The Infrared Behaviour of Quantum Chromodynamics

Citation

Crewther, David Philip (1978) The Infrared Behaviour of Quantum Chromodynamics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/JYNH-9286. https://resolver.caltech.edu/CaltechETD:etd-11102004-095345

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included .pdf document. The infrared properties of scattering matrix elements in Quantum Chromodynamics are studied from the point of view of finding a systematization of perturbation theory that goes beyond the actual order-by-order results. An integro-differential equation for the matrix elements of Quantum Chromodynamics is derived. It is shown (using the ghost-free gauges and an assumption that seems reasonable in those gauges) that all the infrared singularities arising in on mass-shell scattering amplitudes may be collected by a reorganization of the perturbation theory into the iteration of the sum of all insertions of a single gluon between the external states, where the coupling constant at the point of insertion is replaced by the effective coupling constant g(k[superscript 2]) where k is the momentum of the inserted gluon. It is also shown that colour-averaged cross-sections are finite in the infrared limit to all orders of perturbation theory in a fashion that resembles the low order results that have appeared in the literature.

Thesis Files