8,403 research outputs found
Lattice QCD thermodynamics at finite chemical potential and its comparison with Experiments
We compare higher moments of baryon numbers measured at the RHIC heavy ion
collision experiments with those by the lattice QCD calculations. We employ the
canonical approach, in which we can access the real chemical potential regions
avoiding the sign problem. In the lattice QCD simulations, we study several
fits of the number density in the pure imaginary chemical potential, and
analyze how these fits affects behaviors at the real chemical potential. In the
energy regions between =19.6 and 200 GeV, the susceptibility
calculated at is consistent with experimental data at , while the kurtosis shows similar behavior with that of the
experimental data in the small regions . The
experimental data at 11.5 shows quite different behavior. The
lattice result in the deconfinement region,, is far from
experimental data
Temperature dependence of the axial magnetic effect in two-color quenched QCD
The Axial Magnetic Effect is the generation of an equilibrium dissipationless
energy flow of chiral fermions in the direction of the axial (chiral) magnetic
field. At finite temperature the dissipationless energy transfer may be
realized in the absence of any chemical potentials. We numerically study the
temperature behavior of the Axial Magnetic Effect in quenched SU(2) lattice
gauge theory. We show that in the confinement (hadron) phase the effect is
absent. In the deconfinement transition region the conductivity quickly
increases, reaching the asymptotic behavior in a deep deconfinement
(plasma) phase. Apart from an overall proportionality factor, our results
qualitatively agree with theoretical predictions for the behavior of the energy
flow as a function of temperature and strength of the axial magnetic field.Comment: 5 pages, 1 figur
Study of lattice QCD at finite baryon density using the canonical approach
At finite baryon density lattice QCD first-principle calculations can not be
performed due to the sign problem. In order to circumvent this problem, we use
the canonical approach, which provides reliable analytical continuation from
the imaginary chemical potential region to the real chemical potential region.
We briefly present the canonical partition function method, describe our
formulation, and show the results, obtained for two temperatures: and in lattice QCD with two flavors of improved Wilson
fermions.Comment: 8 pages, 4 figures, Contribution to XIIth Quark Confinement and the
Hadron Spectru
Lattice QCD at finite baryon density using analytic continuation
We simulate lattice QCD with two flavors of Wilson fermions at imaginary
baryon chemical potential. Results for the baryon number density computed in
the confining and deconfining phases at imaginary baryon chemical potential are
used to determine the baryon number density and higher cumulants at the real
chemical potential via analytical continuation.Comment: 8 pages, 8 figures, Contribution to ICNFP2017, to be published in EPJ
Web of Conference
Phase structure of electroweak vacuum in a strong magnetic field: the lattice results
Using first-principle lattice simulations, we demonstrate that in the
background of a strong magnetic field (around 10^{20} T), the electroweak
sector of the vacuum experiences two consecutive crossover transitions
associated with dramatic changes in the zero-temperature dynamics of the vector
W bosons and the scalar Higgs particles, respectively. Above the first
crossover, we observe the appearance of large, inhomogeneous structures
consistent with a classical picture of the formation of W and Z condensates
pierced by vortices. The presence of the W and Z condensates supports the
emergence of the exotic superconducting and superfluid properties induced by a
strong magnetic field in the vacuum. We find evidence that the vortices form a
disordered solid or a liquid rather than a crystal. The second transition
restores the electroweak symmetry. Such conditions can be realized in the
near-horizon region of the magnetized black holes.Comment: 10 page
Inhomogeneity of rotating gluon plasma and Tolman-Ehrenfest law in imaginary time: lattice results for fast imaginary rotation
We present the results of first-principle numerical simulations of Euclidean
SU(3) Yang-Mills plasma rotating with a high imaginary angular frequency. The
rigid Euclidean rotation is introduced via ``rotwisted'' boundary conditions
along imaginary time direction. The Polyakov loop in the co-rotating Euclidean
reference frame shows the emergence of a spatially inhomogeneous
confining-deconfining phase through a broad crossover transition. A
continuation of our numerical results to Minkowski spacetime suggests that the
gluon plasma, rotating at real angular frequencies, produces a new
inhomogeneous phase possessing the confining phase near the rotation axis and
the deconfinement phase in the outer regions. The inhomogeneous phase structure
has a purely kinematic origin, rooted in the Tolman-Ehrenfest effect in a
rotating medium. We also derive the Euclidean version of the Tolman-Ehrenfest
law in imaginary time formalism and discuss two definitions of temperature at
imaginary Euclidean rotation.Comment: 12 pages, 7 figure
Generation of electric current by magnetic field at the boundary: quantum scale anomaly vs. semiclassical Meissner current
The scale (conformal) anomaly can generate an electric current near the
boundary of a system in the presence of a static magnetic field. The magnitude
of this magnetization current, produced at zero temperature and in the absence
of matter, is proportional to a beta function associated with the
renormalization of the electric charge. Using first-principle lattice
simulations, we investigate how the breaking of the scale symmetry affects this
``scale magnetic effect'' near a Dirichlet boundary in scalar QED (Abelian
Higgs model). We demonstrate the interplay of the generated current with vortex
excitations both in symmetric (normal) and broken (superconducting) phases and
compare the results with the anomalous current produced in the conformal,
scale-invariant regime.Comment: 12 pages, 12 figure
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