Related papers: Hadron Structure
We briefly review the status of our understanding of hadron structure based on QCD. This includes the role of symmetries, especially chiral symmetry, and the insights provided by lattice QCD. The main focus is on baryon structure and…
This review deals with the structure of hadrons, strongly interacting many-body systems consisting of quarks and gluons. These systems have a size of about 1 fm, which shows up in scattering experiments at low momentum transfers $Q$ in the…
We present an analysis of $\Omega$, $\Xi$, $\Lambda$ and $\phi$ spectra from Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV in terms of distributions of effective constituent quarks at hadronization. Consistency in quark ratios derived from…
Recently there has been considerable interest in the subject of molecules, which are weakly bound states of hadron pairs. The question of the existence of molecules is closely related to the more general problem of the determination of low…
The duality between partonic and hadronic descriptions of physical phenomena is one of the most remarkable features of strong interaction physics. A classic example of this is in electron-nucleon scattering, in which low-energy cross…
To a first semiclassical approximation one can reduce the multi-parton light-front problem in QCD to an effective one-dimensional quantum field theory, which encodes the fundamental conformal symmetry of the classical QCD Lagrangian. This…
I discuss the spectrum of hadrons containing heavy quarks ($b$ or $c$), and how well the experimental results are matched by theoretical ideas. Useful insights come from potential models and applications of Heavy Quark Symmetry and these…
A simple model of hadron which exhibits the quark confinement and the asymptotic freedom is described. The hadron is modelled as a sphere of radius equal to its Compton wavelength in which quarks occur surrounded by space with the uniformly…
Once upon a time, the world was simple: the proton contained three quarks, two {\it ups} and a {\it down}. How these give the proton its mass and its spin seemed obvious. Over the past forty years the proton has become more complicated, and…
The structure of neutrons, protons, and other strongly interacting particles is now being calculated in full, unquenched lattice QCD with quark masses entering the chiral regime. This talk describes selected examples, including the nucleon…
We derive the nucleon non-perturbative sea-quark distributions coming from a composite model involving quarks and hadronic degrees of freedom. The model predicts a definite structured quark-antiquark asymmetry in the nucleon sea.
The Constituent Quark Model has provided a remarkable description of the experimentally observed hadron spectrum but still has no firm theoretical basis. Attempts to provide a QCD justification discussed at Hadron99 include QCD Sum Rules,…
We give an overview of recent progress into the infrared structure of QCD based on the gauge/gravity correspondence and light-front quantization, where the color confining interaction for mesons and baryons is determined by an underlying…
Detailed investigations of the structure of hadrons are essential for understanding how matter is constructed from the quarks and gluons of Quantum chromodynamics (QCD), and amongst the questions posed to modern hadron physics, three stand…
Theoretical and phenomenological studies indicate that the QCD coupling \alpha_s(Q^2) freezes in the infrared. Hadrons may then be described by a perturbative expansion around "Born" states bound only by a confining potential. A linear…
The role of models in Quantum Chromodynamics is to produce simple physical pictures that connect the phenomenological regularities with the underlying structure. The static properties of hadrons have provided experimental input to define a…
We calculate the spin density matrix of the hadron $h$ created via quark fragmentation in the process $e^-e^+ \to q\bar q \to h + X$. In the case of $h=\Lambda$ the experimental data could possibly elucidate the problem of $s$-quark…
The strangeness degrees of freedom in the parton structure of the nucleon are explored in the global analysis framework, using the new CTEQ6.5 implementation of the general mass perturbative QCD formalism of Collins. We systematically…
We show that two dimensional QCD can, to a good approximation, describe the hadronic structure functions measured in Deep Inelastic Scattering. We transform this theory into a new form, Quantum HadronDynamics (QHD), whose semi-classical…
I review recent lattice results on the spectrum and structure of baryons. Limitations due to the quenched approximation and un-physically heavy up and down quarks are discussed, and interfaces between first principles studies of QCD (or…