Recent progress in computing four-loop massive correlators

Abstract

We report about recent progress in computing four-loop massive correlators. The expansion of these correlators in the external momentum leads to vacuum integrals. The calculation of these vacuum integrals can be used to determine Taylor expansion coefficients of the vacuum polarization function and decoupling functions in perturbative Quantum chromodynamics. New results at four-loop order for the lowest Taylor expansion coefficient of the vacuum polarization function and for the decoupling relation are presented.

4 pages, talk given at the 12th International Conference on Quantum Chromodynamics, Montpellier, 4-8th July 2005

References in corpus (20)

• The four-loop beta-function in Quantum Chromodynamics
• New features of FORM
• The Four-Loop QCD Beta-Function and Anomalous Dimensions
• The analytical value of the electron (g-2) at order alpha^3 in QED
• Decoupling Relations to O(alpha_s^3) and their Connection to Low-Energy Theorems
• Strong Coupling Constant with Flavour Thresholds at Four Loops in the MS-bar Scheme
• Three-Loop Polarization Function and $\mathcal{O}({\alpha }_s^2)$ Corrections to the Production of Heavy Quarks
• MATAD: a program package for the computation of MAssive TADpoles
• Heavy Quark Current Correlators to O(α_s^2)
• Determination of ${\alpha }_s$ and heavy quark masses from recent measurements of $R(s)$
• Calculation of Feynman Diagrams from their Small Momentum Expansion
• High-precision epsilon expansions of single-mass-scale four-loop vacuum bubbles
• Two-Loop Gluon-Condensate Contributions To Heavy-Quark Current Correlators: Exact Results And Approximations
• ep-Finite Basis of Master Integrals for the Integration-By-Parts Method
• Automatic reduction of four-loop bubbles
• Singlet Polarization Functions at O(α_s^2)
• Tuning FORM with large calculations
• Heavy-quark vacuum polarization: first two moments of the O(alphas^3 nf^2) contribution
• Application of conformal mapping and Padé approximants $(\omega P^{\prime }s)$ to the calculation of various two-loop Feynman diagrams
• Correlator of heavy-quark currents at small q^2 in the large-beta_0 limit