Related papers: Relativistic theory of string breaking in QCD
The phase diagram of massless quantum electrodynamics in three space-time dimensions as a function of fermion flavor number $N$ exhibits two well-known phases: at large $N > N_c^{conf}$ the system is in a conformal gapless state, while for…
Considered are ${\cal N}=2\, SU(N_c)$ or $U(N_c)$ SQCD with $N_F<2N_c-1$ quark flavors with the quark mass term $m{\rm Tr}\,({\bar Q} Q)$ in the superpotential. ${\cal N}=2$ supersymmetry is softly broken down to ${\cal N}=1$ by the mass…
In this review paper the QCD vacuum properties and the structure of color fields in hadrons are studied using the complete set of gauge-invariant correlators of gluon fields. Confinement in QCD is produced by the correlators of some certain…
New results on baryon structure and spectrum developed in collaboration with Dan Riska [1-4] are reported. The main idea is that beyond the chiral symmetry spontaneous breaking scale light and strange baryons should be considered as systems…
On a null-plane (light-front), all effects of spontaneous chiral symmetry breaking are contained in the three Hamiltonians (dynamical Poincar\'e generators), while the vacuum state is a chiral invariant. This property is used to give a…
We study the scalar and pseudoscalar sector in a five-dimenional model describing chiral symmetry breaking. We calculate the scalar and pseudoscalar two-point correlator, the mass spectrum and interactions. We also obtain the scalar and…
Spontaneous violation of relativistic invariance of the vacuum can derive quantum chromodynamics from an U(1) Higgs model including fermions, if the emergent theory is Lorentz invariant. In this model, the vacuum becomes anisotropic, and a…
We present results of our ongoing determination of string breaking in full QCD with N_f=2 Wilson fermions. Our investigation of the fission of the static quark-antiquark string into a static-light meson-antimeson system is based on…
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…
Due to its light mass of order Lambda_QCD, the strange quark can play a special role in Chiral Symmetry Breaking (ChSB): differences in the pattern of ChSB in the limits N_f=2 (m_u,m_d->0, m_s physical) and N_f=3 (m_u,m_d,m_s->0) may arise…
I review various aspects of chiral symmetry and its spontaneous breaking on null planes, including the interesting manner in which Goldstone's theorem is realized and the constraints that chiral symmetry imposes on the null-plane…
We propose a novel lattice calculation of spontaneous chiral symmetry breaking in QED model with 2+1 dimensional fermion brane. Considering the relativistic action with gauge symmetry we rigorously carry out path integral in Monte-Carlo…
A new set of boundary conditions for string propagators is proposed in this paper. The boundary conditions are parametrized by a complex number $\lambda$. Under these new boundary conditions, the left-moving and right-moving modes are…
Using the gauge/string duality, we model a heavy quark-antiquark pair in a color singlet state moving through a cold medium and explore the consequences of temperature and velocity on string breaking. We show that the string breaking…
Based on the AdS/CFT correspondence we study the breaking of the chiral symmetry in QCD using a simple five dimensional model. The model gives definite predictions for the spectrum of vector mesons, their decay constants and interactions as…
The light quark propagation in the confining vacuum, described by an (infinite) set of gauge-invariant vacuum correlators, is studied in detail. To keep gauge invariance at each step the system of light quark and heavy antiquark is…
We study the changes in the short-distance quark structure of the Nambu-Goldstone boson when the long-distance symmetry-breaking scales are depleted controllably. We achieve this by studying the valence Parton Distribution Function (PDF) of…
A model for the QCD vacuum based on domain-like background gluon fields has previously been developed and demonstrated to exhibit confinement of quarks and strong correlation of the local chirality of quark modes and duality of the…
We investigate the spontaneous symmetry breaking in a nonlocal version of the scalar QED. When the mass parameter $m^2$ satisfies the requirement $m^2>0$, we find that all fields, including the Nambu-Goldstone field, acquire a non-zero mass…
Dynamical chiral symmetry breaking is a nonperturbative phenomenon that may be studied using QCD's gap equation. Model-independent results can be obtained with a nonperturbative and symmetry preserving truncation. The gap equation yields…