arXiv subjects

M. S. Lukashov

Publications and source records attributed to M. S. Lukashov.

15 recordsLinked to original sources

arXiv2025

The Spin-Spin Dynamics of Glueballs

The masses of pure gauge glueballs are calculated with the use of relativistic string Hamiltonian without fitting parameters. The string tension $σ_f=0.184$~GeV$^2$ in fundamental representation is fixed, using the Necco-Sommer lattice data, and to calculate the vector coupling $α_{\rm V}(r)$ the value of $Λ_{\overline{MS}}^0=238$~MeV ($N_f=0$) is taken. The spin-spin potential, defined via the vacuum correlation function, is shown to produce a screening effect and decrease a hyperfine splittings between tensor and scalar glueballs. The masses of first and second $0^{++}$, $2^{++}$ excitations are predicted. For the ground states the masses $M(0^{++})=1508$~MeV, $M(2^{++})=2292$~MeV (in case A), in agreement with those of $f_0(1500),~f_2(2300)$ are obtained, and the first excitation mass $M(0^{++})=2613$~MeV is predicted. In case B $M(0^{++})=1.669$~MeV, $M(2^{++})=2212$~MeV are obtained.

hep-ph↗

arXiv2024

Colour-electric and colour-magnetic confinement

The basic properties of the confinement mechanism in QCD -- the temperature dependence of the spatial and temporal string tensions ($σ_s(T)$ and $σ_E(T)$) -- are studied in the framework of the Field Correlator Method (FCM). It is shown that both functions are connected respectively to the spatial and temporal parts of the vacuum gluon energy $ε_s$ and $ε_E$ which define their equal values at $T=0$. However at $T>0$ the spatial part is growing with $T$ while the temporal part is destroyed by the hadronic pressure at $T=T_c$ (the deconfinement). Both properties are derived within the same method and are in a good agreement with the corresponding lattice data.

hep-ph↗

arXiv2024

New ideas in nonperturbative QCD -- I

The recent development of the Field Correlator Method (FCM) is discussed, with applications to the most interesting areas of QCD physics obtained in the lattice data and experiment. These areas include: a) the connection of colorelectric confinement with the basic quark and gluon condensates; b) the explicit form of the colorelectric deconfinement at a growing temperature $T$; c) the theory of the colormagnetic confinement at all temperatures; d) the theory of strong decays, the theory of pdf and jets in the instantaneous formalism with confinement. We demonstrate that the FCM with instantaneous formalism and confinement (instead of the light cone formalism and pure perturbation theory) can provide the way to the theory of QCD, which helps to describe world data without phenomenological parameters.

hep-ph↗

arXiv2024

Sound in a Bubbly Hybrid Neutron Star

Increasingly precise astrophysical observations of the last decade in combination with intense theoretical studies allow for drawing a conclusion about potential Quark Matter presence in Neutron Stars interiors. Quark Matter may form the Neutron Star inner core or be immersed in the form of bubbles, or droplets. We consider the second scenario and demonstrate that even a small fraction of quark matter bubbles can lead to a high nonlinearity of the sound wave. Below the bubble resonant frequency the sound speed is lower than the ambient value. At the resonance it sharply grows. The peak is constrained by viscous dissipation. Above the resonance the speed exceeds the pure neutron star matter value. The dispersion equation for the bubbly neutron star compressibility is derived.

hep-ph↗

arXiv2023

Theory of the deconfinement process in QCD

The phenomenon of the deconfinement -- the spectacular drop of the colorelectric string tension at the critical temperature $T_c$ -- is studied within the method of field correlators (FCM) taking into account directly the contribution of the gluon condensate into the hadronic free energy. Using the resulting expressions for the free energy as a sum of the gluon condensate (the vacuum energy) and the hadronic pressure one obtains the possibility to calculate the deconfinement temperature $T_c$ and the temperature behavior of the string tension $σ_E(T)$ and the gluonic condensate $G_2(T)$ below $T_c$. The connection between the string tension and the quark condensate found in the framework of FCM allows the predict also the latter as a function of $T$ . These results are compared to the known lattice data of $T_c$, $σ_E(T)$, $\langle \bar{q}q \rangle(T)$ for hadronic media with different $n_f$ and $m_q$ and in the external magnetic field $eB$. The good agreement of the results of this approach with lattice data is demonstrated.

