The 2PPI expansion: dynamical mass generation and vacuum energy

Abstract

We discuss the 2PPI expansion, a summation of the bubble graphs up to all orders, by means of the 2D Gross-Neveu toy model, whose exact mass gap and vacuum energy are known. Then we use the expansion to give analytical evidence that a dimension two gluon condensate exists for pure Yang-Mills in the Landau gauge. This <A^2> condensate consequently gives rise to a dynamical gluon mass.

5 pages. 2 .eps figures. Talk given at the International Conference on Color Confinement and Hadrons in Quantum Chromodynamics, Confinement 2003, TITech and RIKEN, Tokyo, Japan, July 21-24, 2003