Quenched glueball spectrum from functional equations

TL;DR

This paper computes the quenched glueball spectrum using self-consistent two-body bound state equations derived from the 3PI effective action, showing good agreement with lattice results and presenting new two-loop calculations for pseudoscalar glueballs.

Contribution

It introduces a parameter-free, self-contained method for calculating the glueball spectrum using the 3PI effective action and provides the first two-loop results for pseudoscalar glueballs.

Findings

Results agree with lattice data for several quantum numbers.

First two-loop calculation for pseudoscalar glueball spectrum.

Method is fully self-consistent and parameter-free except for the coupling.

Abstract

We give an overview of results for the quenched glueball spectrum from two-body bound state equations based on the 3PI effective action. The setup, which uses self-consistently calculated two- and three-point functions as input, is completely self-contained and does not have any free parameters except for the coupling. The results for $J^{\mathsf{PC}}=0^{\pm+},2^{\pm+},3^{\pm+},4^{\pm+}$ are in good agreement with recent lattice results where available. For the pseudoscalar glueball, we present first results from a two-loop complete calculation, rendering also the bound state calculation fully self-consistent.