Amplification of Quantum Meson Modes in the Late Time of Chiral Phase Transition

It is shown that there exists a possibility of amplification of amplitudes of quantum pion modes with low momenta in the late time of chiral phase transition by using the Gaussian wave functional approximation in the O(4) linear sigma model. It is also shown that the amplification occurs in the mechanism of the resonance by forced oscillation as well as the parametric resonance induced by the small oscillation of the chiral condensate. These mechanisms are investigated in both the case of spatially homogeneous system and the spatially expanded system described by the Bjorken coordinate.Comment: 17 pages, 16 figure

The lipid composition and its alteration during the growth stage in pathogenic fungus, epidermophyton floccosum

Qualitative and quantitative changes of lipid components during the growth stages were studied in E. floccosum. The acyl group components of total lipids of Trichophyton rubrum and Microsporum cookei were also examined. The lipids of E. floccosum amounted to approximately 4% of the dry cell weight. Neutral lipids mainly consisted of triglycerides and sterols, and major polar lipids were phosphatidylcholine, phosphatidylethanolamine, and an unknown lipid X. The fatty acids in tryglycerides and phospholipids were palmitic, palmitoleic, stearic, oleic, and linoleic acids. The unknown polar lipid X which appeared between phosphatidylethanolamine and cardiolipin on thin layer chromatography plates contained no phosphorus. There was no significant change in the fatty acid components of E. floccosum and T. rubrum during the cell growth, whereas profound changes occurred in M. cookei. The sterol components of E. floccosum showed striking changes depending on the growth stage

Absence of the impurity-induced magnetic order in the electron-doped high-T_c_ cuprates Pr_0.86_LaCe_0.14_Cu_1-y_(Zn, Ni)_y_O_4_

Zero-field muon-spin-relaxation measurements have been carried out in order to investigate the Zn- and Ni-substitution effects on the Cu-spin dynamics in the electron-doped Pr_0.86_LaCe_0.14_Cu_1-y_(Zn, Ni)_y_O_4+\alpa-\delta_ with y = 0, 0.01, 0.02, 0.05 and different values of the reduced oxygen content \delta(\delta \le 0.09). For the samples with y = 0 and very small \delta values of \delta < 0.01, a muon-spin precession due to the formation of a long-range antiferromagnetic order has been observed at low temperatures below \~ 5 K. For the moderately oxygen-reduced samples of 0.01 \le \delta \le 0.09, on the contrary, no muon-spin precession has been observed and the temperature dependence of the spectra is similar to one another regardless of the y value. That is, no impurity-induced slowing down of the Cu-spin fluctuations has been detected, which is very different from the results of the hole-doped high-T_c_ cuprates. The reason is discussed.Comment: 13 pages, 2 figures, Proceedings of ISS2004 (to be published in Physica C