Searcharxiv⌕ Search

arXiv subjects

S. V. Molodtsov

Publications and source records attributed to S. V. Molodtsov.

At least 19 recordsLinked to original sources
arXiv2014

Condensated fermion system in the model of four-quark interaction with large correlation length

Studying a model of four-quark interaction with large correlation length we find out both the features peculiar an unitary fermi gas and the specific anomalous properties of the fermi systems with a fermion condensate. It is argued that a possibility of phase transition originated by interface between the Fermi sphere and fermion condensate appears in such quark systems. The results obtained could be instrumental for phenomenological applications in view of our conclusion about approximately the same behavior of the dynamical characteristics of quark ensembles with different four-quark interaction forms in a practical interval of coupling constant.

hep-ph↗
arXiv2014

Quantum liquids resulted from the models with four-fermion interaction

A (nearly) perfect liquid discovered in the experements with ultrarelativistic heavy ion collisions is investigated by studying the quark ensembles with four-fermion interection as a fundamental theoretical approach. The comparative analysis of several quantum liquid models is performed and it results in the conclusion that the presence of gas---liquid phase transition is their characteristic feature. The problem of instability of the quark droplets of small quark number is discussed and argued to be rooted in the chiral soliton formation. An existence of mixed phase of the vacuum and baryon matter is proposed as a possible reason of the latter stability.

hep-ph↗
arXiv2014

Quark ensembles with infinite correlation length

By studying quark ensembles with infinite correlation length we formulate the quantum field theory model that, as we show, is exactly integrable and develops an instability of its standard vacuum ensemble (the Dirac sea). We argue such an instability is rooted in high ground state degeneracy (for 'realistic' space-time dimensions) featuring a fairly specific form of energy distribution, and with the cutoff parameter going to infinity this inherent energy distribution becomes infinitely narrow and leads to large (unlimited) fluctuations. Analysing some possible vacuum ensembles such as the Dirac sea, neutral ensemble, color superconducting and BCS states we find out the strong arguments in favor of the BCS state as the ground state of color interacting quark ensemble.

hep-ph↗
arXiv2013

Non-Abelian color fields from relativistic color charge configurations in the classical limit

We study the dynamics of color fields as generated by simple configurations of relativistic particles with Abelian and non-Abelian (SU(2)) charges in the classical limit. We find that chromodynamic (non-Abelian) systems generally show Coulomb-like features by analogy with electrodynamics. A peculiar feature in the non-Abelian case is the additional strength of the chromoelectric and chromomagnetic fields caused by the contribution of changing the color charge. This change of color SU(2) charges results in a rotation of the color vector which is getting very fast at close partonic distances. The presence of this non-Abelian additional term in the chromoelectric and chromomagnetic fields creates a 'color charge glow', which is manifested as a distinct color wave disturbance arising due to the finite distance at which the color interaction becomes active. This situation may be relevant to the hadronization phase in ultrarelativistic heavy-ion collisions, where the partonic state is governed by strong local color fluctuations.

nucl-th↗
arXiv2013

Studying quark condensates within models of four-quark interaction

Analysing two models of four-quark interactions which are of intrinsic difference in the behaviours of their correlation lengths some issues of quark condensations are considered. It is demonstrated that the quark condensates substantially are not sensitive to the details of those interactions in the range of coupling constants interesting for applications.

hep-ph↗
arXiv2011

Thermodynamics of quark quasi-particles ensemble

The features of hot and dense gas of quarks which are considered as the quasi-particles of the model Hamiltonian with four-fermion interaction are studied. Being adapted to the Nambu-Jona-Lasinio model this approach allows us to accommodate a phase transition similar to the nuclear liquid-gas one at the proper scale and to argue an existence of the mixed (inhomogeneous) phase of vacuum and normal baryonic matter as a plausible scenario of chiral symmetry (partial) restoration. Analyzing the transition layer between two phases we estimate the surface tension coefficient and speculate on the possible existence of quark droplet.

hep-ph↗
arXiv2011

Towards thermodynamics of the quark quasi-particles

Some features of hot and dense gas of quarks which are considered as the quasi-particles of the model Hamiltonian with four-fermion interaction are studied. Being adapted to the Nambu-Jona-Lasinio model this approach allows us to accommodate a phase transition similar to the nuclear liquid-gas one at the proper scale and to argue an existence of the mixed phase of vacuum and normal baryonic matter as a plausible scenario of chiral symmetry (partial) restoration. Analyzing the transition layer between two phases we estimate the surface tension coefficient and discuss the possibility of quark droplet formation.

