Related papers: Ideas in Nonperturbative QCD
Spontaneous breaking of chiral symmetry is investigated in the Hamiltonian approach to QCD in Coulomb gauge. The quark wave functional is determined by the variational principle using an ansatz which goes beyond the commonly used BCS-type…
A basic understanding of the relevant features of hadron properties from first principles QCD has remained elusive, and should be understood as emergent phenomena which depend critically on the number of dimensions of physical spacetime.…
Two crucial properties of QCD, confinement and chiral symmetry breaking, cannot be understood within the context of conventional Feynman perturbation theory. Non-perturbative phenomena enter the theory in a fundamental way at both the…
Through the embedding of superconformal quantum mechanics into AdS space, it is possible to construct an effective supersymmetric QCD light-front Hamiltonian for hadrons, which includes a spin-spin interaction between the hadronic…
We assume that QCD can be effectively described with string-like variables. The hadronic string is built over the chirally non-invariant QCD vacuum by means of the boundary interaction with background chiral fields associated with pions. By…
We review the chiral spin symmetry, which is a symmetry of the color charge and of the confining electric part of QCD. Observation of this symmetry in the vacuum upon truncation of the near-zero modes of the Dirac operator implies that the…
The vacuum is now understood to possess a rich and complex structure, characterized by fluctuating energy fields and a condensate of virtual quark-antiquark pairs. The spontaneous breaking of the approximate chiral symmetry, signaled by the…
We report on the low and moderate Q^2 nucleon spin structure measurements done at Jefferson Lab, examining specifically the inclusive program. We discuss what the data teach us about quark confinement and the emergence of the effective…
Nonperturbative QCD approach is systematically derived starting from the QCD Lagrangian. Treating spin effects as a perturbation, one obtains the universal effective Hamiltonian describing mesons, hybrids and glueballs. Constituent mass of…
In the limit of vanishing up, down and strange quark masses, QCD exhibits a chiral symmetry. This symmetry is broken spontaneously to its vector subgroup, giving rise to Goldstone bosons. These acquire a small mass through the explicit…
We investigate an effective Hamiltonian for QCD at large s, in which longitudinal gauge degrees of freedom are suppressed, but not eliminated. In an axial gauge the effective field theory is a set of coupled (1+1)-dimensional…
We attempt to describe the interplay of confinement and chiral symmetry breaking in QCD by using the string model. We argue that in the quasi-abelian picture of confinement based on the condensation of magnetic monopoles and the dual…
Above the chiral symmetry restoration crossover around T_{ch} ~ 155 MeV a new regime arises in QCD, a stringy fluid, which is characterized by an approximate chiral spin symmetry of the thermal partition function. This symmetry is not a…
Hadron spectra and other properties of quark systems are studied in the framework of a non-relativistic spin-independent phenomenological model. The chosen confining potential is harmonic, which allowed us to obtain analytical solutions for…
The notion induced symmetry breaking (ISB) is introduced as a generalization of the spontaneous symmetry breaking mechanism and is illustrated in a simple two flavor spin model. In the case of QCD at finite baryon density, I argue that the…
In the past year domain wall fermion simulations have moved from exploratory stages to the point where systematic effects can be studied with different gauge couplings, volumes, and lengths in the fifth dimension. Results are presented here…
Quantum Chromodynamics (QCD), the theory of strong interactions, in principle describes the interaction of quark and gluon fields. However, due to the self-coupling of the gluons, quarks and gluons are confined into hadrons and cannot exist…
I introduce and explore a range of topics of contemporary interest in hadronic physics: from what drives the formation of a nonzero quark condensate to the effect that mechanism has on light and heavy meson form factors, and the properties…
The effective quark Lagrangian is written for a light quark in the field of a static antiquark, explicitly containing field correlators as coefficient functions of products of quark operators. At large N_c the closed system of equations for…
Analytic properties of hadronic amplitudes are discussed within the framework of QCD as formulated on the basis of the BRST algebra. Local, composite fields are introduced for hadrons. Given confinement, it is shown that hadronic amplitudes…