相关论文: A renewed look at eta' in medium
Chiral symmetry restoration at nonzero temperature is studied in the framework of the O(4) linear sigma model and the U(N_f)_r x U(N_f)_l linear sigma model with N_f=2,3, and 4 quark flavors. We investigate the temperature dependence of the…
We investigate the finite temperature behavior of the meson sector of an effective Lagrangian which describes nuclear matter. A method is developed for evaluating the logarithmic terms in the effective potential which involves expansion and…
Some topics are introduced on possible evidences of chiral restoration in nuclei and related ones. The topics include the $\sigma$-mesonic mode in nuclei, the vector mesons in a nuclear matter, deeply bound pionic and Kaonic nuclei with a…
Phase transitions in hot and dense matter and the in--medium behavior of pseudoscalar mesons ($\pi^{\pm}, \pi^0, K^{\pm}, K^0 ,\bar K^0,\eta {and} \eta' $) are investigated, in the framework of the three flavor Nambu--Jona-Lasinio model,…
This paper is organized in two parts. The first part (Sections 2-5) is dedicated to the theory at T=0 and contains a pedagogical review of some fundamental aspects related with the chiral symmetries of QCD, the U(1) problem and its solution…
We study the spectroscopy and transport properties of charmed mesons in a thermal medium by applying an effective field theory based on chiral and heavy-quark symmetries in the imaginary time formalism. Relying on unitarity constraints and…
The properties of $\rho$-mesons at finite temperature ($T$) are examined with an effective chiral lagrangian in which vector and axial-vector mesons are included as massive Yang-Mills fields of the chiral symmetry. It is shown that, at…
We investigate the axial $U(1)$ symmetry restoration at finite temperature in two flavor QCD. We employ the M\"obius domain-wall formalism that is designed to achieve good chiral symmetry. We show the measurements of a difference of meson…
The singlet pseudoscalar sector of light mesons is investigated in the soft-wall model, a bottom-up approach to the AdS/QCD correspondence. The $\eta^\prime$ mass results from the mixing among the fields dual to the axial current,…
In this article we study restoration of chiral symmetry at finite temperature for quark matter with a chiral chemical potential, $\mu_5$, by means of a quark-meson model with vacuum fluctuations included. Vacuum fluctuations give a…
The radiative decays of the pseudoscalar mesons $P=(\pi^0,\eta,\eta')$ are of special interest as they provide an experimental window on the electromagnetic and colour chiral $U_A(1)$ anomalies. $\pi^0\to\gamma\gamma$ is well described by…
We study the non restoration of symmetries with a local order parameter in field theory at finite temperature. After giving an interpretation of the phenomenon, we show that hierarchy problems are a necessary condition for its realization…
Simple group-theoretical arguments are used to demonstrated that in the high temperature (chirally restored) phase of QCD with N massless flavours, all n-point correlation functions of quark bilinears are invariant under U(1) axial…
The fate of symmetries at high temperature determines the dynamics of the very early universe. It is conceivable that temperature effects favor symmetry breaking instead of restoration. Concerning global symmetries, the non-linear sigma…
We propose that the mass of the $\eta^\prime$ meson is a particularly sensitive probe of the properties of finite energy density hadronic matter and quark gluon plasma. We argue that the mass of the $\eta^\prime$ excitation in hot and dense…
The axion is one of the more interesting candidates to make the dark matter of the universe, and the axion potential plays a fundamental role in the determination of the dynamics of the axion field. Moreover, the way in which the $U(1)_A$…
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…
An expansion in the number of spatial covariant derivatives is carried out to compute the $\zeta$-function regularized effective action of 2+1-dimensional fermions at finite temperature in an arbitrary non-Abelian background. The real and…
Two closely related topological phenomena are studied at finite density and temperature. These are chiral anomaly and Chern--Simons term. It occurs that the chiral anomaly doesn't depend on density and temperature. Chern-Simons term…
QCD sum rules serve as tools to investigate changing hadronic properties in a hot and/or dense nuclear medium. The role of chiral symmetry breaking and restoration effects in a medium can be addressed also in the heavy-light meson sector.…