Related papers: Nambu--Jona-Lasinio Model Revisited with a Simple …
Supersymmetric renormalization group (RG) flow equations for the effective superpotential of the three-dimensional Wess-Zumino model are derived at zero and non-zero temperature. This model with fermions and bosons interacting via a Yukawa…
In this work we study the $3+1$-dimensional Nambu-Jona-Lasinio (NJL) model in the mean field-approximation. We carry out calculations using five different regularization schemes (two continuum and three lattice regularization schemes) with…
Superfluid $^3$He is a spin-triplet ($S=1$), p-wave ($L=1$) BCS condensate of Cooper pairs with total angular momentum $J=0$ in the ground state. In addition to the breaking of $U(1)$ gauge symmetry, separate spin or orbital rotation…
We discuss how inflation can emerge from a four-fermion interaction induced by torsion. Inflation can arise from coupling torsion to Standard Model fermions, without any need of introducing new scalar particles beyond the Standard Model.…
We provide a current expansion for the classical equations of motion of the massles Wess-Zumino model. In the low-energy limit, there appears a massive behavior for bosonic degrees of freedom and, at small coupling, the fermion field shows…
We discuss the phase structure (in the $1/N$-expansion) of the Nambu-Jona-Lasinio model in curved spacetime with non-trivial topology ${\cal M}^3 \times {\rm S}^1$. The evaluation of the effective potential of the composite field…
The $\rho\omega$--mixing generated by the isospin breaking of the current quark masses $m_{u} \neq m_{d}$ is studied within the bosonized NJL model in the gradient expansion. The resulting effective meson lagrangian naturally incorperates…
The masses of the low-lying scalar mesons are investigated in the three-flavor Nambu Jona-Lasinio (NJL) model by treating the scalar mesons as composite objects of a quark and an antiquark. It is known that a simple $\bar qq$ picture fails…
For the Nambu--Jona--Lasinio (NJL) model in the proper time regularization scheme the chiral soliton is investigated for the case of three flavors within the framework of the bound state approach to strangeness. For this purpose meson…
We show that the chiral symmetry breaking occurs in the vacuum of the massless Nambu-Jona-Lasinio (NJL) and Thirring models without a Goldstone boson. The basic reason of non-existence of the massless boson is due to the fact that the new…
A less well known variant of the Nambu--Jona-Lasinio model with Nc colors and U(2)L X U(2)R chiral symmetry is studied in 1+1 dimensions. Using semi-classical methods appropriate for the large Nc limit, we determine the vacuum manifold, the…
We investigate the influence of the allowed unphysical meson decay into a quark-antiquark pair of the three flavour Nambu--Jona-Lasinio (NJL) model on its parameter fixing. This decay manifests in a non-vanishing imaginary part of the…
In QCD with two light quarks with application of Bogolubov quasi-averages approach a possibility of spontaneous generation of an effective interaction, leading to the Nambu -- Jona-Lazinio model, is studied. Compensation equations for…
We investigate the properties of neutral and charged pions in a constant background magnetic field mainly at zero temperature within the Nambu--Jona-Lasinio model. In the previous calculations, the Ritus method, involving Schwinger phases…
We study the contribution of a heavy right-handed Majorana neutrino to neutrinoless double beta decay ($0\nu\beta\beta$) via four-fermion effective interactions of Nambu-Jona-Lasinio (NJL) type. In this physical scenario, the sterile…
Nambu-Jona-Lasinio-type models are frequently employed as low-energy models in various research fields. With respect to the theory of the strong interaction, this class of models is indeed often used to analyze the structure of the phase…
We investigate color superconducting phase at high density in the extended Nambu--Jona-Lasinio model for the two flavor quarks. Because of the non-renormalizability of the model, physical observables may depend on the regularization…
The Maximum Entropy Method is applied to dynamical fermion simulations of the (2+1)-dimensional Nambu-Jona-Lasinio model. This model is particularly interesting because at T=0 it has a broken phase with a rich spectrum of mesonic bound…
Nambu-Jona-Lasinio model used to investigate low energy phenomena is nonrenormalizable, therefore the results depend on the regularization parameter in general. A possibility of the finite in four-dimensional limit and even the…
The merits and limitations of the Nambu--Jona-Lasinio model as a model for strong interactions at nonzero density are critically discussed. We present several examples, demonstrating that, while in general the results should not be trusted…