The infrared behaviour of quantum chromodynamics

broken scale invariance;chiral symmetry;dilation;Goldstone bosons

Crewther, David Philip ; Mann, Murray Gell

University:California Institute of Technology

Department:Physics, Mathematics and Astronomy

关键词: broken scale invariance;    chiral symmetry;    dilation;    Goldstone bosons;   

Others  :  https://thesis.library.caltech.edu/4485/1/Crewther_dp_1978.pdf

美国|英语

来源: Caltech THESIS

【 摘 要 】

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.