arXiv subjects

E. V. Luschevskaya

Publications and source records attributed to E. V. Luschevskaya.

At least 19 recordsLinked to original sources

arXiv2024

Vector $K^{*}$ mesons in external magnetic field from SU(3) gluodynamics

We explore the ground state energies of the neutral and charged vector $K^{*}$ mesons in the external abelian magnetic field of QCD scale using overlap fermions. We attempt to calculate the magnetic moment and the magnetic dipole polarizability of the $K^{*0}$ and $\bar{K}^{*0}$ mesons and investigate their dependence on the ratio of the strange quark mass to the light quark mass. It is found that the ground state energy and the magnetic dipole polarizability depends on the meson spin projection on the magnetic field axis. This leads to the appearance of dileptonic asymmetry, which can be characterized by the tensor polarizability estimated for the $K^{*0}$ mesons. We obtain that the $g$-factor of the vector $K^{*\pm}$ mesons depends on the $m_s/m_u$ value. Also we do not observe any evidence of the tachyon mode existence for the strange vector mesons.

hep-lat↗

arXiv2018

Tensor polarizability of the vector mesons from $SU(3)$ lattice gauge theory

The magnetic dipole polarizabilities of the vector $ρ^0$ and $ρ^{\pm}$ mesons in $SU(3)$ pure gauge theory are calculated in the article. Based on this the authors explore the contribution of the dipole magnetic polarizabilities to the tensor polarization of the vector mesons in external abelian magnetic field. The tensor polarization leads to the dilepton asymmetry observed in non-central heavy ion collisions and can be also estimated in lattice gauge theory.

hep-lat↗

arXiv2017

Determination of the properties of vector mesons in external magnetic field by Quenched $SU(3)$ Lattice QCD

We investigate the ground state energies of vector $ρ^{\pm}$ and $K^{\pm *}$ mesons depending on the magnetic field value in the $SU(3)$ lattice gauge theory. It has been shown that the energy of a vector particle depends on its spin projection on the field axis. The magnetic dipole polarizability and hyperpolarizabilities give significant contributions to the energy value which prevents the formation of the charged vector meson condensate at high magnetic fields. We calculate the g-factor of $ρ^{\pm}$ and $K^{\pm*}$ mesons and the dipole magnetic polarizability of $ρ^{\pm}$ mesons.

hep-lat↗

arXiv2017

The Evolution of Meson Masses in a Strong Magnetic Field

Spectra of $q \bar{q}$ hadrons are investigated in the framework of the Hamiltonian obtained from the relativistic path integral in external homogeneous magnetic field. The spectra of all 12 spin-isospin s-wave states, generated by $π$ and $ρ$ mesons with different spin projections, are studied both analytically and numerically on the lattice as functions of (magnetic field) $eB$. Results are in agreement and demonstrate three types of behavior, with characteristic splittings predicted by the theory.

hep-ph↗

arXiv2016

Magnetic polarizability of pion

We explore the energy dependence of $π$ mesons off the background abelian magnetic field on the base of quenched SU(3) lattice gauge theory and calculate the magnetic dipole polarizability of charged and neutral pions for various lattice volumes and lattice spacings. The contribution of the magnetic hyperpolarizability to the neutral pion energy has been also found.

hep-lat↗

arXiv2015

Current progress in laser cooling of antihydrogen

We discuss laser cooling methods of (anti)hydrogen and its importance for current and future experiments. The exploration of antimatter presents a great interest for $CERN$ and $GSI$ experiments aimed at check of quantum mechanics laws, fundamental symmetries of nature and gravity and investigations in atomic and nuclear physics. The spectral transition $1S\rightarrow 2P$ in $\bar{H} (H)$ atom is the most suitable for laser cooling due to a small lifetime of $2P$ state and insignificant ionization losses. However the pulsed and continuous laser sources at Lyman-$α$ wavelength do not possess enough power for fast and efficient cooling. The small power of laser sources at $λ=121.6\ \nm$ is poor technical problem associated with a complexity of generation scheme of such radiation, which arises due to absence of nonlinear $BBO$ crystals at this wavelength. The advances in this area will completely destine the future progress of the experiments aimed at study of antimatter.

