Utsunomiya University

About: Utsunomiya University is a education organization based out in Utsunomiya, Japan. It is known for research contribution in the topics: Laser & Holography. The organization has 4139 authors who have published 6812 publications receiving 91975 citations. The organization is also known as: Utsunomiya daigaku.

Infrared Features of the Landau Gauge QCD

Abstract: The infrared features of Landau gauge QCD are studied by lattice simulation of $\ensuremath{\beta}{=6.0,16}^{4}{,24}^{4}{,32}^{4}$ and $\ensuremath{\beta}{=6.4,32}^{4}{,48}^{4}.$ We adopt two definitions of the gauge field, (1) U linear and (2) $\mathrm{log}U,$ and measured the gluon propagator and ghost propagator. The infrared singularity of the gluon propagator is less than that of the tree level result, but the gluon propagator at 0 momentum remains finite. The infrared singularity of the ghost propagator is stronger than the tree level. The QCD running coupling measured by using the gluon propagator and the ghost propagator has a maximum ${\ensuremath{\alpha}}_{s}(p)\ensuremath{\simeq}1$ at around $p=0.5$ GeV and decreases as p approaches 0. The data are analyzed with use of the formula of the principle of minimal sensitivity and the effective charge method, and by the contour-improved perturbation method, which suggest the necessity of the resummation of the perturbation series in the infrared region together with the existence of the infrared fixed point. The Kugo-Ojima parameter is about $\ensuremath{-}0.8$ in contrast with the theoretically expected value of $\ensuremath{-}1.$ The color off-diagonal part of the ghost propagator in the Landau gauge is consistent with zero, and its fluctuation can be parametrized as a $\mathrm{constant}{/(\mathrm{qa})}^{4}.$

Search for steady emission of 10-TeV gamma rays from the Crab Nebula, Cygnus X-3, and Hercules X-1 using the tibet air shower array

Abstract: The Tibet air shower array at an altitude of 4300 m has been in operation since January 1990. We have searched for continual emission of 10-TeV gamma rays from the Crab Nebula, Cygnus X-3 and Hercules X-1 during the period from June 1990 through January 1992. No dc excess is found from these three sources. Flux upper limits above 10 TeV are obtained to be 1.2\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ for the Crab Nebula, 1.1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ for Cygnus X-3, and 0.58\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ for Hercules X-1 at the 95% C.L. This is the first observation, with an air shower array, for these sources in the 10-TeV energy region.

Isotype-specific selection of high affinity memory B cells in nasal-associated lymphoid tissue.

Abstract: Mucosal immunoglobulin (Ig)A dominance has been proposed to be associated with preferential class switch recombination (CSR) to the IgA heavy chain constant region, Calpha. Here, we report that B cell activation in nasal-associated lymphoid tissue (NALT) upon stimulation with the hapten (4-hydroxy-3-nitrophenyl)acetyl (NP) coupled to chicken gamma globulin caused an anti-NP memory response dominated by high affinity IgA antibodies. In the response, however, NP-specific IgG(+) B cells expanded and sustained their number as a major population in germinal centers (GCs), supporting the view that CSR to IgG heavy chain constant region, Cgamma, operated efficiently in NALT. Both IgG(+) and IgA(+) GC B cells accumulated somatic mutations, indicative of affinity maturation to a similar extent, suggesting that both types of cell were equally selected by antigen. Despite the selection in GCs, high affinity NP-specific B cells were barely detected in the IgG memory compartment, whereas such cells dominated the IgA memory compartment. Taken together with the analysis of the V(H) gene clonotype in GC and memory B cells, we propose that NALT is equipped with a unique machinery providing IgA-specific enrichment of high affinity cells into the memory compartment, facilitating immunity with high affinity and noninflammatory secretory antibodies.

Discomfort glare for white LED light sources with different spatial arrangements

Abstract: Quantitative relations between discomfort glare evaluation and photometric quantities such as illuminance at the observer’s eye, average luminance of the source area, average luminance of the effective area and effective glare luminance for white LED sources having a variety of spatial luminance distributions have been investigated. Effective glare luminance, which is the sum of luminances in the luminaire area divided by the effective area, explains the scaling results of all sources in the same way. In addition, a new equation modified from the Commission Internationale de l'Eclairage Unified Glare Rating formula using the effective glare luminance showed a strong correlation with the scaling results. It is thus suggested that effective glare luminance is a useful index of discomfort glare for light sources having different spatial luminance distributions.