"Integrating in" and Effective Lagrangian for Non-Supersymmetric Yang-Mills Theory

TL;DR

This paper extends a non-supersymmetric effective Lagrangian for Yang-Mills theory by incorporating a heavy fermion, revealing holomorphic dependence on fermion mass and clarifying vacuum structure and theta dependence.

Contribution

It introduces an 'integrating in' approach to include heavy fermions in the effective Lagrangian, linking holomorphy to vacuum structure in non-supersymmetric Yang-Mills theory.

Findings

Holomorphic dependence on heavy fermion mass established

A dimensionless parameter determining vacuum sectors identified

Results compared with Witten's AdS/CFT analysis

Abstract

Recently a non-supersymmetric analog of Veneziano-Yankielowicz (VY) effective Lagrangian has been proposed and applied for the analysis of the theta dependence in pure Yang-Mills theory. This effective Lagrangian is similar in many respects to the VY construction and, in particular, exhibits a kind of low energy holomorphy which is absent in the full YM theory. Here we incorporate a heavy fermion into this effective theory by using the "integrating in" technique. We find that, in terms of this extended theory, holomorphy of the effective Lagrangian for pure YM theory naturally implies a holomorphic dependence on the heavy fermion mass. It is shown that this analysis fixes, under certain assumptions, a dimensionless parameter which enters the effective Lagrangian and determines the number of nondegenerate vacuum sectors in pure YM theory. We also compare our results for the vacuum structure and theta dependence to those obtained recently by Witten on the basis of AdS/CFT correspondence.