Related papers: Structure of the Scalars
The possibility of interpreting baryons containing a single heavy quark as bound states of solitons (that arise in the nonlinear sigma model) and heavy mesons is explored. Particular attention is paid to the parity of the bound states and…
Enormous progress in physics enriched our knowledge about the particles which build matter. Among them there are mesons, to which this thesis is entirely devoted. The overwhelming majority of mesons is made of `conventional' $q\bar{q}$…
In this work, we study the masses of $Qq\bar Q\bar q'$ states with J^{PC}=0^{++}, 1^{++}, 1^{+-} and 2^{++} in the chiral SU(3) quark model, where Q is the heavy quark (c or b) and q (q') is the light quark (u, d or s). According to our…
Heavy meson spectroscopy above open flavor thresholds has become a challenge both from the experimental and theoretical points of view. Experimentally, several signals have been interpreted as meson resonances with unusual properties;…
Despite the apparent simplicity of meson spectroscopy there are some states which cannot be accommodated in the usual $q\bar q$ structure. Among them there are either exotic states as the X(1600) or the recently measured charm states…
The properties of scalar quarks are studied, especially the formation of fermionic mesons with an anti-quark. On the basis of this theoretical investigation together with the experimental data, both from last year and from this year, of the…
A model of scalar gluons and scalar quarks that successfully gives a ln s behavior in high energy qq scattering and which contains a three gluon vertex is used to derive transport equations for the quarks and gluons. Quasiparticle and…
Scalar mesons are a key expression of the infrared regime of QCD. The lightest of these is the $\sigma$. Now that its pole in the complex energy plane has been precisely located, we can ask whether this state is transiently ${\bar q}q$ or…
We present a quark-quark interaction for the complete study of the meson spectra, from the light to the heavy sector. We compare the quark model predictions against well-established $q\bar q$ experimental data. This allows to identify…
By comparing SU(3)-breaking scales of linear mass formulae, it is shown that the lowest vector, axial-vector, and scalar mesons all have a $\bar{q}q$ configuration, while the ground-state octet and decuplet baryons are $qqq$. Also, the…
The interesting state X(1600) with $J^{PC}I^G=2^{++}2^+$ can't be a conventional $q \bar q$ meson in the quark model. Using a mixed interpolating current with different color configurations, we investigate the possible existence of X(1600)…
We first review the work of the Syracuse group, which uses an effective chiral Lagrangian approach, on meson-meson scattering. An illustration providing evidence for the existence of a strange scalar resonance of mass around 900 MeV is…
In this write-up, I summarize the analyses on the low-lying scalar mesons I have done recently with my collaborators. I first briefly review the previous analyses on the hadronic processes related to the scalar mesons, which shows that the…
Quark mass ratios are expressed within the linear meson model by universal relations involving only the masses and decay constants of the flavored pseudoscalars as well as their wave function renormalization. Quantitative results are in…
The relativistic four-quark equations are found in the framework of the dispersion relation technique. The calculations of non-qq meson amplitudes estimate the contributions of three subamplitudes: four-quark amplitude, glueball amplitude…
We conduct a dynamical calculation of pentaquark systems with quark contents $sssu\bar{u}$ in the framework of two quark models: the chiral quark model(ChQM) and quark delocalization color screening model(QDCSM). The effective potentials…
We argue that the experimental decay rates of the f0(1500) meson into two pseudoscalar mesons and into two photons are incompatible with a quark-antiquark state and that the f0(1710) meson is dominantly an ssbar state.
Why do we see certain types of strongly interacting elementary particles and not others? This question was posed over 50 years ago in the context of the quark model. M. Gell-Mann and G. Zweig proposed that the known mesons were $q \bar q$…
In the framework of a nonrelativistic chiral quark model, we continue to study the mass spectra of the fully-heavy $bb\bar{c}\bar{c}$ and $bc\bar{b}\bar{c}$ tetraquarks. In the present calculations, two structures, meson-meson…
Width of molecular-type $Q\bar{Q}q\bar{q}$ hadronic states is discussed. It depends on the quantum numbers of the state and on the details of the long-range mechanism ensuring the bindedness of a molecule. Specific cases when the width is…