5,724 research outputs found
Overdamping Phenomena near the Critical Point in O() Model
We consider the dynamic critical behavior of the propagating mode for the
order parameter fluctuation of the O() Ginzburg-Landau theory, involving the
canonical momentum as a degree of freedom. We reexamine the renormalization
group analysis of the Langevin equation for the propagating mode. We find the
fixed point for the propagating mode as well as that for the diffusive one, the
former of which is unstable to the latter. This indicates that the propagating
mode becomes overdamped near the critical point. We thus can have a sufficient
understanding of the phonon mode in the structural phase transition of solids.
We also discuss the implication for the chiral phase transition.Comment: 5 pages, 1 figure;v3 modification for correcting a misleading
description, conclusion unchange
Derivation of Covariant Dissipative Fluid Dynamics in the Renormalization-group Method
We derive generic relativistic hydrodynamical equations with dissipative
effects from the underlying Boltzmann equation in a mechanical and systematic
way on the basis of so called the renormalization-group (RG) method. A
macroscopic frame vector is introduced to specify the frame on which the
macroscopic dynamics is described. Our method is so mechanical with only few
ansatz that our method give a microscopic foundation of the available
hydrodynamical equations, and also can be applied to make a reduction of the
kinetic equations other than the simple Boltzmann equation.Comment: Serious typos and a minor one are corrected in p.6 and 7, and in p.1,
respectivel
Phase diagram at finite temperature and quark density in the strong coupling region of lattice QCD for color SU(3)
We study the phase diagram of quark matter at finite temperature (T) and
chemical potential (mu) in the strong coupling region of lattice QCD for color
SU(3). Baryon has effects to extend the hadron phase to a larger mu direction
relative to Tc at low temperatures in the strong coupling limit. With the 1/g^2
corrections, Tc is found to decrease rapidly as g decreases, and the shape of
the phase diagram becomes closer to that expected in the real world.Comment: 4 pages, 4 figures. To appear in the proceedings of the 19th
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions,
Shanghai, China, Nov. 14-20, 2006 (Quark Matter 2006
Brown-Rho Scaling in the Strong Coupling Lattice QCD
We examine the Brown-Rho scaling for meson masses in the strong coupling
limit of lattice QCD with one species of staggered fermion. Analytical
expression of meson masses is derived at finite temperature and chemical
potential. We find that meson masses are approximately proportional to the
equilibrium value of the chiral condensate, which evolves as a function of
temperature and chemical potential.Comment: Prepared for Chiral Symmetry in Hadron and Nuclear Physics
(Chiral07), Nov. 13-16, 2007, Osaka, Japa
Multi-phases in gauge theories on non-simply connected spaces
It is pointed out that phase structures of gauge theories compactified on
non-simply connected spaces are not trivial. As a demonstration, an SU(2) gauge
model on is studied and is shown to possess three phases:
Hosotani, Higgs and coexisting phases. The critical radius and the order of the
phase transitions are explicitly determined. A general discussion about phase
structures for small and large scales of compactified spaces is given. The
appearance of phase transitions suggests a GUT scenario in which the gauge
hierarchy problem is replaced by a dynamical problem of how to stabilize a
radius of a compactified space in close vicinity to a critical radius.Comment: 12 pages, 1 figur
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