Some Aspects of the U(1) Problem and the Pseudoscalar Mass Spectrum

Abstract

A complete discussion of the nonet pseudoscalar mass spectrum and related topics is given. The U(l) problern is briefly reviewed and the large-N point of view is considered. The necessity for a vector ghost gluonic particle, in order to resolve the U(l) problem, is stressed. Scalar ghosts and the Kogut-Susskind mechanism are shown to be insufficient. An analysis of the 1]-1]' mixing problem, with and without PCAC corrections, is made and it is suggested that the singlet decay constant may be nearly twice as large as the other octet decay constants. A general discussion of PCAC corrections is given and the remaining pseudoscalars are considered. As byproducts quark mass values are given and the rnq dependence of

https://doi.org/10.1071/PH840241

© CSIRO 1984