Introduction of new coordinates in the description of many-gluon systems (original) (raw)

A new approach to the gluon structure function

We calculate the gluon structure function of a color dipole in a new approach evaluating the matrix elements of SU (2) gluon field operators separated along a direction close to the light cone. As vacuum state in the pure glue sector, we use a variational ground state of the near-light-cone Hamiltonian. With a mean momentum fraction of the gluons fixed to the "experimental value" in a proton, the resulting gluon structure function for a dipole state with four links is compared qualitatively to the NLO MRST 2002 parameterization at Q 2 = 1.5 GeV 2 .

On Quarks and Gluons

This article gives the potential energy function of quark in the gluon field, derives the wave function of quark in stationary state and the quark confinement and asymptotic freedom, shows that a quark is composed of two different color gluons, expounds the formation mechanism of the quark confinement and asymptotic freedom and the physical substance of “colors” of quark, and discusses the stability of hadrons in the end.

A quasiboson approximation for an interacting many-gluon system

Nuclear Physics A, 1987

We develop a quasiboson approximation (QBA) to describe systems containing a large number of gluons. First the method is illustrated in the case of hypothetical gluons, which carry colour {l} and spin-l quantum numbers; subsequently, the method is generalized to include realistic colour {S} and spin-l gluons. We then apply the QBA to glueballs consisting of interacting Ml gluons. The gluon-gluon interaction is determined in second-order perturbation theory based on quantum chromodynamics in a cavity. In the case of a four-gluon system, the QBA leads to almost identical results as the exact calculation, while it becomes exact in the limit of an infinite number of gluons. Using the parameters of the MIT bag model, the energy of the lowest {l}O" state of an even number of gluons decreases quadratically with the number of gluons, thus signalling an instability of the perturbative vacuum against the formation of an Ml gluon condensate.

The glueball spectrum from constituent gluon models

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 lattice QCD spectrum for C = + states, the extension for C = − cannot match with the lattice results. Resorting to the helicity formalism, we show how transverse gluons fit in better agreement the lattice QCD spectrum. We then conclude that even if gluons gain an effective mass, they remain transverse particles.

A Closer Look at Gluons

2021

Gluons are strong interaction gauge fields which interact between quarks, i.e. constituents of baryons and mesons. Interaction of matters is phenomenologically described by gauge theory of strong, electromagnetic, weak and gravitational interactions. In electro-weak theory, left handed leptons lL{l}_LlL and neutrino mathcalnuL{\mathcal \nu}_LmathcalnuL, right handed leptons lR{l}_RlR and left handed quarks uL,dLu_L, d_LuL,dL and right handed quarks uR,dRu_R, d_RuR,dR follow SU(2)timesU(1)SU(2)\times U(1)SU(2)timesU(1) symmetry. Charge of leptons and quarks define hypercharge YYY, and via Higgs mechanism SU(2)LtimesU(1)YSU(2)_L\times U(1)_YSU(2)LtimesU(1)Y symmetry forms U(1)emU(1)_{em}U(1)em symmetry. In order to describe Hadron dynamics properly, embedding of 4-dimensional space to 5-dimensional space was tried in lattice simulations, and in light front holographic QCD (LFHQCD) approach in which conformally symmetric light-front dynamics without ghost are embedded in AdS_5AdS_5AdS_5, and a parameter that fixes a mass scale was chosen from the Principle of Maximum Conformality. Coulomb or Lan...

Towards understanding of confinement of gluons

Nuclear Physics B - Proceedings Supplements, 1997

We report large scale numerical simulation data for gluon propagators together with an analysis based on the generalized Feynman rules of an extended perturbation scheme. Zwanziger's stochastic gauge fixing algorithm is employed to limit the path integration inside the Gribov region. Obtained propagators do not show a simple physical pole behavior, rather complex-conjugate pairs of singularities in the p2 plain.

Vacuum Condensates, Effective Gluon Mass and Color Confinement

2004

We propose a new reformulation of Yang-Mills theory in which three- and four-gluon self-interactions are eliminated at the price of introducing a sufficient number of auxiliary fields. We discuss the validity of this reformulation in the possible applications such as dynamical gluon mass generation, color confinement and glueball mass calculation. We emphasize the transverse-gluon pair condensation as the basic mechanism for dynamical mass generation. The confinement is realized as a consequence of a fact that the auxiliary fields become dynamical in the sense that they acquire the kinetic term due to quantum corrections.

Dynamical gluon mass and linear confinement

arXiv: High Energy Physics - Phenomenology, 2015

We define a non-perturbative running coupling in terms of a gluon mass function, similar to that used in some Dyson-Schwinger approaches. From this coupling, which satisfies asymptotic freedom and describes correctly the singularity structure of confinement, a static quark-antiquark potential is constructed. We calculate the bottomonium and charmonium spectra below the first open flavor meson-meson thresholds and show that for a small range of values of the free parameter determining the gluon mass function a good agreement with data is attained.