Related papers: A note on the Georgi vector limit at finite temper…
We investigate properties of low-energy QCD in a finite spatial volume, but with arbitrary temperature. In the limit of small temperature and small cube size compared to the pion Compton wavelength, Leutwyler has shown that the effective…
The chiral symmetry of QCD is studied at finite temperature and chemical potential using the Schwinger-Dyson equation in the improved ladder approximation. We calculate three order parameters; the vacuum expectation value of the quark…
We reconsider constraints on the eigenvalue density of the Dirac operator in the chiral symmetric phase of 2 flavor QCD at finite temperature. To avoid possible ultra-violet(UV) divergences, we work on a lattice, employing the overlap Dirac…
We analyze chiral restoration within the $O(N+1)/O(N)$ Non-Linear Sigma Model for large $N$ as an effective theory for low-energy QCD at finite temperature $T$. The free energy is constructed diagramatically to ${\cal O}(TM^3)$ in the pion…
We study $D$-dimensional gauge theory with an extra dimension of a circle at finite temperature. We mainly focus on the expectation value of the gauge field for the direction of the extra dimension, which is the order parameter of the gauge…
We review recent results on the role of light quark states within the QCD phase diagram. In particular, we will discuss how the combined use of theoretical techniques such as Effective Theories, Unitarization and Ward Identities helps to…
Restoration of the electroweak symmetry at temperatures around the Higgs mass is linked to tight phenomenological constraints on many baryogenesis scenarios. A potential remedy can be found in mechanisms of electroweak symmetry…
We revisit the question of whether the U_A(1) symmetry is effectively restored in hot and dense medium. In particular, by generalizing the Witten-Veneziano formula to finite temperature, we investigate whether the mass of eta'-meson will…
In the framework of irreversible thermodynamics, we studied the transport properties of QGP. Shear viscosity and non-equilibrium entropy density related to viscous process at finite density has been investigated in weakly coupled limit by…
Quantum chromodynamics with light quarks features an approximate global symmetry, known as chiral symmetry, that is believed to be spontaneously broken by the vacuum expectation value of a scalar and isoscalar composite field, in addition…
In this Chapter we illustrate the close connection between the violation of the weak equivalence principle typical of gravitational interactions at finite temperature, and similar violations induced by a breaking of the local Lorentz…
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 study the symmetry behavior of the Gross-Neveu model in three and two dimensions with random chemical potential. This is equivalent to a four-fermion model with charge conjugation symmetry as well as Z_2 chiral symmetry. At high…
The three-dimensional four-fermion model with a Z_2 chiral symmetry and N=4 fermion species in the system is investigated numerically at non-zero temparature and chemical potential. The phase diagram in the (chemical potential, temperature)…
The effects of the Polyakov loop and of a regularization procedure that allows the presence of high momentum quark states at finite temperature is investigated within the Polyakov-loop extended Nambu--Jona-Lasinio model. The characteristic…
Heat kernel expansions at finite temperature of massless QCD and chiral quark models generate effective actions relevant for both low and high temperature QCD. The key relevance of the Polyakov Loop to maintain the large and…
We analyze the approach to chiral symmetry breaking in QCD at finite temperature, using the functional renormalization group. We compute the running gauge coupling in QCD for all temperatures and scales within a simple truncated…
The constraints imposed by chiral symmetry on hadron correlation functions in nuclear medium are discussed. It is shown that these constraints imply some structure of the in-medium hadron correlators, lead to the cancellation of the order…
Recent topics on mesons in nuclei are discussed by especially emphasizing the role of the partial restoration of chiral symmetry in the nuclear medium. The spontaneously broken chiral symmetry in vacuum is considered to be incompletely…
Assuming that the chiral symmetry of the light degrees of freedom is realized as the vector symmetry proposed by Georgi, we write down a chiral Lagrangian for heavy mesons which incorporates both heavy quark and vector symmetry. Some of the…