Gluon Mass, Glueballs and Gluonic Mesons

TL;DR

This paper reviews evidence and theoretical models for gluon mass generation, the spectrum of glueballs, and their mixing with mesons, providing insights into non-perturbative QCD phenomena and meson structures.

Contribution

It offers a comprehensive review of gluon mass generation, glueball spectrum features, and meson-gluon mixing, including phenomenological implications and effective theories.

Findings

Evidence supports dynamical gluon mass generation.

Glueball spectrum features are characterized in pure gauge theories.

Mixing between glueballs and mesons affects scalar and pseudoscalar meson properties.

Abstract

We review the phenomenological and theoretical evidences for dynamical gluon mass generation and the main features of the glueball spectrum in (pure gauge) Yang-Mills theories. The mixing between glueball and conventional $\bar q q$ states in $f_0$ scalar mesons is discussed. For pseudoscalar mesons, the inclusion of the glue field in an effective low energy theory is presented leading to a third isoscalar $\eta''$ partner of the $\eta$ and $\eta'$. Branching ratios for processes involving $\eta''$ are given and, when available, compatible with data for $\eta(1405)$.