Electromagnetic Spectrum from QGP Fluid

We calculate thermal photon and electron pair distribution from hot QCD matter produced in high energy heavy-ion collisions, based on a hydrodynamical model which is so tuned as to reproduce the recent experimental data at CERN SPS, and compare these electromagnetic spectra with experimental data given by CERN WA80 and CERES. We investigate mainly the effects of the off-shell properties of the source particles on the electromagnetic spectra.Comment: 5 pages, latex, 4 Postscript figures. A talk given at the International School on the Physics of Quark Gluon Plasma, June 3-6, 1997, Hiroshima, Japan. To be appeared in Prog. Theor. Phys. Supplemen

Anomalous low temperature state of CeOs4Sb12: Magnetic field and La-impurity study

Specific heat for single crystalline samples of Ce1-xLaxOs4Sb12 at zero-field and magnetic fields to 14 T is reported. Our results confirm enhanced value of the electronic specific heat coefficient in the paramagnetic state. They provide arguments for the intrinsic origin of the 1.1 K anomaly. This transition leads to opening of the gap at the Fermi surface. This low temperature state of CeOs4Sb12 is extremely sensitive to chemical impurities. 2% of La substituted for Ce suppresses the transition and reduces the electronic specific heat coefficient. The magnetic field response of the specific heat is also anomalous.Comment: 4 pages, 3 figure

Exotic Kondo-hole band resistivity and magnetoresistance of Ce1−x_{1-x}Lax_{x}Os4_4Sb12_{12} alloys

Electrical resistivity measurements of non-magnetic single-crystalline Ce$_{1-x}$La$_x$Os$_4$Sb$_{12}$ alloys, $x=0.02$ and 0.1, are reported for temperatures down to 20 mK and magnetic fields up to 18 T. At the lowest temperatures, the resistivity of Ce$_{0.98}$La$_{0.02}$Os$_4$Sb$_{12}$ has a Fermi-liquid-like temperature variation $\rho=\rho_0+A T^2$, but with negative $A$ in small fields. The resistivity has an unusually strong magnetic field dependence for a paramagnetic metal. The 20 mK resistivity increases by 75% between H=0 and 4 T and then decreases by 65% between 4 T and 18 T. Similarly, the $A$ coefficient increases with the field from -77 to 29$\mu\Omega$cmK$^{-2}$ between H=0 and 7 T and then decreases to 18$\mu\Omega$cmK$^{-2}$ for 18 T. This nontrivial temperature and field variation is attributed to the existence of a very narrow Kondo-hole band in the hybridization gap, which pins the Fermi energy. Due to disorder the Kondo-hole band has localized states close to the band edges. The resistivity for $x=0.1$ has a qualitatively similar behavior to that of $x=0.02$, but with a larger Kondo-hole band

Coverage dependent desorption dynamics of deuterium on Si(100) surfaces: Interpretation with a diffusion-promoted desorption model

We studied coverage dependence of time-of-flight (TOF) spectra of D2 molecules thermally desorbed from the D/Si(100) surface. The mean translational energies Et of desorbed D2 molecules were found to increase from 0.20±0.05 eV to 0.40±0.04 eV as the desorption coverage window was decreased from 1.0 MLD0.9 ML to 0.2 MLD0 ML, being consistent with the kinetics switch predicted in the interdimer mechanism. The measured TOF spectra were deconvoluted into 2H, 3H, and 4H components by a curve fitting method along the principle of detailed balance. As a result, it turned out that the desorption kinetics changes from the 4H to the 3H situation at high coverage above D = 0.9 ML, while the 2H desorption is dominant for a quite wide coverage region up to D = 0.8 ML. A dynamic desorption mechanism by which the desorption is promoted by D-atom diffusion to dangling bonds was proposed

Thermal Photon Emission from QGP fluid

We compare the numerical results of thermal photon distribution from the hot QCD matter produced by high energy nuclear collisions, based on hydrodynamical model, with the recent experimental data obtained by CERN WA80. Through the asymptotic value of the slope parameter of the transverse momentum distribution, we discuss the characteristic temperature of the QCD fluid.Comment: 16 pages, latex, 8 Postscript figure

Role of satellite cell-derived l-serine in the dorsal root ganglion in paclitaxel-induced painful peripheral neuropathy

Paclitaxel is one of the most commonly used antineoplastic drugs for the treatment of solid tumors. Unfortunately, its use is often associated with dose-limiting painful peripheral neuropathy and subsequent neuropathic pain that is resistant to standard analgesics. However, there are few clinically available drugs or drug classes for the treatment of paclitaxel-induced neuropathy due to a lack of information regarding the mechanisms responsible for it. In this study, we examined the involvement of L-serine in paclitaxel-induced hyperalgesia/allodynia and decrease in sensory nerve conduction velocity (SNCV). We used a preclinical rat model of paclitaxel-induced painful peripheral neuropathy. Response to von Frey filaments, SNCV, 3-phosphoglycerate dehydrogenase (3PGDH) expression, and L-serine concentration were examined. Effects of L-serine administration were also investigated. Paclitaxel treatment induced mechanical allodynia/hyperalgesia and reduction of SNCV. Paclitaxel also decreased the L-serine concentration in the dorsal root ganglion (DRG) but not in the sciatic nerve or spinal cord. In addition, paclitaxel decreased expression of 3PGDH, a biosynthetic enzyme of L-serine, in the DRG. Immunohistochemistry showed that 3PGDH was localized in satellite cells but not in neurons in the DRG. Intraperitoneal administration of L-serine improved both paclitaxel-induced mechanical allodynia/hyperalgesia and the reduction of SNCV. These results suggest that satellite cell-derived L-serine in the DRG plays an important role in paclitaxel-induced painful peripheral neuropathy. These findings may lead to novel strategies for the treatment of paclitaxel-induced painful peripheral neuropathy.ArticleNEUROSCIENCE. 174(0):190-199 (2011)journal articl

A Massive Jet Ejection Event from the Microquasar SS 433 Accompanying Rapid X-Ray Variability

Microquasars occasionally exhibit massive jet ejections which are distinct from the continuous or quasi-continuous weak jet ejections. Because those massive jet ejections are rare and short events, they have hardly been observed in X-ray so far. In this paper, the first X-ray observation of a massive jet ejection from the microquasar SS 433 with the Rossi X-ray Timing Explorer (RXTE) is reported. SS 433 undergoing a massive ejection event shows a variety of new phenomena including a QPO-like feature near 0.1 Hz, rapid time variability, and shot-like activities. The shot-like activity may be caused by the formation of a small plasma bullet. A massive jet may be consist of thousands of those plasma bullets ejected from the binary system. The size, mass, internal energy, and kinetic energy of the bullets and the massive jet are estimated.Comment: 21 pages including 5 figures, submitted to Ap