Related papers: Glueballs and the Pomeron
We review the determinations of the pseudoscalar glueball and eventual radial excitation of the \eta' masses and decay constants from QCD spectral sum rules (QSSR). The glueball mass is (2.05+-0.19) which one can compare with the eventual…
We study the theta dependence of the spectrum of four-dimensional SU(N) gauge theories, where theta is the coefficient of the topological term in the Lagrangian, for N>=3 and in the large-N limit. We compute the O(theta^2) terms of the…
In pure-glue QCD, gluon-gluon scattering in the $J^{PC}=0^{-+}$ channel is described by a very simple equation, especially if one considers just the leading contribution to the scattering kernel. Of all components in this kernel, only the…
Gauge theories are formulated on the noncommutative two-sphere. These theories have only finite number of degrees of freedom, nevertheless they exhibit both the gauge symmetry and the SU(2) "Poincar\'e" symmetry of the sphere. In…
Using techniques developed in a previous paper three-point functions in field theories described by holographic renormalization group flows are computed. We consider a system of one active scalar and one inert scalar coupled to gravity. For…
We review the recent glueball mass calculations using an efficient method for solving the Schr\"odinger equation order by order with a scheme preserving the continuum limit. The reliability of the method is further supported by new accurate…
We report the progress on the lattice QCD calculation of the glue spin contribution to proton spin. This calculation is carried out with valence overlap fermion on 2+1 flavor DWF gauge configurations at two lattice spacings with the…
The masses of pure gauge glueballs are calculated with the use of relativistic string Hamiltonian without fitting parameters. The string tension $\sigma_f=0.184$~GeV$^2$ in fundamental representation is fixed, using the Necco-Sommer lattice…
Results for the inter-quark potential and low-lying SU(3) glueball spectrum from simulations using a new improved action are presented. The action, suitable for highly anisotropic lattices, contains a two-plaquette term coupling with a…
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…
Using two simple and robust inputs to constrain the mixing matrix of the isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$, we have shown that in the SU(3) symmetry limit, $f_0(1500)$ becomes a pure SU(3) octet and is…
We discuss the existence of glueball states for N=1 SYM within the Maldacena-Nunez model. We find that for this model the existence of an area law in the Wilson loop operator does not imply the existence of a discrete glueball spectrum. We…
In a model with dynamical gluon mass, we investigate the bound states of two and three gluons via a Schr\"odinger equation. The short distance potential is approximated by one-gluon-exchange while the long distance part is assumed to be of…
The mass of the glueballs is calculated in the B.S. equation framework. Under instantaneous approximation, the wave function of B.S. equations are obtained. The kernel is chosen as the sum of an one-gluon exchange potential, a contact…
The pseudo-SU(3) model is extended to explicitly include the spin and proton-neutron degrees of freedom. A general formalism for evaluating matrix elements of one-body and two-body tensor operators within this framework is presented. The…
The present thesis is divided into three parts. In Part I we address a problem within Higher-Spin Gauge Theory in dimension three: namely, that of computing the asymptotic symmetry algebra of supersymmetric models, describing an infinite…
We set up a numerical S-matrix bootstrap problem to rigorously constrain bound state couplings given by the residues of poles in elastic amplitudes. We extract upper bounds on these couplings that follow purely from unitarity, crossing…
Assuming that the Casimir scaling hypothesis is well verified in QCD, masses of glueballs and hybrid gluelumps (gluon with a point-like $c\bar c$ pair) are computed within the rotating string formalism. In our model, two gluons are attached…
We present recent results on the spectrum of a confining flux tube that is closed around a spatial torus as a function of its length as well as the spectrum of glueballs. The extraction of the spectra has been realized by simulating four…
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…