We investigate effects of the vector interaction on chiral and color superconducting (CSC) phase transitions at finite density and temperature in a simple Nambu-JonaLasinio model. It is shown that the repulsive density-density interaction coming from the vector term, which is present in the effective chiral models but has been omitted, enhances the competition between the chiral symmerty breaki...

The question as to what the relevant degrees of freedom are at the thermal chiral phase transition is addressed in terms of the “vector manifestation (VM)” of chiral symmetry à la Harada and Yamawaki. We find that both the vector susceptibility χV and the axial-vector susceptibility χA at the chiral transition require other degrees of freedom than pions in the chiral limit. The possible candida...

We discuss the truncation of low energy effective action of QCD below the chiral symmetry breaking (CSB) scale, including all operators of dimensionality less or equal to 6 which can be built with quark and chiral fields. We perform its bosonization in the scalar, pseudoscalar, vector and axial-vector channels in the large-N c and leading-log approximation. Constraints on the coefficients of th...

The properties of ρ-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 T 2 order, the effective mass is not changed but only the mixing effect in vector and axial-vector correlator appears. PACS numbers : 25.75+r, 11.10.Wx, 11.30.Rd Types...

Chiral symmetry is used as the guiding principle to derive hard thermal loop effects in chiral perturbation theory. This is done by using a chiral invariant background field method for the non-linear sigma model and the WessZumino-Witten lagrangian, with and without external vector and axial vector sources. It is then shown that the n-point hard thermal loop is the leading thermal correction fo...

The recent developments on the “vector manifestation” of chiral symmetry by Harada and Yamawaki provide a compelling evidence for, and “refine,” the in-medium scaling of hadronic properties in dense/hot matter (call it “BR scaling”) proposed by the authors in 1991. We reinterpret the Harada-Yamawaki result obtained in a Wilsonian renormalization-group approach to hidden local symmetry theory ma...

We use heavy vector meson SU~2!L3SU~2!R chiral perturbation theory to predict differential decay distributions for t→rpnt and t→K* pnt in the kinematic region where pV•pp/mV ~here V5r or K*! is much smaller than the chiral symmetry-breaking scale. We also predict the rate for t→vpnt in this region ~now V5v!. Comparing our prediction with experimental data, we determine one of the coupling const...

A general expression of the axial-vector current is presented, in which both the effects of the chiral symmetry breaking and the spontaneous chiral symmetry breaking are included. A new resonance formula of the axial-vector meson is derived and in the limit of q → 0 this formula doesn’t go back to the “chiral limit“. The studies show that the dominance of the axial-vector meson is associated wi...