physics.atom-ph↗

arXiv2015

Magnetic polarizabilities of light mesons in $SU(3)$ lattice gauge theory

We investigate the masses (ground state energies) of neutral pseudoscalar and vector meson in $SU(3)$ lattice gauge theory in strong abelian magnetic field. The energy of $ρ^0$ meson with zero spin projection $s_z=0$ on the axis of the external magnetic field decreases, while the energies with non-zero spins $s_z=-1$ and $+1$ increase with the field. The energy of $π^0$ meson decrease as a function of the magnetic field. We calculated the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume $18^4$. For $ρ^0$ with spin $|s_z|=1$ and $π^0$ meson the extrapolations to zero lattice spacing have been done. We do not observe any evidence in favour of tachyonic mode existence.

hep-lat↗

arXiv2014

$ρ$ mesons in strong abelian magnetic field in SU(3) lattice gauge theory

We explore the masses of neutral and charged $ρ$ mesons in strong abelian magnetic field in $SU(3)$ gluodynamics. The behaviour of the ground state energy of these particles in the external magnetic field depends on its spin projection $s_z$ on the axis of external magnetic field. The masses of $ρ^0$ meson with $s_z=\pm 1$ increase with the field. The masses of $ρ^{\pm}$ mesons with zero spin also grow with the magnetic field. The ground state energies of $ρ^{-}$ meson with $s_z=-1$ and $ρ^{+}$ meson with $s_z=+1$ diminish as a function of the field, while the energies of $ρ^{+}$ meson with $s_z=-1$ and $ρ^{-}$ meson with $s_z=+1$ rise with the field value.

hep-lat↗

arXiv2014

The $ρ$ and $A$ mesons in strong abelian magnetic field in SU(2) lattice gauge theory

We calculated correlators of vector, axial and pseudoscalar currents in external strong abelian magnetic field according to SU(2) gluodynamics. The masses of neutral $ρ$ and $A$ mesons with various spin projections to the axis parallel to the external magnetic field B have been calculated. We found that the masses of neutral mesons with zero spin $s=0$ decrease in increasing magnetic field, while the masses of the $ρ$ and $A$ mesons with spin $s=\pm 1$ increase in the mentioned field. Also we performed extrapolation and renormalization of masses on the lattice.

hep-lat↗

arXiv2013

The influence of defects on the conductivity of graphene within the effective theory approach

The results of the simulations by Monte Carlo method of graphene with structural defects are presented. The calculations are performed within an effective quantum field theory with non-compact $3\hm + 1$--dimensional Abelian gauge field and $2\hm + 1$--dimensional Kogut-Susskind fermions. It was found that defects shift the phase transition point semimetal-insulator towards higher values of a substrate permittivity.

cond-mat.str-el↗

arXiv2013

Neutral $ρ$ and $A$ mesons in magnetic field in SU(2) lattice gauge theory

Correlators of vector, axial and pseudoscalar currents have been calculated in external strong magnetic field in SU(2) gluodynamics on the lattice. Neutral $ρ$ and $A$ meson masses with a zero spin projection to the axis parallel to the external magnetic field $B$ are calculated. The mass of the neutral $ρ$ meson with zero spin decreases with increasing of the magnetic field for available values of the magnetic field $eB\lesssim 2-2.5\, \Gev^2$, such behavior is necessary for a condensation of $ρ$ mesons in a strong magnetic field.

hep-lat↗

arXiv2012

Numerical study of the conductivity of graphene monolayer within the effective field theory approach

We report on the direct numerical measurements of the conductivity of graphene monolayer. Our numerical simulations are performed in the effective lattice field theory with noncompact 3 + 1-dimensional Abelian lattice gauge fields and 2 + 1-dimensional staggered lattice fermions. The conductivity is obtained from the Green-Kubo relations using the Maximum Entropy Method. We find that in a phase with spontaneously broken sublattice symmetry the conductivity rapidly decreases. For the largest value of the coupling constant used in our simulations g = 4.5, the DC conductivity is less than the DC conductivity in the weak-coupling phase (at g < 3.5) by at least three orders of magnitude.

