Related papers: Scalar mesons and the fragmented glueball
The ratios of partial widths for the decay of a glueball into two pseudoscalar mesons are calculated under the assumption that the production of light quark pairs ($u\bar u,d\bar d,s\bar s$) in soft gluon-\-induced reactions goes on within…
We study the mixing of the scalar glueball into the isosinglet mesons $f_0 (1370)$, $f_0(1500)$, and $f_0(1710)$ to describe the two-body decays to pseudoscalars. We use an effective Hamiltonian and employ the two-angle mixing scheme for…
Ground-state scalar isoscalar mesons and a scalar glueball are described in a U(3)xU(3) chiral quark model of the Nambu--Jona-Lasinio (NJL) type with 't Hooft interaction. The latter interaction produces singlet-octet mixing in the scalar…
Following the re-establishment of the \sigma(600) and the \kappa(900), the light scalar mesons a_0(980) and f_0(980) together with the \sigma(600) and the \kappa(900) are considered as the chiral scalar partner of pseudoscalar nonet in…
This compact review about gluonium focuses on a slate of theoretical efforts; among the many standing works, I have selected several that are meant to assist in the identification, among ordinary mesons, of the few Yang-Mills glueball…
In the light scalar meson sector (M < 1.8 GeV) one expects at least one q qbar nonet and a glueball, possibly also multi-quark states. We discuss the present phenomenological evidence for sigma and kappa particles; if real, they could be…
We have performed a coupled channel study of the meson-meson S-waves involving isospins (I) 0, 1/2 and 3/2 up to 2 GeV. For the first time the channels \pi\pi, K\bar{K}, \eta\eta, \sigma\sigma, \eta\eta', \eta'\eta', \rho\rho, \omega\omega,…
Within a nonlinear chiral Lagrangian framework the correlations between the quark and glueball admixtures of the isosinglet scalar mesons below 2 GeV and the current large uncertainties on the mass of the f0(600) and the f0(1370) are…
The lightest gluonic meson is expected with J^{PC}=0^{++}, calculations in full QCD point towards a mass of around 1 GeV. The interpretation of the scalar meson spectrum is hindered as some states are rather broad. In a largely…
We formulate an extended linear $\sigma$ model of a quarkonia nonet and a tetraquark nonet as well as a complex iso-singlet (glueball) field to study the low-lying scalar meson. Chiral symmetry and $U_A(1)$ symmetry and their breaking play…
Meson properties are considered within a U(3)\times U(3) Linear Sigma Model(LSM). The importance of the U_A(1)-breaking term and the OZI rule violating term in the generation of meson masses and mixing angles is stressed. The LSM parameters…
Scalar and tensor glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU(3) gauge theory. The smallest spatial lattice spacing is about 0.08fm which makes the extrapolation to the continuum limit…
It is commonly believed that the lowest-lying scalar glueball lies somewhere in the isosinglet scalar mesons $f_0(1370), f_0(1500)$ and $f_0(1710)$ denoted generically by $f_{0}$. In this work we consider lattice calculations and…
We discuss the theoretical expectations and phenomenological evidence for the lightest glueballs and the members of the meson nonet with quantum numbers J^PC=0^{++}. We reconsider the recent evidence for candidate states with masses below…
We provide the first explanation of the counter-intuitive scalar glueball couplings to pseudoscalar mesons found in lattice QCD and predict hitherto uncalculated decay modes. Significant a_1 pi and (pi pi)_S (pi pi)_S couplings are found.…
We review the analysis of the quark and gluon substructures of the scalar mesons from QCD spectral sum rules and some low-energy theorems applied to the scalar QCD anomaly current. The present data favour equal components of \bar uu+ \bar…
Within a nonlinear chiral Lagrangian framework, the underlying mixings among quark-antiquark, four-quark and glue components of $f_0(1500)$ and $f_0(1710)$ are studied in a global picture that includes all isosinglet scalar mesons below 2…
We include instanton effects in QCD sum rules for coupled scalar glueballs and mesons. We find a light glueball/sigma as in earlier studies without instantons, but in a lattice-type pure instanton model the light glueball/sigma is not…
In a U(3)x U(3) quark chiral model of the Nambu-Jona-Lasinio type with the 't Hooft interaction, the ground scalar isoscalar mesons and a scalar glueball are described. The glueball (dilaton) is introduced into the effective meson…
The search for the ground state scalar glueball G_0 is reviewed. Spin zero glueballs will have unique dynamical properties if the <G_0|\bar qq> amplitude is suppressed by chiral symmetry, as it is to all orders in perturbation theory: for…