We evaluate the renormalization factors of the domain-wall fermion system with various improved gauge actions at the one-loop level. The renormalization factors are calculated for the quark wave function, quark mass, bilinear quark operators, and three-and four-quark operators in the modified minimal subtraction (MS) scheme with dimensional reduction as well as with the naive dimensional regularization. We also present detailed results in mean field improved perturbation theory.

We calculate the strange quark content of the nucleon hNj" ssjNi in 2 þ 1 -flavor lattice QCD. Chirally symmetric overlap fermion formulation is used to avoid the contamination from up and down quark contents due to an operator mixing between strange and light scalar operators, " ss and " uu þ " dd. At a lattice spacing a ¼ 0:112ð1Þ fm, we perform calculations at four values of degenerate up and down quark masses m ud , which cover a range of the pion mass M ' 300-540 MeV. We employ two different methods to calculate hNj" ssjNi. One is a direct method where we calculate hNj" ssjNi by directly inserting the " ss operator. The other is an indirect method where hNj" ssjNi is extracted from a derivative of the nucleon mass in terms of the strange quark mass. With these two methods we obtain consistent results for hNj" ssjNi with each other. Our best estimate f T s ¼ m s hNj" ssjNi=M N ¼ 0:009ð15Þ stat ð16Þ sys is in good agreement with our previous studies in two-flavor QCD.

We calculate the chiral condensate of QCD with 2, 2+1 and 3 flavors of sea quarks. Lattice QCD simulations are performed employing dynamical overlap fermions with up and down quark masses covering a range between 3 and 100 MeV. On L ∼ 1.8-1.9 fm lattices at a lattice spacing ∼ 0.11 fm, we calculate the eigenvalue spectrum of the overlap-Dirac operator. By matching the lattice data with the analytical prediction from chiral perturbation theory at the next-to-leading order, the chiral condensate in the massless limit of up and down quarks is determined.

A lattice study of the equation of state for pure SU͑3͒ gauge theory using a renormalization-group ͑RG͒ improved action is presented. The energy density and pressure are calculated on a 16 3 ϫ4 and a 32 3 ϫ8 lattice employing the integral method. Extrapolating the results to the continuum limit, we find the energy density and pressure to be in good agreement with those obtained with the standard plaquette action within the error of 3-4 %. ͓S0556-2821͑99͒07819-4͔

The low-lying eigenvalue spectrum of the QCD Dirac operator in the ǫ-regime is expected to match with that of chiral Random Matrix Theory (ChRMT). We study this correspondence for the case including sea quarks by performing two-flavor QCD simulations on the lattice. Using the overlap fermion formulation, which preserves exact chiral symmetry at finite lattice spacings, we push the sea quark mass down to ∼ 3 MeV on a 16 3 × 32 lattice at a lattice spacing a ≃ 0.11 fm.We compare the low-lying eigenvalue distributions and find a good agreement with the analytical predictions of ChRMT. By matching the lowest-lying eigenvalue we extract the chiral condensate, Σ MS (2 GeV) = (251 ± 7 ± 11 MeV) 3 , where errors represent statistical and higher order effects in the ǫ expansion. We also calculate the eigenvalue distributions on the lattices with heavier sea quarks at two lattice spacings. Although the ǫ expansion is not applied for those sea quarks, we find a reasonable agreement of the Dirac operator spectrum with ChRMT. The value of Σ, after extrapolating to the chiral limit, is consistent with the estimate in the ǫ-regime.

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X-ray holograms of two- or three-dimensionally distributed objects are recorded and reconstructed. The in-line holograms of a line-like object of a chemical fiber and a point-like object of red blood cell are made using AlKα radiation (8.34Å) from a two-stage fine focus X-ray generator. A magnified real image is reconstructed from the negative hologram using a He–Ne laser (6328Å). A lateral resolution of about 4 µm and a longitudinal resolution of about 4 mm are obtained in the two-step imaging process.

We find a static, anisotropic, non-supersymmetric generalization of the extreme supersymmetric domain walls of simple non-dilatonic supergravity theory. As opposed to the time-dependent isotropic non-and ultra-extreme domain walls, the anisotropic non-extreme wall has the same spatial topology as the extreme wall. The solution has naked singularities which vanish in the extreme limit. We use units so that κ ≡ 8πG = c = 1.