cond-mat.str-el↗

arXiv2011

$N_f = 2+1+1$ flavours of twisted mass quarks: cut-off effects at tree-level of perturbation theory

We present a calculation of cut-off effects at tree-level of perturbation theory for the K and D mesons using the twisted mass formulation of lattice QCD. The analytical calculations are performed in the time-momentum frame. The relative sizes of cut-off effects are compared for the pion, the kaon and the D meson masses. In addition, different realizations of maximal twist condition are considered and the corresponding cut-off effects are analyzed.

hep-lat↗

arXiv2010

Magnetic-Field-Induced insulator-conductor transition in SU(2) quenched lattice gauge theory

We study the correlator of two vector currents in quenched $SU\lr{2}$ lattice gauge theory with a chirally invariant lattice Dirac operator with a constant external magnetic field. It is found that in the confinement phase the correlator of the components of the current parallel to the magnetic field decays much slower than in the absence of a magnetic field, while for other components the correlation length slightly decreases. We apply the maximal entropy method to extract the corresponding spectral function. In the limit of zero frequency this spectral function yields the electric conductivity of the quenched theory. We find that in the confinement phase the external magnetic field induces nonzero electric conductivity along the direction of the field, transforming the system from an insulator into an anisotropic conductor. In the deconfinement phase the conductivity does not exhibit any sizable dependence on the magnetic field.

hep-lat↗

arXiv2010

Quark electric dipole moment induced by magnetic field

We show numerically that quarks develop an electric dipole moment in the direction of a sufficiently intense magnetic field due to local fluctuations of topological charge. This anomalous CP-odd effect is a spin analogue of the Chiral Magnetic Effect in QCD.

hep-ph↗

arXiv2009

Numerical study of chiral symmetry breaking in non-Abelian gauge theory with background magnetic field

We investigate the effect of a uniform background magnetic field on the chiral symmetry breaking in SU(2) Yang-Mills theory on the lattice. We observe that the chiral condensate grows linearly with the field strength B up to \sqrt{e B} = 3 GeV as predicted by chiral perturbation theory for full QCD. As the temperature increases the coefficient in front of the linear term gets smaller. In the magnetic field near-zero eigenmodes of the Dirac operator tend to have more regular structure with larger (compared to zero-field case) Hausdorff dimensionality. We suggest that the delocalization of near-zero eigenmodes plays a crucial role in the enhancement of the chiral symmetry breaking.

hep-lat↗

arXiv2009

Numerical study of chiral magnetic effect in quenched SU(2) lattice gauge theory

A possible experimental observation of the chiral magnetic effect in heavy ion collisions at RHIC was recently reported by the STAR Collaboration. We study signatures of this effect in SU(2) lattice gluodynamics with the chirally invariant Dirac operator. We find that at zero temperature the local fluctuations of an electric current of quarks and chirality fluctuations increase with external Abelian magnetic field. The external magnetic field leads to spatial separation of the quark's electric charges. The separation increases with the strength of the magnetic field. As temperature gets higher the dependence of these quantities on the strength of the magnetic field becomes weaker. In the deconfinement phase the local fluctuations of the chiral density and of the spatial components of the quarks electric current are large and are almost independent on the external magnetic field. The local fluctuations of the electric charge density decrease with the strength of the magnetic field in this phase.

hep-lat↗

arXiv2009

Chiral magnetization of non-Abelian vacuum: a lattice study

The chiral magnetization properties of cold and hot vacua are studied using quenched simulations in lattice Yang-Mills theory. In weak external magnetic fields the magnetization is proportional to the first power of the magnetic field. We evaluate numerically the coefficient of the proportionality (the chiral susceptibility) using near-zero eigenmodes of overlap fermions. We found that the product of the chiral susceptibility and the chiral condensate equals to 46(3) MeV. This value is very close to the phenomenological value of 50 MeV. In strong fields the magnetization is a nonlinear function of the applied magnetic field. We find that the nonlinear features of the magnetization are well described by an inverse tangent function. The magnetization is weakly sensitive to temperature in the confinement phase.

hep-lat↗