Constituent gluon interpretation of glueballs and gluelumps

Abstract

Arguments are given that support the interpretation of the lattice QCD glueball and gluelump spectra in terms of bound states of massless constituent gluons with helicity-1. In this scheme, the mass hierarchy of the currently known gluelumps and glueballs is mainly due to the number of constituent gluons and can be understood within a simple flux tube model. It is also argued that the lattice QCD 0 +− glueball should be seen as a four-gluon bound state.

The structure of the Yang–Mills spectrum for arbitrary simple gauge algebras

“…The spin-space part could also depend on the gauge algebra through a change in the numerical values of the parameters appearing in a specific Hamiltonian, but this would only affect quantitatively the mass spectrum, not the basic properties studied in this work like the allowed quantum numbers and the mass hierarchy. As stressed in [11], those global properties are mostly consequences of the colour structure of a given state -responsible for C according to (2) -and of the peculiar dynamics induced by the transversality of the quasigluons and the Pauli principle -responsible for J P .…”

“…Although the explicit form of (anti)symmetrized threequasigluon states within Wick's three-body helicity formalism [38] will not be given here for the sake of clarity, some observations can be made concerning the quantum numbers of the lightest three-quasigluon states. Group-theoretical arguments developed in [11] show that the lowest-lying three-quasigluon glueballs will have the quantum numbers 0 −+ and (1, 3) +− . The absence of low-lying 0 P − state is in agreement with [39], that is actually an extension of Yang's theorem to three-photon states, showing that no (pseudo)scalar three-photon state may exist.…”

“…Such a framework has proved to give an accurate and intuitive description of the lattice data in the su(3) case, see e.g. the review [13], or more specifically [11,12]. A quasigluon approach is actually the framework in which the gauge-algebra dependence of the observables appears the most clearly and can be the most straightforwardly dealt with.…”

The glueball spectrum from constituent gluon model

“…This work is in progress. However, we have some indications that the lowest-lying odd-C glueballs with transverse gluons are spin 1 and 3 [13]. Symmetry arguments are also in favour of a four-gluon interpretation for 0 +− .…”

Constituent Gluons in Hybrid Mesons: A Group Theoretical Analysis

“…Table 2: Possible number of constituent gluons corresponding to the number of hybrid mesons upto multiplicityThe predictions discussed above do not give any information about the relationship between the number of constituent gluons and the masses of the observed hybrids since in exact SU (3) C symmetry, gluons are massless. However, there are specific models in literature, where the constituent gluons have effective mass of the order of 0.7 GeV [16,17] resulting in the following degenerate mass relation:…”