hep-ph↗

arXiv2020

The Relativistic Cornell-type Mechanism of Exotic Scalar Resonances

The formalism of the coupled $q\bar q$ and the $φφ( π-π$, $K\bar K, πK,...$) scalar channels is formulated, taking into account the ground and radial excited $q\bar q$ poles. The basic role is shown to be played by the transition coefficients $k^{(I)} (q\bar q, |φφ)$, which are calculated using the quark-chiral Lagrangian without free parameters. The resulting method, called the pole projection mechanism (PPM), ensures: 1) one resonance for each $φφ$ channel from the basic $q\bar q$ pole, e.g. the $f_0 (500)$ resonance in the $ππ$ channel; 2) a possibility to have two $φφ$ resonances, coupled to the same $q\bar q$ state, when the channel coupling is taken into account in the meson-meson channels, which yields $f_0 (500)$ and $f_0(980)$ from the same $n\bar n$ pole around 1 GeV; 3) the strong pole shift down for special ($ππ, πK)$ channels due to large transition coefficients $k^{(I)}$, computed in this formalism without free parameters. The parameters of calculated complex poles are in reasonable agreement with the experimental data of the resonances $f_0(500)$, $f_0(980)$, $a_0(980)$, $a_0(1450)$, $K^*_0(700)$, $K^*_0(1430)$, $f_0(1370)$ and $f_0(1710)$.

hep-ph↗

arXiv2020

Scalar mesons in the chiral theory with quark degrees of freedom

The Chiral Confining Lagrangian, based on the chiral theory with quark degrees of freedom, is used to study the spectroscopy of scalar mesons. The formalism does not contain arbitrary fitting parameters and takes into account infinite number of transitions from meson-meson to quark-antiquark states. Starting from known $q\bar q$ poles the transition coefficients ensure the strong shift of the poles for the $ππ$ and much smaller shift for the $K\bar K$ systems. The resulting amplitudes $f_{ππ}$ and $f_{K\bar K}$ are calculated in terms of the $q\bar q$ and the free meson Green's functions. With the account of the $ππ/K\bar{K}$ channel coupling one obtains two resonances: a wide resonance $E_1$ in the range 500-700 MeV and narrow $E_2 $ near 1 GeV, which can be associated with $f_0(500)$ and $f_0(980)$. A similar analysis, applied to the $I=1$ channel, shows that in this case two very close poles in different sheets appear near $E=980$ MeV, which can be associated with the $a_0 (980)$ resonance. The obtained $ππ$ interaction amplitudes, $\operatorname{Re} f_{ππ} (E)$ and $\operatorname{Im} f_{ππ}(E)$ are compared with the known data.

hep-ph↗

arXiv2020

The Rayleigh Bubble in Quark Matter under a Strong Magnetic Field

The transition of QGP from fluid-dynamical regime to freeze-out is accompanied by the onset of instabilities. In the present paper we investigate the impact of the magnetic field on the Rayleigh instability. We show that extremely strong field generated in peripheral heavy ion collisions has an insignificant influence on the Rayleigh bubble dynamics. Magnetic "friction" turns out to be much weaker than the viscous one.

