5,304 research outputs found
Dynamical Density Fluctuations around QCD Critical Point Based on Dissipative Relativistic Fluid Dynamics-possible fate of Mach cone at the critical point-
The purpose of this paper is twofold. Firstly, we study the dynamical density
fluctuations around the critical point(CP) of Quantum Chromodynamics(QCD) using
dissipative relativistic fluid dynamics in which the coupling of the density
fluctuations to those of other conserved quantities is taken into account. We
show that the sound mode which is directly coupled to the mechanical density
fluctuation is attenuated and in turn the thermal mode becomes the genuine soft
mode at the QCD CP. We give a speculation on the possible fate of a Mach cone
in the vicinity of the QCD CP as a signal of the existence of the CP on the
basis of the above findings. Secondly, we clarify that the so called
first-order relativistic fluid dynamic equations have generically no problem to
describe fluid dynamic phenomena with long wave lengths contrary to a naive
suspect whereas even Israel-Stewart equation, a popular second-order equation,
may not describe the hydrodynamic mode in general depending on the value of the
relaxation time.Comment: 29pages, 4figures; accepted version for publication in Prog. Theor.
Phys. Introduction and Sec.3 are somewhat modified to make clearer the
purpose of this paper and the discussions on the critical behaviors,
respectively. A few references are added. The conclusions are not changed at
al
Phase Separation in A-site Ordered Perovskite Manganite LaBaMnO Probed by La and Mn NMR
La- and Mn-NMR spectra demonstrate that the ground state of
the A-site ordered perovskite manganite LaBaMnO is a spatial mixture of
the ferromagnetic (FM) and antiferromagnetic (AFI(CE)) regions, which are
assigned to the metallic and the insulating charge ordered state, respectively.
This exotic coexisting state appears below 200 K via a first-order-like
formation of the AFI(CE) state inside the FM one. Mn spin-spin relaxation rate
indicates that the FM region coexisting with the AFI(CE) one in LaBaMnO
is identical to the bulk FM phase of the disordered form
LaBaMnO in spite of the absence of A-site disorder. This
suggests mesoscopic rather than nanoscopic nature of FM region in
LaBaMnO\@.Comment: 4 pages, 4 figures, to be published in Phys. Rev. Let
Interplay between different states in heavy fermion physics
Calorimetry experiments under high pressure were used to clarify the
interplay between different states such as superconductivity and
antiferromagnetism in CeRhIn5, spin density wave and large moment
antiferromagnetism in URu2Si2. Evidences are given on the re-entrance of
antiferromagnetism under magnetic field in the superconducting phase of CeRhIn5
up to pc = 2.5 GPa where the Neel temperature will collapse in the absence of
superconductivity. For URu2Si2 measurements up to 10 GPa support strongly the
coexistence of spin density wave and large moment antiferromagnetism at high
pressures.Comment: 6 pages, 9 figures, presented at ICM200
Prevalence of bacteriophage-associated super-antigen genes in Streptococcus pyogenes isolated from pediatric patients in Japan
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