相关论文: Variational path-integral approach to back-reactio…
The Nambu-Jona-Lasinio model is supplemented by the quark interaction generated by the one-gluon exchange. The employed gluon propagator exhibits the correct large momentum behavior of QCD, whereas the Landau-pole at low energies is…
Using the Nambu--Jona-Lasinio (NJL) model we study chemical potential response of the pion and kaon masses as a function of temperature and chemical potential, i.e., dm/d\mu (T, \mu). First, we obtain the responses assuming the vector-axial…
We compare two different possibilities to include meson-loop corrections in the Nambu-Jona-Lasinio model: a strict 1/N_c-expansion in next-to-leading order and a non-perturbative scheme corresponding to a one-meson-loop approximation to the…
The effects of meson loops in the vacuum sector of the Nambu--Jona-Lasinio model are calculated. Using the effective action formalism we take consistently all next-to-leading-order $1 \over \Nc$ terms into account. This leads to a…
We derive the effective potentials for composite operators in a Nambu-Jona-Lasinio (NJL) model at zero and finite temperature and show that in each case they are equivalent to the corresponding effective potentials based on an auxiliary…
We investigate the properties of scalar and pseudo-scalar mesons at finite temperature and quark chemical potential in the framework of the Nambu-Jona-Lasinio (NJL) model coupled to the Polyakov loop (PNJL model) with the aim of taking into…
The influence of mesonic fluctuations on quantities in the Nambu-Jona-Lasinio model is examined in different approximation schemes: an expansion in powers of 1/N_c and an expansion up to one-meson loop in the effective action formalism. It…
Path integral techniques in collective fields are shown to be a useful analytical tool to reformulate a field theory defined in terms of microscopic quark (gluon) degrees of freedom as an effective theory of collective boson (meson) fields.…
Radiative decays of pseudoscalar and vector mesons are calculated in the framework of the chiral Nambu-Jona-Lasinio (NJL) model. We use the amplitude for triangle quark loops of anomalous type. In evaluating these loop integrals we use two…
Properties of mesons are investigated within the Nambu--Jona-Lasinio model. We include meson-loop corrections, which are generated via a systematic 1/N_c-expansion in next-to-leading order. We show that our scheme is consistent with chiral…
The charge pion polarizability is calculated in the Nambu-Jona-Lasinio model, where the quark loops (in the mean field approximation) and the meson loops (in the $1/N_c$ approximation) are taken into account. We show that quark loop…
The Bethe--Salpeter equation for pion fluctuations off the chiral soliton in the Nambu--Jona--Lasinio model is constructed. By Goldstone's theorem this equation has rotational and translational zero modes because the classical soliton is a…
We investigate the three flavor Nambu-Jona Lasinio model of neutral quark matter at zero temperature and finite density, keeping into account the scalar, the pseudoscalar and the Kobayashi-Maskawa-'t Hooft interactions as well as the…
In this work, the mass of the neutral pion is investigated in the presence of background magnetic fields in the framework of the Nambu--Jona-Lasinio model. Taking into account the anisotropic four-fermion interactions, a tensor current…
An extended Nambu-Jona-Lasinio (NJL) model with chiral group $U(2)\times U(2)$ and spin-0 and spin-1 four quark interactions is used to develop the gauge covariant approach to the diagonalization of the $\pi-a_1$ mixing in the presence of…
The Nambu--Jona-Lasinio model is the simplest field theory of a composite scalar boson, consisting of a pair of chiral fermions. A bound state emerges from an assumed point-like 4-fermion interaction and is described by local effective…
We investigate the dynamics and mass spectra of charged pseudoscalar ($\pi^+$) and vector ($\rho^+$) mesons in a background magnetic field at finite temperature using the two-flavor Nambu-Jona--Lasinio (NJL) model. By employing a quark…
In the framework of the Nambu--Jona-Lasino (NJL) model, we study the effect of an intense external uniform magnetic field on neutral and charged pion masses and decay form factors. In particular, the treatment of charged pions is carried…
The approach of path integral hadronization, applied to a quark-diquark toy model, is used to derive an effective chiral meson-baryon Lagrangian. In this approach the Goldberger-Treiman relation, found at the quark-meson level, is…
The system of second-order equations of mean-field expansion is considered for Nambu--Jona-Lasinio model with chiral symmetry of SU(2)-group. The system includes equations for four-particle and three-particle functions and also equations…