hep-ph↗

arXiv2017

Nonperturbative quark-gluon thermodynamics at finite density

Thermodynamics of the quark-gluon plasma at finite density is studied in the framework of the Field Correlator Method, where thermodynamical effects of Polyakov loops and colormagnetic confinement are taken into account. Having found good agreement with numerical lattice data for zero density, we calculate pressure $P(T,\,μ)$ for $0 <μ< 400$ MeV and $150 <T< 1000$ MeV. For the first time the explicit intergral form is found in this region,demonstrating analytic structure in the complex $μ$ plane. The resulting multiple complex branch points are found at the Roberge-Weiss values of $\operatorname{Im}\,μ$, with $\operatorname{Re}\,μ$ defined by the values of Polyakov lines and colormagnetic confinement.

hep-ph↗

arXiv2017

Color screening in flux tubes and in the color Coulomb potential from the QCD Field Correlators

Colorelectric and Colormagnetic structure of the flux tubes, connecting heavy quark and antiquark, is investigated in the framework of the Field Correlator method which describes all resulting fields in terms of correlators $D^E$ and $D^E_1$. The latter have been computed via gluelumps, which allows to predict the resulting distribution of color fields $\mathbf{E} (\mathbf{r}),$ and colormagnetic currents $\mathbf{k} (\mathbf{r})$ in the flux tubes. It is shown, that at large distances $r\gg λ\approx 0.2$ fm the whole structure of fields and relations between them is similar to that of the dual superconductor theory, but the basic dynamics, including small distances, is given by field correlators of the real stochastic vacuum. The important contradiction between the strong screening of color fields in the width of flux tubes and almost no screening in the perturbative $Q\bar Q$ potential is resolved.

hep-ph↗

arXiv2017

Colormagnetic confinement in the quark-gluon thermodynamics

Nonperturbative effects in the quark-gluon thermodynamics are studied in the framework of Vacuum Correlator Method. It is shown, that two correlators: colorelectric $D_1^E(x)$ and colormagnetic $D^H(x)$, provide the Polyakov line and the colormagnetic confinement in the spatial planes respectively. As a result both effects produce the realistic behavior of $P(T)$ and $s(T)$, being in good agreement with numerical lattice data.

hep-ph↗

arXiv2017

Nonperturbative SU(3) thermodynamics and the phase transition

The $SU(3)$ equation of state ($P(T),\,s(T),\,I(T)$) are calculated within the Field Correlator Method both in the confined and the deconfined phases. The basic dynamics in our approach is contained in the vacuum correlators, both of the colorelectric (CE) and colormagnetic (CM) types, which ensure CE and CM confinement below $T_c$ and CM confinement and Polyakov loops above $T_c$. The resulting values of $T_c$ and $P(T),\,I(T)$, $s(T)$ are in good agreement with lattice measurements.

hep-ph↗

arXiv2016

Dynamical role of Polyakov loops in the QCD thermodynamics

Polyakov loops $L_a(T), a=3,8,...$ are shown to give the most important nonperturbative contribution to the thermodynamic potentials. Derived from the gluonic field correlators they enter as factors into free energy. It is shown in the $SU(3)$ case that $L_a (T)$ define to a large extent the behavior of the free energy and the trace anomaly $I(T)$, most sensitive to nonperturbative effects.

hep-lat↗

arXiv2016

Fluctuation sound absorption in quark matter

We investigate the sound absorption in quark matter due to the interaction of the sound wave with the precritical fluctuations of the diquark-pair field above $T_c$. The soft collective mode of the pair field is derived using the time dependent Ginzburg-Landau functional with random Langevin forces. The strong absorption near the phase transition line may be viewed as a manifestation of the Mandelshtam-Leontovich slow relaxation time theory.

hep-ph↗

arXiv2015

Damping and Decoherence in Neutron Oscillations

An analysis is made of the role played by the gas environment in neutron-mirror-neutron and neutron-antineutron oscillations. In the first process the interaction with the ambient medium induces a refraction energy shift which plays the role of an extra magnetic field. In the second process antineutron annihilation in practice might lead to strong decoherence, which should be taken into account in experiments with free neutrons looking for the neutron to antineutron transformation.

hep-ph↗