A New Mass Formula for NG Bosons in QCD

Abstract

An often used mass formula for Nambu-Goldstone (NG) bosons in QCD, such as the pions, involves the condensate $<\overline{q}q>$, $f_{\pi }$ and the quark current masses. We argue, within the context of the Global Colour Model to QCD, that this expression is wrong. Analysis of the interplay between the Dyson-Schwinger equation for the constituent quark effect and the Bethe-Salpeter equation for the NG boson results in a new mass formula.

Comments: Minor correction. Extended text incl. appendix