منابع مشابه
Complete One-Loop Amplitudes With Massless Propagators
A general one-loop scattering amplitude may be expanded in terms of master integrals. The coefficients of the master integrals can be obtained from tree-level input in a two-step process. First, use known formulas to write the coefficients of (4−2ǫ)-dimensional master integrals; these formulas depend on an additional variable, u, which encodes the dimensional shift. Second, convert the u-depend...
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We present numerical results which are needed to evaluate all nontrivial master integrals for four-loop massless propagators, confirming the recent analytic results of [1] and evaluating an extra order in ε expansion for each master integral. E-mail: [email protected] E-mail: [email protected]
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The physical motivations have been discussed extensively in the reports of the recent years. Thus, we only would like to mention that the problems treated within this project aim for the evaluation of so-called Feynman diagrams which in turn lead to quantum corrections within a given quantum field theory like Quantum Electrodynamics or Quantum Chromodynamics but also supersymmetric theories. Am...
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We report on two recent results based on the evaluation of five-loop massless propagators in QCD and QED: (i) corrections of order α 4 s to the absorptive part of the polarization function in QCD with n f = 3; (ii) the five-loop contribution to the β function of quenched QED.
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Inspired by the corresponding problem in QCD, we determine the pressure of massless O(N) scalar field theory up to order g 6 in the weak-coupling expansion, where g 2 denotes the quartic coupling constant. This necessitates the computation of all 4-loop vacuum graphs at a finite temperature: by making use of methods developed by Arnold and Zhai at 3-loop level, we demonstrate that this task is ...
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ژورنال
عنوان ژورنال: Journal of High Energy Physics
سال: 2019
ISSN: 1029-8479
DOI: 10.1007/jhep12(2019)026