In this paper, we study the properties of media with chiral imbalance parametrized by chiral chemical potential. It is shown that depending on the strength of interaction between constituents in the ...media the chiral chemical potential either creates or enhances dynamical chiral symmetry breaking. Thus, the chiral chemical potential plays the role of the catalyst of dynamical chiral symmetry breaking. Physically, this effect results from the appearance of the Fermi surface and additional fermion states on this surface, which take part in dynamical chiral symmetry breaking. An interesting conclusion which can be drawn is that at sufficiently small temperature chiral plasma is unstable with respect to condensation of Cooper pairs and dynamical chiral symmetry breaking even for vanishingly small interactions between constituents.
In this paper we consider the influence of relativistic rotation on the confinement-deconfinement transition in gluodynamics within lattice simulation. We perform the simulation in the reference ...frame which rotates with the system under investigation, where rotation is reduced to external gravitational field. To study the confinement-deconfinement transition, the Polyakov loop and its susceptibility are calculated for various lattice parameters and the values of angular velocities that are characteristic for heavy-ion collision experiments. Different types of boundary conditions (open, periodic, Dirichlet) are imposed in directions, orthogonal, to rotation axis. Our data for the critical temperature are well described by a simple quadratic function Tc(Ω)/Tc(0) = 1 + C2Ω2 with C2 > 0 for all boundary conditions and all lattice parameters used in the simulations. From this we conclude that the critical temperature of the confinement-deconfinement transition in gluodynamics increases with increasing angular velocity. This conclusion does not depend on the boundary conditions used in our study and we believe that this is universal property of gluodynamics.
We study the electromagnetic conductivity of QGP in a magnetic background by lattice simulations with Nf = 2 + 1 dynamical rooted 2-stout smeared staggered fermions at the physical point. We study ...the correlation functions of the electromagnetic currents at T = 200 , 250 MeV and use the Tikhonov approach to extract the conductivity. The conductivity is found to rise with the magnetic field in the parallel direction and to decrease in the transverse direction, giving evidence for both the chiral magnetic effect and the magnetoresistance phenomenon in QGP. We also estimate the chiral charge relaxation time in QGP.
A
bstract
In this paper we study the SU(3)-gluodynamics shear viscosity temperature dependence on the lattice. To do so, we measure the correlation functions of the energy-momentum tensor in the ...range of temperatures
T /T
c
∈ 0
.
9
,
1
.
5. To extract the shear viscosity we used two approaches. The first one is to fit the lattice data with a physically motivated ansatz for the spectral function with unknown parameters and then determine the shear viscosity. The second approach is to apply the Backus-Gilbert method allowing to extract the shear viscosity from the lattice data nonparametrically. The results obtained within both approaches agree with each other. Our results allow us to conclude that within the range
T /T
c
∈ 0
.
9
,
1
.
5 the SU(3)-gluodynamics reveals the properties of a strongly interacting system, which cannot be described perturbatively, and has the ratio
η/s
close to the value 1
/
4
π
of the
N
= 4 Supersymmetric Yang-Mills theory.
In this paper, we carry out a low-temperature scan of the phase diagram of dense two-color QCD with Nf=2 quarks. The study is conducted using lattice simulation with rooted staggered quarks. At small ...chemical potential, we observe the hadronic phase, where the theory is in a confining state, chiral symmetry is broken, the baryon density is zero, and there is no diquark condensate. At the critical point μ=mπ/2, we observe the expected second-order transition to Bose-Einstein condensation of scalar diquarks. In this phase, the system is still in confinement in conjunction with nonzero baryon density, but the chiral symmetry is restored in the chiral limit. We have also found that in the first two phases the system is well described by chiral perturbation theory. For larger values of the chemical potential, the system turns into another phase, where the relevant degrees of freedom are fermions residing inside the Fermi sphere, and the diquark condensation takes place on the Fermi surface. In this phase, the system is still in confinement, chiral symmetry is restored, and the system is very similar to the quarkyonic state predicted by SU(Nc) theory at large Nc.
In this paper, the temperature dependence of the SU(3) gluodynamics bulk viscosity is studied within lattice simulations. To carry out this study, we measure the correlation function of the trace of ...the energy-momentum tensor for a set of temperatures within the range T/Tc∈(0.9,1.5). To extract the bulk viscosity from the correlation function, we apply the Backus-Gilbert method and the Tikhonov regularization method. We show that the ratio ζ/s is small in the region T/Tc≥1.1–1.2, and in the vicinity of the transition T/Tc≤1.1–1.2 it quickly rises. Our results are in agreement with previous lattice studies and in a reasonable agreement with other phenomenological approaches. Obtained values of the bulk viscosity are significantly larger than perturbative results, which confirms that quark-gluon plasma is a strongly correlated system.
In this paper we report on lattice simulations of SU(3)-QCD with nonzero chiral chemical potential. We focus on the influence of the chiral chemical potential on the confinement/deconfinement phase ...transition and the breaking/restoration of chiral symmetry. The simulation is carried out with dynamical Wilson fermions. We find that the critical temperature rises as the chiral chemical potential grows.
The development of the method of electric explosion of wires and research results concerning preparation of nanopowders by this method has been reviewed. The method is highly productive (up to ...200g/h), provides powders with an average particle size of 20-100nm, and requires an energy consumption of about 25kWh/kg. Several characteristics of the nanopowders will be given and their applications will be exemplified too.PUBLICATION ABSTRACT
A
bstract
In this paper we study the interactions among a static quark-antiquark pair in the presence of dense two-color quark matter with lattice simulation. To this end we compute Polyakov line ...correlation functions and determine the renormalized color averaged, color singlet and color triplet grand potentials. The color singlet grand potential allows us to elucidate the number of quarks induced by a static quark antiquark source, as well as the internal energy of such a pair in dense quark matter. We furthermore determine the screening length, which in the confinement phase is synonymous with the string breaking distance. The screening length is a decreasing function of baryon density, due to the possibility to break the interquark string via a scalar diquark condensate at high density. We also study the large distance properties of the color singlet grand potential i a dense medium and find that it is well described by a simple Debye screening formula, parameterized by a Debye mass and an effective coupling constant. The latter is of order of unity, i.e. even at large density two-color quark matter is a strongly correlated system.
The sphaleron transition rate in gluodynamics at the temperature
T
/
T
c
= 1.24 has been calculated by lattice simulation. The calculations involve the Kubo formula, which relates the sphaleron ...transition rate to the correlation function of the topological charge density. The gradient flow method has been used to calculate the correlation function of the topological charge density. The Kubo formula has been inverted by the Backus–Gilbert method. The results have been compared to those obtained by other methods.
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