U_A(1) Anomaly in Hot and Dense QCD and the Critical Surface

We discuss the chiral phase transition in hot and dense QCD with three light flavors. Inspired by the well known fact that the U_A(1) anomaly could induce first order phase transitions, we study the effect of the possible restoration of the U_A(1) symmetry at finite density. In particular, we explore the link between the U_A(1) restoration and the recent lattice QCD results of de Forcrand and Philipsen, in which the first order phase transition region near zero chemical potential (mu) shrinks in the quark mass and mu space when mu is increased. Starting from the Ginzburg-Landau theory for general discussions, we then use the Nambu--Jona-Lasinio model for quantitative studies. With the partial U_A(1) restoration modeled by the density dependent 't Hooft interaction, we fit the shrinking of the critical surface found in de Forcrand and Philipsen's lattice calculation at low mu. At higher mu, the critical surface might shrink or expand, depending on the scenarios. This raises the possibility that despite the shrinking of the critical surface at lower mu, the QCD critical end point might still exist due to the expansion at higher mu. In this case, very high precision lattice data will be needed to detect the back-bending of the critical surface with the currently available analytic continuation or Taylor expansion approaches. Lattice computations could, however, test whether the U_A(1) restoration is responsible for the shrinking of the critical surface by computing eta' mass or the topological susceptibility at small mu.Comment: 8 pages, 5 figure

Gauge dynamics in the PNJL model: Color neutrality and Casimir scaling

We discuss a gauge-invariant prescription to take the mean-field approximation self-consistently in the PNJL model (Nambu--Jona-Lasinio model with the Polyakov loop). We first address the problem of non-vanishing color density in normal quark matter, which is an artifact arising from gauge-fixed treatment of the Polyakov loop mean-fields. We then confirm that the gauge average incorporated in our prescription resolves this problem and ensures color neutrality. We point out that the proposed method has an advantage in computing the expectation value of any function of the Polyakov loop matrix. We discuss the Casimir scaling as an immediate application of the method.Comment: 13 pages, 5 eps figures; v2: published versio

High-Gain Power Recycling of a Fabry Perot Michelson Interferometer for a Gravitational-Wave Antenna

Power recycling was implemented on a fully suspended prototype interferometer with arm lengths of 20 m. A wave-front-sensing technique for alignment control of the suspended mirrors was also implemented, which allowed for several hours of stable operation. A power-recycling gain of greater than 12 was achieved, a significant increase over the highest gain in a suspended mirror Fabry Perot Michelson interferometer reported to date

Studies on sinter deposits in Misasa radioactive hot springs (2nd report)

Qualitative and quantitative analysis of sinter deposits in a distributing pipe used for seventeen years (Sample No.1) and adhere to bathtub wall for eleven years (Sample No.2 and Sample No.3) in Misasa radioactive hot springs were investigated. The results were as follows ; (1) The color of deposits of Sample No.1 and Sample No.2 was black and the color of deposits of Sample No.3 was white. The metal elements in these deposits were qualitative analysed by spectraspan plasma emission spectrophotometry (SPES) and by fluorescent X-ray spectrometry. Following elements were detected, in Sample No.1 : Na, Mg, Al, K, Ca, Mn, Fe, Cu, As, Sr, Ba, Mo, and Pb, in Sample No.2 : Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe, Cu, Zn, As, Sr, Ba, Pb and Cl and in Sample No.3 : Na, Mg, Al, Si, K, Ca, Mn, Fe, Cu, Zn, As, Rb, Sr, Mo, Ba, S, and Cl, (2) The metal elements in these deposits were quantitative analysed by SPES, atomic absorption spectrophotometry and emission spectrophometry. Following elements were determined, in Sample No.1 ; Mn : 411.6, Fe : 65.7, Ba : 20.0, Ca : 11.9, Na : 5.7, Cu : 4.5, K : 4.2, Sr : 2.9, Zn : 2.6, Mg : 1.4, in Sample No.2 ; Mn : 248.2, Fe : 28.5, Ba : 15.6, Ca : 25.0, Mg : 10.5, Na : 9.3, Cu : 5.4, K : 4.9, Sr: 7.4, Zn : 3.3, and in Sample No.3 ; Ca : 275.2, Sr : 32.4, Mg: 12.4, Na: 18.7, K: 5.0, Mn: 1.7 and Fe: 0.6mg per gram. The main components of these deposits were manganese compounds (Sample No.1 and Sample No.2) and calcium compounds (Sample No.3). Qualitative and quantitative analysis of barium in sinter deposits of Misasa spa was done by authers for the first time. (3) Radioactivity in these deposits were observed by autoradiography. Among the radioactive elements, concentration of radium were 3.41×10(-8) Ci/g (Sample No.1), 4.70×10(-9) Ci/g (Sample No.2) anp 2.36×10(-11) Ci/g (Sample No.3), respectively

