相关论文: Glue Condensate, Quark Condensate and Dirac Spectr…
Quark and gluon scalar densities, $\langle \bar{\psi} \psi \rangle$ and $\langle F^2 \rangle$, reflect the degree of scale-invariance violations in SU(N) gauge theories with fundamental quarks. It is known that $\langle \bar{\psi} \psi…
Using the quark-meson coupling (QMC) model, we study the density dependence of the quark and gluon condensates in nuclear matter. We show that the change of the quark condensate is mainly driven by the scalar field in the medium and that…
We present a new perspective on the nature of quark and gluon condensates in quantum chromodynamics. We suggest that the spatial support of QCD condensates is restricted to the interiors of hadrons, since these condensates arise due to the…
We propose to calculate the gluon condensate in lattice QCD in an indirect way by extracting it from the correlator of hadronic currents of heavy quarks. Moments (derivatives with respect to momentum at vanishing momentum) of the vector and…
We derive here the equation of state for quark matter with a nontrivial vacuum structure in QCD at finite temperature and baryon density. Using thermofield dynamics, the parameters of thermal vacuum and the gluon condensate function are…
A new relation between $\rho$-meson mass, weak $\pi$-meson decay constant, quark and gluon condensates is derived from the QCD sum rules. As a byproduct an explanation for the dominance of $\rho\rho$-decay for the $f_0(1370)$-meson is…
A continuum expression for the trace of the massive dressed-quark propagator is used to explicate a connection between the infrared limit of the QCD Dirac operator's spectrum and the quark condensate appearing in the operator product…
The bounds on the values of gluon, four-quark and quark-gluon condensates are derived from the requirement of consistency of the sum rules for various correlators of the hybrid current $a_{\mu}=g\bar d\gamma_{\rho}\tilde G_{\rho\mu}u$. The…
We exhibit the method for obtaining non perturbative quark and gluonic vacuum condensates from a model truncation of QCD. The truncation allows for a phenomenological description of the quark-quark interaction in a framework which maintains…
We investigate a connection between a renormalon ambiguity of heavy quark mass and the gluon condensate contribution into the quark dispersion law related with a virtuality defining a displacement of the heavy quark from the perturbative…
The mixed quark-gluon condensate is another chiral order parameter in QCD, which plays an important role in the application of QCD sum rules. In this letter, we study the properties of quark-gluon mixed condensate at finite temperature and…
The early idea that a non-perturbative gluon condensate affects the spectrum of heavy quarks is revisited in the light of modern simulation techniques. We evaluate the low lying spectrum of bound states of two heavy quarks for large…
It is known now that chiral symmetry restoration requires the meson-nucleon coupling to be density dependent in nuclear-matter mean-field models. We further show that quite generally, the quark and gluon condensates in medium are related to…
We begin with the discussion of the relationship between the trace of the energy momentum tensor and the gluon condensate at finite temperatures. Using the recent numerical data from the simulations of lattice gauge theory for quantum…
We investigate the thermal behaviour of gluon and chiral condensates within an effective Lagrangian of pseudoscalar mesons coupled to a scalar glueball. This Lagrangian mimics the scale and chiral symmetries of QCD. (Submitted to Z. Phys.…
The gluon and quark condensates and their temperature dependence are investigated within QCD premises. The input for the former is a gauge invariant $gg$ kernel made up of the direct (D), exchange (X) and contact(C) QCD interactions in the…
The in-medium behavior of the nucleon spectral density including self-energies is revisited within the framework of QCD sum rules. Special emphasis is given to the density dependence of four-quark condensates. A complete catalog of…
One-loop quark contributions to the dimension-four gluon condensate term in the operator product expansion (OPE) of the scalar glueball correlation function are calculated in the MS-bar scheme in the chiral limit of $n_f$ quark flavours.…
The low-energy QCD theorems are generalized in the presence of a constant magnetic field H. Two-loop approximation for the vacuum energy density in the framework of the chiral perturbation theory was obtained and the quark and gluon…
Our renormalization group consistent variant of optimized perturbation, RGOPT, is used to calculate the nonperturbative QCD spectral density of the Dirac operator and the related chiral quark condensate $\langle \bar q q \rangle$, for…