Heidelberg 2007 – scientific programme
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T: Fachverband Teilchenphysik
T 206: QCD Theorie I
T 206.6: Talk
Tuesday, March 6, 2007, 18:00–18:15, KIP SR 2.401
Master Integrals for Massless Three-Loop Form Factors — •Tobias Huber1,2, Thomas Gehrmann2, Gudrun Heinrich2,3, Daniel Maitre2, and Cedric Studerus2 — 1Institut f. Theoretische Physik E, RWTH Aachen, D-52056 Aachen — 2Institut f. Theoretische Physik, Universitaet Zuerich, CH - 8057 Zuerich, Schweiz — 3University of Edinburgh, Edinburgh EH9 3JZ, Schottland
The quark and gluon form factors are the simplest objects containing infrared divergencies at higher orders in massless quantum field theory. They are usually computed in dimensional regularization with D=4−2є, where the divergencies appear as poles in є.
At each order in the perturbative expansion, the form factors can be expressed as a linear combination of Master Integrals.
We identify and present all Master Integrals that arise in the computation of the form factors at the three-loop level. We stress some important features such as the presence of bubble insertions or planar vs. crossed topologies.
We then present the results of the computation [1,2] and outline the calculation, with special focus on methods related to hypergeometric functions and Mellin Barnes integrations.
[1] T. Gehrmann, G. Heinrich, T. Huber, C. Studerus, Phys. Lett. B640 (2006) 252. E-Print Archive: hep-ph/0607185
[2] G. Heinrich, T. Huber, D. Maitre, work in progress