The 2PPI expansion: dynamical mass generation and vacuum energy

TL;DR

This paper explores the 2PPI expansion method using a 2D model to demonstrate dynamical mass generation and vacuum energy, providing evidence for a gluon condensate and mass in Yang-Mills theory.

Contribution

It introduces the 2PPI expansion as a tool to analyze dynamical mass generation and vacuum energy, with applications to Yang-Mills theory and gluon condensates.

Findings

The 2PPI expansion accurately reproduces known mass gaps in the 2D Gross-Neveu model.

Analytical evidence supports the existence of a <A^2> gluon condensate in Landau gauge.

The condensate leads to a dynamical gluon mass in pure Yang-Mills theory.

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.