Searcharxiv⌕ Search

arXiv subjects

Sergii Kutnii

Publications and source records attributed to Sergii Kutnii.

6 recordsLinked to original sources
arXiv2025

A possibility for grand unification and non-Higgs mass generation in a Nambu-Jona-Lasinio-like theory of fermions interacting with current metric field

Grand unification possibilities in Nambu-Jona-Lasinio-like models are studied. To address the problem of vector boson masses and nonrenormalizability of the theory, algebraic formalism encompassing the effective action, Schwinger-Keldysh path integral, and Bogoliubov-Parasiuk-Hepp-Zimmerman renormalization is constructed. A new NJL-like model: the theory of current metric field interacting with fermions is proposed. Bosonization in this model can produce massless vector bosons under certain conditions which makes it a candidate grand unified theory. Both Higgs and non-Higgs effects can contribute to particle masses.

hep-ph↗
arXiv2023

Bosonization, effective action, and R-operation in a generalized Nambu-Jona-Lasinio model

Bosonization in a theory with four-fermion interaction of Nambu-Jona-Lasinio type with additional U(N) symmetry is studied. It is demonstrated that bosonization is not uniquely determined by the interaction terms due to Fierz identities. Effective action including both fermions and composite fields is constructed. R-operation renormalization scheme is developed for the effective action. A generalization of bosonization transformation called composite fields formalism is proposed and demonstrated to be applicable to any field theory. Nambu-Jona-Lasinio model with three-fermion composite fields is studied as an example. Fierz identities for sixth-order combinations of fermions are derived.

hep-th↗
arXiv2015

Soap bubble hadronic states in a QCD-motivated Nambu-Jona-Lasinio model

Inhomogeneous solutions of the gap equation in the mean field approach to Nambu-Jona-Lasinio model are studied. An approximate Ginzburg-Landau-like gap equation is obtained and the domain wall solution is found. Binding of fermions to the domain wall is demonstrated. Compact domain wall with bound fermions is studied and stabilisation by fermion pressure is demonstrated which opens a possibility for existence of "soap bubble" hadronic states.

hep-th↗
arXiv2011

Domain Wall in Nambu-Jona-Lasinio Model

The approximation for the NJL gap equation that was developed in our previous paper allows us to investigate vacuum inhomogeneities in the mean field approach. The simplest case of a domain wall is studied thoroughly. The Jackiw-Rebbi problem which arises in treatment of the fermions' interaction with the domain wall is solved explicitly and the entire spectrum of bound states is described. It is estabilished that under our assumptions no bound states exist at the domain wall, however higher-order corrections may make them appear. Thus existence of the quark bound states at domain walls may be a good test for subtle features of QCD.

hep-th↗
arXiv2011

Inhomogeneous Vacuum States in Nambu-Jona-Lasinio Model

The mean field approach to the Nambu-Jona-Lasinio model is developed systematically. Approximate mean field action is obtained, based on the study of divergencies in the mean field action. A special scalar case of the approximate motion equations is studied and inhomogenouous solutions are discussed. It is shown that the model can have inhomogeneous vacuum configurations which leads to bound fermionic states.

hep-th↗