Related papers: Two regularizations - two different models of Namb…
We present a derivation of the low-energy effective meson Lagrangian of the extended Nambu -- Jona-Lasinio (ENJL) model. The case with linear realization of broken $SU(2)\times SU(2)$ chiral symmetry is considered. There are two crucial…
The chiral phase transition is studied in an extended Nambu--Jona-Lasinio model with eight-quark interactions. Equations for scalar and vector quark densities, derived in the mean field approximation, are nonlinear and mutually coupled. The…
Catalysis of dynamical symmetry breaking by a constant magnetic field in (3+1) dimensions is considered. We use the three flavour Nambu -- Jona-Lasinio type model with 't Hooft and eight-quark interaction terms. It is shown that the…
An investigation of the Nambu-Jona-Lasino model with external constant electric and weak gravitational fields is carried out in three- and four- dimensional spacetimes. The effective potential of the composite bifermionic fields is…
It is recently shown that in 4D $SU(N)$ Nambu--Jona-Lasinio (NJL) type models, the $SU(N)$ symmetry breaking into its special subgroups is not special but much more common than that into the regular subgroups, where the fermions belong to…
Two-parton correlations in the pion, a non perturbative information encoded in double parton distribution functions, are investigated in the Nambu and Jona-Lasinio model. It is found that double parton distribution functions expose novel…
We investigate the renormalization group flow of the Yukawa model with a fixed momentum cutoff at the leading order in 1/N, where N is the number of the fermion species. We demonstrate the scale invariance of coupling constants of the…
We discuss inhomogeneous ground states of the Nambu-Jona-Lasino (NJL) and quark-meson (QM) model within mean-field approximation and their possible existence in the respective phase diagrams. For this purpose we focus on lower dimensional…
In the leading order of a modified 1/Nc expansion, we show that a class of gauge-Higgs-Yukawa systems in four dimensions give non-trivial and well-defined theories in the continuum limit. The renormalized Yukawa coupling y and the quartic…
We review the main features of the QCD phase diagram description, at finite temperature, baryon density and in the presence of a magnetic field, from the point of view of effective models, whose main ingredient is chiral symmetry. We…
In view of various field-theoretic reasons, in the present work, we study the question of if the usual dimensional regularization can be extended to quantum field theories with an ultraviolet cutoff (Poincare-breaking scale) in a way…
In order to check the validity of auxiliary field method in the Nambu--Jona-Lasinio model, the one-loop (=quantum) effects of auxiliary fields to the gap equation are considered with N-component fermion models in 4 and 3 dimensions. N is…
We investigate the phase structure of the Nambu--Jona-Lasinio model at zero temperature, allowing for a two-dimensional spatial dependence of the chiral condensate. Applying the mean-field approximation, we consider various periodic…
This research summarizes work done by myself (Nucl.Phys.{\bf A641} (1998)461), or in collaboration with R. M. Davidson (Phys.Lett.{\bf B348}(1995)163) and H. Weigel and L. Gamberg (Nucl.Phys.{\bf B560}(1999)xx). I will discuss several…
Along with masses of pion and sigma meson modes, their dissociation into quark medium provide a detail spectral structures of the chiral partners. Present article has studied a finite size effect on that detail structure of chiral partners…
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…
In this paper, we study the possibility of an inhomogeneous quark condensate in the 1+1 dimensional Nambu-Jona-Lasinio model in the large-$N_c$ limit at finite temperature $T$ and quark chemical potential $\mu$ using dimensional…
Within the Extended Nambu Jona-Lasinio model we analyse the $1/N_c$-corrections to the leading order result $M_S=2M_Q$ where $M_Q$ is the constituent quark mass.
Dimensional regularization is applied to the Lippmann-Schwinger equation for a separable potential which gives rise to logarithmic singularities in the Born series. For this potential a subtraction at a fixed energy can be used to…
We show that the procedure of regularizing the real part of the euclidean action, while leaving the imaginary part unregularized, leads to a non-analytic and highly singular functional of the fields. It is customary to work with an…