Related papers: Experimental Challenges for QCD - The past and the…
We study the five-quark system composed of $qqs\bar{Q}Q$ configuration ($q = u$ or $d$, $Q=b$ or $c$), in the framework of the chiral quark model. In consequence, a series of bound states with heavy flavors are predicted by precise…
The first-principle approach to the dense state of QCD matter, i.e. the lattice-QCD simulation at finite baryon density, is not under theoretical control for the moment. The effective model study based on QCD symmetries is a practical…
The hadronic spectrum obtained in the framework of a QCD-inspired schematic model, is presented. The model is the extension of a previous version, whose basic degrees of freedom are constituent quarks and antiquarks, and gluons. The…
The Global Colour Model (GCM) of QCD is a quark-gluon quantum field theory that very successfully models QCD for low energy hadronic processes. An effective gluon correlator models the interaction between quark currents. Functional integral…
We study two effective models for QCD, the Nambu-Jona-Lasinio -model and the linear sigma model extended by including a Polyakov loop potential, which is fitted to reproduce pure gauge theory thermodynamics, and a coupling between the…
When hadrons scatter at high energies, strong color fields, whose dynamics is described by quantum chromodynamics (QCD), are generated at the interaction point. If one represents these fields in terms of partons (quarks and gluons), the…
Recent findings on the spectrum of heavy-quark mesons from computer simulations of quarks and gluons in lattice QCD are summarized, with particular attention to quark-antiquark states bound by an excited gluon field. The validity of a…
The propagation of colored quarks through strongly interacting systems, and their subsequent evolution into color-singlet hadrons, are phenomena that showcase unique facets of Quantum Chromodynamics (QCD). Medium-stimulated gluon…
We report on a study of QCD thermodynamics with three flavors of quarks, using a Symanzik improved gauge action and the Asqtad O(a^2) improved staggered quark action. Simulations were carried out with lattice spacings 1/4T, 1/6T and 1/8T…
The functional integral for QCD is reformulated by introducing explicitly an integration over the fluctuations of composite quark-antiquark bound states. Chiral symmetry breaking by the color singlet scalar field induces masses for the…
'Constituent quarks' means massive quarks, in contrast to the nearly massless u,d,s quarks of the QCD lagrangian. The dynamical or constituent masses appear owing to the spontaneous chiral symmetry breaking in QCD. A realistic mechanism of…
In the first part I briefly survey recent issues in constituent quark models raised by the observation of unusual hadronic states. In particular I discuss the role of higher Fock components in the wave function of baryons and the possible…
We explore further the idea that the lattice QCD data for hadron properties in the region m_\pi^2 > 0.2 GeV^2 can be described by the constituent quark model. This leads to a natural explanation of the fact that nucleon excited states are…
When quarks and gluons are led to form a dense medium, like in high energy or/and heavy-ion collisions, it is interesting to ask the question which are the relevant degrees of freedom that Quantum Chromodynamics predict. The present notes…
The dynamical scenario is considered for N=1 SQCD, with N_c colors and N_c<N_F<3N_c flavors with small but nonzero current quark masses m_Q\neq 0, in which quarks form the diquark-condensate phase. This means that colorless chiral quark…
N=1 SQCD with SU(N_c) colors and N_F flavors of light quarks is considered within the dynamical scenario which assumes that quarks can be in two different phases only. These are: a) either the HQ (heavy quark) phase where they are confined,…
We identify a "$\Lambda$ selection rule" for $N^*$ resonances in the presence of QCD mixing effects. We quantify these mixing effects from existing data and predict amplitudes for exciting {\bf 20} representations in SU(6), which are…
We study the transitions between the different color states of a static quark-antiquark pair, singlet and octet, in a thermal medium. This is done non-perturbatively exploiting the infinite mass limit of QCD. This study is interesting…
We propose a qualitatively new mechanism for quarkonium production, motivated by the global features of the experimental data and by the successes/failures of existing models. In QCD, heavy quarks are created in conjunction with a…
The 1/N_c expansion (N_c being the number of QCD colors) has been applied in recent papers to the phenomenology of excited baryon resonances. This talk surveys the work done to date, and discusses its successes and remaining challenges.