Negative-Parity Baryons in Quenched Anisotropic Lattice QCD

We study negative-parity baryon spectra in quenched anisotropic lattice QCD. The negative-parity baryons are measured as the parity partner of the ground-state baryons. In addition to the flavor octet and decuplet baryons, we pay much attention to the flavor-singlet negative-parity baryon as a three-quark state and compare it with the Lambda(1405) baryon. Numerical results of the flavor octet and decuplet negative-parity baryon masses are close to experimental values of lowest-lying negative-parity baryons, while the flavor-singlet baryon is much heavier than Lambda(1405). This indicates that the Lambda(1405) would be a multi-quark state such as the N-Kbar molecule rather than the flavor-singlet 3 quark state.Comment: 4 pages, 4 figs. Talk given at 16th International Conference on Particles and Nuclei (PANIC 02), Osaka, Japan, 30 Sep - 4 Oct 200

Pion electromagnetic form-factor with domain wall fermions

Motivated by recent measurements at J-Lab, the pion electromagnetic form-factor is investigated with quenched domain wall fermions and a renormalization group improved gauge action called DBW2. We see that quark mass dependence of the form-factor with finite momentum transfers is rather small.Comment: Lattice2003(matrix), 3 pages, 5 figure

Chiral thermodynamics of dense hadronic matter

We discuss phases of hot and dense hadronic matter using chiral Lagrangians. A two-flavored parity doublet model constrained by the nuclear matter ground state predicts chiral symmetry restoration. The model thermodynamics is shown within the mean field approximation. A field-theoretical constraint on possible phases from the anomaly matching is also discussed.Comment: 8 pages, 2 figures, to appear in the proceedings of 6th International Workshop on Critical Point and Onset of Deconfinement (CPOD), 23-29 August 2010 at Joint Institute for Nuclear Research, Dubna, Russi

cDNA display: a novel screening method for functional disulfide-rich peptides by solid-phase synthesis and stabilization of mRNA–protein fusions

We report a robust display technology for the screening of disulfide-rich peptides, based on cDNA–protein fusions, by developing a novel and versatile puromycin-linker DNA. This linker comprises four major portions: a ‘ligation site’ for T4 RNA ligase, a ‘biotin site’ for solid-phase handling, a ‘reverse transcription primer site’ for the efficient and rapid conversion from an unstable mRNA–protein fusion (mRNA display) to a stable mRNA/cDNA–protein fusion (cDNA display) whose cDNA is covalently linked to its encoded protein and a ‘restriction enzyme site’ for the release of a complex from the solid support. This enables not only stabilizing mRNA–protein fusions but also promoting both protein folding and disulfide shuffling reactions. We evaluated the performance of cDNA display in different model systems and demonstrated an enrichment efficiency of 20-fold per selection round. Selection of a 32-residue random library against interleukin-6 receptor generated novel peptides containing multiple disulfide bonds with a unique linkage for its function. The peptides were found to bind with the target in the low nanomolar range. These results show the suitability of our method for in vitro selections of disulfide-rich proteins and other potential applications

Measurement of radon concentrations at Super-Kamiokande

Radioactivity from radon is a major background for observing solar neutrinos at Super-Kamiokande. In this paper, we describe the measurement of radon concentrations at Super-Kamiokande, the method of radon reduction, and the radon monitoring system. The measurement shows that the current low-energy event rate between 5.0 MeV and 6.5 MeV implies a radon concentration in the Super-Kamiokande water of less than 1.4 mBq/m$^3$.Comment: 11 pages, 4 figure

Observation of the east-west anisotropy of the atmospheric neutrino flux

The east-west anisotropy, caused by the deflection of primary cosmic rays in the Earth's magnetic field, is observed for the first time in the flux of atmospheric neutrinos. Using a 45 kt-year exposure of the Super-Kamiokande detector, 552 e-like and 633 mu-like horizontally-going events are selected in the momentum range between 400 and 3000 MeV/c. The azimuthal distribution of e-like and mu-like events agrees with the expectation from atmospheric neutrino flux calculations that account for the geomagnetic field, verifying that the geomagnetic field effects in the production of atmospheric neutrinos in the GeV energy range are well understood.Comment: 8 pages,3 figures revtex, submitted to PR