A search for non-qqbar mesons at the CERN Omega Spectrometer

TL;DR

This paper reports on a search for non-qqbar mesons, such as glueballs and hybrids, at CERN, finding candidates that are enhanced at small transverse momentum differences, supporting their non-quark-antiquark nature.

Contribution

It provides experimental evidence for non-qqbar mesons and analyzes their production dependence on transverse momentum differences, highlighting potential glueball candidates.

Findings

Non-qqbar candidates observed in central production.

Glueball candidates are enhanced at small dPT.

qqbar mesons are suppressed at small dPT.

Abstract

The non-Abelian nature of QCD suggests that particles that have a gluon constituent, such as glueballs or hybrids, should exist. Experiments WA76, WA91 and WA102 have performed a dedicated search for these states in central production using the CERN Omega Spectrometer. Several non-qqbar candidates have been observed. This paper presents a study of central meson production as a function of the difference in transverse momentum (dPT) of the exchanged particles which shows that undisputed qqbar mesons are suppressed at small dPT whereas the glueball candidates are enhanced.