The Cheshire Cat Bag Model: Color Anomaly and ${\eta }^{\prime }$ Properties

Abstract

We show that color can leak from a QCD bag if we allow for pseudoscalar isoscalar singlet (${\eta }^{\prime }$) coupling at the surface. To enforce total confinement of color an additional boundary term is suggested. New relations between the ${\eta }^{\prime }$ mass and decay constant and the QCD gluon condensates are derived and compared with the empirical parameters.

Comments: 7 pages, LaTeX, Nordita - 92/68 N