Related papers: Role of axial-vector mesons near the chiral phase …
The $U(1)_A$ symmetry of the massless QCD Lagrangian is explicitly broken by the axial anomaly, but it may be effectively restored at finite temperature. Determining the temperature at which this occurs is important for understanding the…
The behavior of the vector Adler function at spacelike momenta is studied in the framework of a covariant chiral quark model with instanton-like quark-quark interaction. This function describes the transition between the high energy…
The renormalized contribution of fermions to the curvature masses of vector and axial-vector mesons is derived with two different methods at leading order in the loop expansion applied to the (2+1)-flavor constituent quark-meson model. The…
Theoretical approaches to assess modifications of vector mesons in the medium, as well as their experimental identification via electromagnetic probes, are discussed. Implications for the nature of chiral symmetry restoration in hot/dense…
The recent suggestion of a vanishing flavor-singlet axial charge of nucleon due to a nontrivial vacuum structure is further amplified. A perturbative QCD discussion, applicable for the heavy quark contributions, relates it to the physics of…
Corrections to $K\rightarrow\pi\pi\pi$ induced by vector and scalar meson exchange are investigated within chiral perturbation theory.
A simple model for the instanton ensemble at finite temperature T is proposed, including ``random" and strongly correlated ``molecular" component. T-dependence of fermionic zero modes naturally leads to chiral symmetry restoration, without…
We investigate the restoration patterns of chiral and $U(1)$ axial symmetries at finite temperature using a soft-wall holographic QCD model. The study employs two distinct parameter sets (Case I and Case II), both calibrated to reproduce a…
The extracted value for the $g^{eff}_{\omega \rho\pi}$ effective coupling from experimental data, considering only the $\rho$ meson, resumes not only the $\rho$ meson effect but also all its additional radial excitation modes. By explicitly…
Statistical average of the axial current is evaluated on the basis of the covariant Wigner function. In the resulting formula, chemical potential $\mu$, angular velocity $\Omega$ and acceleration $a$ enter in combination $\mu \pm (\Omega…
We consider the light-quark axial-vector current correlator in the framework of thermal QCD sum rules to: (a) find a relation between chiral-symmetry restoration and deconfinement, and (b) determine the temperature behaviour of the…
Vacuum and thermal properties of pseudoscalar and vector charm mesons are analyzed within a self-consistent many-body approach, employing a chiral effective field theory that incorporates heavy-quark spin symmetry. Upon unitarization of the…
We evaluate equal time point to point spatial correlation functions of mesonic currents at finite temperature. For this purpose we consider the QCD vacuum structure in terms of quark antiquark condensates and their fluctuations in terms of…
The temperature behaviour of meson condensates $<\sigma_0>$ and $<\sigma_8>$ is calculated in the $SU(3)\times SU(3)$-linear sigma model. The couplings of the Lagrangian are fitted to the physical $\pi,K,\eta,\eta'$ masses, the pion decay…
The response of chiral fermions to time and space dependent axial imbalance & constant magnetic field is analyzed. The axialvector-vector-vector (AVV) three-point function is studied using a real-time approach at finite temperature in the…
We study the thermal transition of QCD with two degenerate light flavours by lattice simulations using $O(a)$-improved Wilson quarks. Temperature scans are performed at a fixed value of $N_t = (aT)^{-1}=16$, where $a$ is the lattice spacing…
Based on schematic two-level models extended to $a_1$-meson degrees of freedom, we investigate possible mechanisms of chiral restoration in the vector/axialvector channels in cold nuclear matter. In the first part of this article we employ…
Based on the hidden local symmetry (HLS) Lagrangian as an effective field theory of QCD, we find that the chiral symmetry restoration for hot QCD can be realized through the Vector Manifestation where the rho meson becomes massless…
Recent developments in the evaluation of vector-meson spectral functions in hot and dense matter are discussed with emphasis on connections to the chiral phase transition in QCD. Model independent approaches including chiral low-density…
We propose ``vector manifestation (VM)'' of the Wigner realization of the chiral symmetry in which the symmetry is restored at the critical point by the massless degenerate pion (and its flavor partners) and rho meson (and its flavor…