Related papers: The light scalar mesons within quark models
Attention is paid to the production mechanisms of light scalars that reveal their nature. We reveal the chiral shielding of the \sigma(600) meson. We show that the kaon loop mechanism of the \phi radiative decays, ratified by experiment,…
The following topics are considered. 1. Confinement, chiral dynamics and light scalar mesons. 2. $\phi$-meson radiative decays about nature of light scalar resonances. Arguments in favor of the four-quark model of the $a_0(980)$ and…
Using ideas underlying the flavour-blind "Nijmegen Unitarised Meson Model" we try to understand on the basis of a system of Schroedinger equations with one meson-meson and one (spinless) quark-antiquark channel coupled by a simple…
Using effective field theory methods, we discuss the extraction of the mass and width of the scalar mesons f0(980) and a0(980) from the finite-volume spectrum in lattice QCD. In particular, it is argued that the nature of these states can…
The high-statistical KLOE data on the $\phi\to\pi^0\pi^0\gamma$ decay are described simultaneously with the data on $\pi\pi$ scattering and the $\pi\pi\to K\bar K$ reaction. The description is carried out taking into account the chiral…
I review the lattice simulations of light scalar mesons with quark-antiquark and tetraquark interpolating fields. Several difficulties which complicate the extraction of scalar meson masses from the scalar correlators are pointed out. One…
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…
The analysis of the poles of the $\pi\pi$ scattering amplitude is shown to favour a dynamical origin of the sigma meson: it is created by a strongly attractive $\pi\pi$ interaction in the $J^{PC}=0^{++}I=0$ channel. In the limit…
A classification of the $IJ^{PC}=00^{++}$ mesons is performed on the basis of the K-matrix analysis of meson spectra in the reactions: (i) GAMS data on $\pi p\to \pi^0\pi^0 n$, $\eta\eta n$, $\eta\eta' n$; (ii) Crystal Barrel data on $p\bar…
Resonances appearing in hadronic scattering processes are described by a two-phase model. In the one phase, scattering products are observed, whereas the other phase describes confinement. A so-called ``Resonance-Spectrum Expansion'' is…
We calculate low-energy meson decay processes and pion-pion scattering lengths in a globally chirally invariant two-flavour linear sigma model exploring the quark content of the scalar mesons f(0)(600) and a(0)(980), as well as f(0)(1370)…
The light-quark non-strange scalar mesons a0(980), f0(980), f0(1370), a0(1450), f0(1500) and f0(1710) are of great interest as there is no generally accepted view of their structure which can encompass q-q-qbar-qbar, molecular, q-qbar and…
The available data on the a0(980), f0(980), f0(1300) and K*0(1430) mesons are fitted as a distorted 0++ nonet using only 6 parameters and a very general model. This includes all light two-pseudoscalar thresholds, constraints from Adler…
We report on our recent progress in the generation of resonant behavior in unitarized meson-meson scattering amplitudes obtained from Chiral Perturbation Theory. These amplitudes provide simultaneously a remarkable description of the…
Properties of scalar--isoscalar mesons in a mass range from pi-pi threshold up to 1800 MeV are analysed using an unitary model with separable interactions in three decay channels: pi-pi, K-anti K and an effective 2pi-2pi. Different…
Spectrum of masses of light pseudoscalar ($\pi, K, \eta, \eta'$) and vector ($\rho, K^*, \omega, \phi$) mesons can be explained on the base of the following assumptions: (1) analytical confinement (propagators of quarks and gluons are…
The three flavor linear sigma model is studied as a ``toy model'' for understanding the role of possible light scalar mesons in the \pi \pi, \pi K and \pi \eta scattering channels. The approach involves computing the tree level partial wave…
We have performed a systematical calculation of the pion ($\pi, K, \eta$) and heavy pseudoscalar meson S-wave scattering lengths up to ${\cal O}(p^3)$ in the chiral perturbation theory in the heavy quark symmetry limit. With the three…
We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite…
Pole trajectories connecting light and heavy scalar mesons, both broad resonances and quasi-bound states, are computed employing a simple coupled-channel model. Instead of varying the coupling constant as in previous work, quark and meson…