Studies on sinter deposit Misasa radioactive hot springs

Sinter deposit in a distributing pipe used for about fifteen years in Misasa radioactive hot springs was investigated. The results were as follows; 1. The metal elements in this deposit were quaIi. tatively analysed by spectraspan plasma emission spectrophotometry (SPES), by fluorescent X-ray spectrometry, and following elements were detected; B, Na, Mg, AI, K, Ca, Mn, Fe, Cu, Zn, As, Sr, Ba and Pb. 2. The metal elements in this deposit were quantatively analysed by SPES and atomic absorption spectrophotometry, and following elements were determined; Fe : 508.7, As: 26.40, Ca: 7.85, Mn : 2.00, Al : 1.80, Na: 1.60, Zn: 1.33, K: 0.80, Cu: 0.67, Sr: 0.47, Mg: 0.35, Ba: 0.33 and B : 0.30 mg per gram. The color of this deposit was red brown, and the main component was ferric oxide. 3. Radioactive elements in this deposit were detected by autoradiography and radioluxography. Among the radioactive elements, concentration of radium was 320.5×10(-12)g/g (313.0×10(-12)Ci/g)

近赤外線分光法を用いた局所酸素飽和度による熱傷深度測定の検討

The burn severity depends on the wound depth and area affected. Hitherto burn depth has been judged mainly by visual observation, although concerns have been raised about its validity. The regional tissue blood flow (rTBF) measured by laser Doppler imaging (LDI) in damaged tissue correlates with the depth. However, very few reports are available on the significance of the regional tissue oxygen saturation (rSO2) as an indicator of burn depth. We investigated whether rSO2 by Near-infrared spectroscopy (NIRS) in burn injuries correlates with rTBF by LDI, which would facilitate quantification of the severity of the tissue damage. Methods: We measured rTBF and rSO2 in 50 lesions from 14 patients of burn injury within 24 hours after injury. The correlation between rTBF and rSO2 was evaluated by Spearman rank correlation analysis. Results: The rSO2 (%; range, 52-82) by NIRS and the rTBF (perfusion unit; range, 61-704) by LDI in burn lesions were positively correlated (r=0.755, p<0.001). This statistically positive correlation still remained significant (r=0.678, p<0.001) after the rSO2 values were standardized. Conclusion: This study suggests that NIRS determination of rSO2 in burn injuries shows promise as a reliable and quick method to estimate the depth of burn lesion.博士（医学）・乙第1343号・平成26年7月22日© 2014 Seki Tadahiko et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Investigation of meson masses for real and imaginary chemical potential

We investigate chemical-potential ($\mu$) and temperature ($T$) dependence of scalar and pseudo-scalar meson masses for both real and imaginary $\mu$, using the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model with three-flavor quarks. A three-flavor phase diagram is drawn in $\mu^2$-$T$ plane where positive (negative) $\mu^2$ corresponds to positive (imaginary) $\mu$. A critical surface is plotted as a function of light- and strange-quark current mass and $\mu^2$. We show that $\mu$-dependence of the six-quark Kobayashi-Maskawa-'t Hooft (KMT) determinant interaction originated in $U_\mathrm{A}(1)$ anomaly can be determined from lattice QCD data on $\eta'$ meson mass around $\mu =0$ and $\mu = i \pi T/3$ with $T$ slightly above the critical temperature at $\mu=0$ where the chiral symmetry is restored at $\mu=0$ but broken at $\mu =i \pi T/3$, if it is measured in future.Comment: 13 pages, 12 figure