56 research outputs found
Anomalous-hydrodynamic analysis of charge-dependent elliptic flow in heavy-ion collisions
Anomalous hydrodynamics is a low-energy effective theory that captures
effects of quantum anomalies. We develop a numerical code of anomalous
hydrodynamics and apply it to dynamics of heavy-ion collisions, where anomalous
transports are expected to occur. This is the first attempt to perform fully
non-linear numerical simulations of anomalous hydrodynamics. We discuss
implications of the simulations for possible experimental observations of
anomalous transport effects. From analyses of the charge-dependent elliptic
flow parameters () as a function of the net charge asymmetry ,
we find that the linear dependence of on
the net charge asymmetry cannot be regarded as a robust signal of
anomalous transports, contrary to previous studies. We, however, find that the
intercept is sensitive to anomalous transport
effects.Comment: 11 pages, 3 figures, v
Does the chiral magnetic effect change the dynamic universality class in QCD?
In QCD matter under an external magnetic field, the chiral magnetic effect
(CME) leads to the collective gapless mode called the chiral magnetic wave
(CMW). Since dynamic universality class generally depends on low-energy gapless
modes, it is nontrivial whether the CME and the resulting CMW change that of
the second-order chiral phase transition in QCD. To address this question, we
study the critical dynamics near the chiral phase transition in massless
two-flavor QCD under an external magnetic field. By performing the dynamic
renormalization-group analysis within the epsilon expansion, we find that the
presence of the CME changes the dynamic universality class to that of model A.
We also show that the transport coefficient of the CME is not renormalized by
the critical fluctuations of the order parameter.Comment: 32 pages, 8 figures; v2: title and abstract modified, main results
changed, discussions substantially extended, published in JHE
New developments in relativistic magnetohydrodynamics
Relativistic magnetohydrodynamics (RMHD) provides an extremely useful
description of the low-energy long-wavelength phenomena in a variety of
physical systems from quark-gluon plasma in heavy-ion collisions to matters in
supernovas, compact stars, and early universe. We review the recent theoretical
progresses of RMHD, such as a formulation of RMHD from the perspective of
magnetic flux conservation using the entropy-current analysis, the
nonequilibrium statistical operator approach applied to quantum
electrodynamics, and the relativistic kinetic theory. We discuss how the
transport coefficients in RMHD are computed in kinetic theory and perturbative
quantum field theories. We also explore the collective modes and instabilities
in RMHD with a special emphasis on the role of chirality in a parity-odd
plasma. We also give some future prospects of RMHD, including the interaction
with spin hydrodynamics and the new kinetic framework with magnetic flux
conservation.Comment: 103 pages, 9 figures. Invited review for Symmetr
Effective field theory of time-translational symmetry breaking in nonequilibrium open system
We develop the effective field theoretical (EFT) approach to
time-translational symmetry breaking of nonequilibrium open systems based on
the Schwinger-Keldysh formalism. In the Schwinger-Keldysh formalism, all the
symmetries of the microscopic Lagrangian are doubled essentially because the
dynamical fields are doubled to describe the time-evolution along the
closed-time-path. The effective Lagrangian for open systems are then obtained
by coarse-graining the microscopic Schwinger-Keldysh Lagrangian. As a
consequence of coarse-graining procedure, there appear the noise and
dissipation effects, which explicitly break the doubled time-translational
symmetries into a diagonal one. We therefore need to incorporate this symmetry
structure to construct the EFT for Nambu-Goldstone bosons in symmetry broken
phases of open systems. Based on this observation together with the consistency
of the Schwinger-Keldysh action, we construct and study the general EFT for
time-translational symmetry breaking in particular, having in mind applications
to synchronization, time crystal, and cosmic inflation.Comment: 38 pages, 3 figure
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