Dresden 2013 – scientific programme

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T: Fachverband Teilchenphysik

T 23: Quantenfeldtheorie 1

T 23.5: Talk

Tuesday, March 5, 2013, 17:55–18:10, WIL-C129

All-order perturbation theory in non-Abelian gauge theories — •Leila Ali Cavasonza¹ and Giovanni Ridolfi² — ¹Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen, Sommerfeldstr. 16, 52074 Aachen — ²Dipartimento di Fisica, Universita' di Genova and INFN, Via Dodecaneso 33 I16146, Genova Italy

All-order resummation is often crucial to improve fixed-order calculations in perturbative quantum field theories like QCD. Typically one introduces some integral transform, and usually difficulties in computing quantities in the physical space arise, due to non-perturbative effects in the infrared region (the Landau Pole). It is therefore necessary to introduce prescriptions to obtain finite results and, obviously, such prescriptions involve a certain degree of arbitrariness, which leads to uncertainties in the predictions that must be taken under control.

In this project we study some of these prescription and provide physical motivations for their application. More specifically, after an analysis of the so-called traditional resummation procedures (Minimal Prescription and Borel Prescription), we focus on a different approach, which provides resummed quantities free of the problems related to the existence of the Landau Pole. This is done in the analytic infrared coupling hypothesis, using the concept of dispersive integral, and the contribution of the so-called renormalonic diagrams is taken into account. In the perspective of a comparison of this new approach with traditional methods, our analysis focuses on the prescription used to go around the Landau Pole and on the physical justifications for this procedure.