Related papers: Gluons in glueballs: Spin or helicity?
Both positive and negative charge conjugation glueball spectra are computed with a constituent gluon approach. We first compute the spectrum of the Hamiltionian describing two-gluon bound states having $C=+$, before tackling the three-gluon…
We present a model for odd-$C$ (negative charge parity) glueballs with three constituent gluons. The model is an extension of a previous study of two-gluon glueballs. We show that, even if spin-1 gluons seem to reproduce properly the…
Starting from the $0^{++}$ glueball mass and wave function computed from lattice QCD, we compute the local potential between two constituent gluons. Since the properties of constituent gluons are still a matter of research, we allow for…
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…
We propose two approaches for extracting the total gluon helicity contribution to proton spin from lattice QCD, one from local operator matrix elements in a fixed gauge accessible on lattice with feasible renormalization, and the other from…
Glueballs are particles whose valence degrees of freedom are gluons and therefore in their description the gauge field plays a dominant role. We review recent results in the physics of glueballs with the aim set on phenomenology and discuss…
The three-gluon glueball states are studied with the generalization of a semirelativistic potential model giving good results for two-gluon glueballs. The Hamiltonian depends only on 3 parameters fixed on two-gluon glueball spectra: the…
The masses of two-gluon glueballs are studied with a semirelativistic potential model whose interaction is a scalar linear confinement supplemented by a one-gluon exchange mechanism. The gluon is massless but the leading corrections of the…
In the preceding paper, a rigorous three-dimensional relativistic equation for two-gluon bound states was derived from the QCD with massive gluons and represented in the angular momentum representation. In order to apply this equation to…
We discuss states in the meson spectrum which have explicit gluonic components. Glueballs (with no valence quarks) and hybrid mesons (with valence quarks) are both reviewed. We present in some detail lattice simulation results. ( to appear…
Modeling glueballs as bound states of transverse constituent gluons allows to understand the main features of the lattice QCD glueball spectrum. In particular it has been shown in previous works that the lightest C-even glueballs can be…
The scalar glueball, the lightest state in the gluonic Yang-Mills (YM) sector of QCD, is stable in that framework. The scattering of two scalar glueballs is therefore a well defined process in YM, which can be studied with the tools of…
Glueballs are predicted in various theoretical approaches of QCD (most notably lattice QCD), but their experimental verification is still missing. In the low-energy sector some promising candidate for the scalar glueball exist, and some…
We discuss the principles underlying higher spin glueball calculations on the lattice. For that purpose, we develop numerical techniques to rotate Wilson loops by arbitrary angles in lattice gauge theories close to the continuum. As a first…
The total gluon helicity in a polarized proton, measurable in high-energy scattering, is shown to be the large momentum limit of a gauge-invariant but non-local, frame-dependent gluon spin $\vec{E}\times \vec{A}_\perp$ in QCD. This opens a…
Glueballs and other resonances with large gluonic components are predicted as bound states by Quantum Chromodynamics (QCD). The lightest (scalar) glueball is estimated to have a mass in the range from 1 to 2 GeV/c**2; a pseudoscalar and…
We estimate the potential energy for a system of three static gluons in Lattice QCD. This is relevant for the different models of three-body glueballs have been proposed in the literature, either for gluons with a constituent mass, or for…
The status of non-perturbative QCD calculations for mesons with gluonic excitation is presented. Lattice results for the glueball spectrum are reviewed. For hybrid mesons, the heavy quark results are summarised and new results are presented…
A unique feature of quantum chromodynamics (QCD), the theory of strong interactions, is the possibility for gluonic degrees of freedom to participate in the construction of physical hadrons, which are color singlets, in an analogous manner…
We report the first lattice QCD calculation of the glue spin in the nucleon. The lattice calculation is carried out with valence overlap fermions on 2+1 flavor DWF gauge configurations on four lattice spacings and four volumes including an…