =…

High Energy Physics - Phenomenology · Physics 2019-12-11 Stefano Laporta

In this paper, we evaluate the electromagnetic and gravitational form factors as well as the corresponding generalized parton distributions of the electron using the Basis Light-front Quantization approach to QED. We compare our results…

High Energy Physics - Phenomenology · Physics 2024-05-28 Lingdi Meng , Shuo Tang , Zhi Hu , Guo-Li Wang , Yang Li , Xingbo Zhao , James P. Vary

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 electric field…

Mathematical Physics · Physics 2024-10-29 Christian D. Tica , Eric A. Galapon

We consider two-loop renormalization of high-dimensional Lorentz scalar operators in the gluonic sector of QCD. These operators appear also in the Higgs effective theory obtained by integrating out the top quark loop in the gluon fusion…

High Energy Physics - Phenomenology · Physics 2021-05-05 Qingjun Jin , Ke Ren , Gang Yang

We present the complete analytical result for the two-loop logarithmically enhanced contributions to the high energy asymptotic behavior of the vector form factor and the four-fermion cross section in a spontaneously broken SU(2) gauge…

High Energy Physics - Phenomenology · Physics 2014-11-18 Bernd Jantzen , Johann H. Kühn , Alexander A. Penin , Vladimir A. Smirnov

We review the current status of perturbative corrections in QCD at four loops for scattering processes with space- and time-like kinematics at colliders, with specific focus on deep-inelastic scattering and electron-positron annihilation.…

High Energy Physics - Phenomenology · Physics 2021-04-19 S. Moch , V. Magerya

We consider quantum electrodynamics (QED) corrections to the fine splitting $E(2P_{3/2}) - E(2P_{1/2})$ in the Li atom. We derive complete formulas for the $m\,\alpha^6$ and $m\,\alpha^7\,\ln\alpha$ contributions and calculate them…

Atomic Physics · Physics 2015-06-19 Mariusz Puchalski , Krzysztof Pachucki

We calculate the complete set of two-loop Master Integrals with two off mass-shell legs with massless internal propagators, that contribute to amplitudes of diboson $V_1V_2$ production at the LHC. This is done with the Simplified…

High Energy Physics - Phenomenology · Physics 2015-07-22 Costas G. Papadopoulos , Damiano Tommasini , Christopher Wever

We calculate the gravitational form factors of the electron at one loop in quantum electrodynamics, decomposing these into contributions from the electron and photon parts of the energy-momentum tensor. Ultraviolet divergences are removed…

High Energy Physics - Phenomenology · Physics 2023-02-20 Adam Freese , Andreas Metz , Barbara Pasquini , Simone Rodini

We present the analytic calculation of the Master Integrals for the two-loop, non-planar topologies that enter the calculation of the amplitude for top-quark pair hadroproduction in the quark-annihilation channel. Using the method of…

High Energy Physics - Phenomenology · Physics 2019-09-04 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Andrea Ferroglia , Simone Lavacca , Andreas von Manteuffel

The two-loop electron self-energy correction is one of the most problematic QED effects and, for a long time, was the dominant source of uncertainty in the theoretical prediction of the bound-electron $g$ factor in hydrogen-like ions. A…

Atomic Physics · Physics 2025-12-08 V. A. Yerokhin , B. Sikora , Z. Harman , C. H. Keitel