hep-ph↗
arXiv2010

Hot and dense gas of quark quasi-particles

Some features of hot and dense gas of quarks which are considered as the quasi-particles of the model Hamiltonian with four-fermion interaction are studied. Being adapted to the Nambu-Jona-Lasinio model this approach allows us to accommodate a phase transition similar to the nuclear liquid-gas one at the proper scale. It allows us to argue an existence of the mixed phase of vacuum and baryonic matter (even at zero temperature) as a plausible scenario of chiral symmetry (partial) restoration.

hep-ph↗
arXiv2009

Just one more approach to calculating the QCD ground state

The quark behaviour in the background of intensive stochastic gluon field is studied. An approximate procedure for calculating the effective Hamiltonian is developed and the corresponding ground state within the Hartree-Fock-Bogolyubov approach is found. The comparative analysis of various model Hamiltonian is given and transition to the chiral limit in the Keldysh model is discused in detail. We study response to the process of filling up the Fermi sphere with quarks, calculate the vacuum pressure and demonstrate the existence of filled-in state degenerate with the vacuum one.

hep-ph↗
arXiv2009

Bogolyubov-Hartree-Fock approach to studying the QCD ground state

The quark's behaviour while influenced by a strong stochastic gluon field is analyzed. An approximate procedure for calculating the effective Hamiltonian is developed and the corresponding ground state within the Hartree-Fock-Bogolyubov approach is found. The comparative analysis of various Hamiltonian models is given and transition to the chiral limit in the Keldysh model is discussed in detail.

hep-ph↗
arXiv2009

Exploring meson correlators in the model with four-quark interaction Lagrangian

Meson correlation functions are studied in the model with four-fermion interaction Lagrangian. We demonstrate that despite the singular character of system mean energy and corresponding quark condensate found out the meson observables are finite, quite well identified and compatible with experimental energy scale. It allows one to use the similar model Hamiltonians for describing the nonequilibrium features of quark/hadron systems which reveal themselves in studying ultrarelativistic heavy ion collisions. The analytical results for meson correlation functions in the Keldysh model are given.

hep-ph↗
arXiv2008

New arrangement of common approach to calculating the QCD ground state

The quark behaviour in the background of intensive stochastic gluon field is studied. An approximate procedure for calculating the effective Hamiltonian is developed and the corresponding ground state within the Hartree-Fock-Bogolyubov approach is found. The comparative analysis of various model Hamiltonian is given and transition to the chiral limit in the Keldysh model is discused in detail.

hep-ph↗
arXiv2007

Gluon condensate behaviour at filling the Fermi sphere up

The impact of filling up the Fermi sphere with the quarks, which dynamically generated their masses on the instanton liquid at finite temperature and baryonic/quark number density, is investigated. It is demonstrated, in particular, that the boundary of chiral symmetry restoration phase transition is shifted to the larger (about 100 MeV more) value of quark chemical potential compared to the magnitude inherent in the Nambu-Jona-Lasinio model.

hep-ph↗
arXiv2007

Towards self-consistent definition of instanton liquid parameters

The possibility of self-consistent determination of instanton liquid parameters is discussed together with the definition of optimal pseudo-particle configurations and comparing the various pseudo-particle ensembles. The weakening of repulsive interactions between pseudo-particles is argued and estimated.

hep-ph↗
arXiv2007

Instanton Liquid at Finite Temperature and Chemical Potential of Quarks

Instanton liquid in heated and strongly interacting matter is studied using the variational principle. The dependence of the instanton liquid density (gluon condensate) on the temperature and the quark chemical potential is determined under the assumption that, at finite temperatures, the dominant contribution is given by an ensemble of calorons. The respective one-loop effective quark Lagrangian is used.

hep-ph↗
arXiv2006

Towards light scalar meson structure in terms of quark and gluon degrees of freedom

The origin of the lightest scalar mesons is studied in the framework of instanton liquid model (ILM) of the QCD vacuum. The impact of vacuum excitations on the sigma-meson features is analyzed in detail. In particular, it is noticed that the changes produced in the scalar sector may unexpectedly become quite considerable in spite of insignificant values of corrections to the dynamical quark masses and then the medley of sigma-meson and those excitations may reveal itself as broad resonance states of vitally different masses.

hep-ph↗