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We studied the band structure of NdFeAs$_{1-x}$P$_{x}$O$_{0.9}$F$_{0.1}$ ($x$ = 0, 0.2, 0.4 and 0.6) using angle-resolved photoemission spectroscopy (ARPES) measurements. Two of the hole bands, ${\alpha}_1$ $(d_{xz})$ and ${\alpha}_3$ $(d_{z^2})$, were observed at the Brillouin zone center in the $P$-polarized light configuration, while the other two hole bands, ${\alpha}_2$ $(d_{yz})$ and ${\gamma}$ $(d_{xy})$, were observed in the $S$-polarized alternative. The observed ${\gamma}$ band shifts downwards as $x$ increases, which is consistent with the theoretical prediction for the change in bond angle of As/P-Fe-As/P. Furthermore, a small amount of the $d_{xy}$ orbital component was observed at the same binding energy as that of the top of the ${\alpha}_1$ band, thus indicating the band reconstruction of the originally degenerate ${\alpha}_1$ and ${\alpha}_2$ $(d_{xz}/d_{yz})$ bands by the unoccupied $d_{xy}$ band. The change in the energy level of the ${\alpha}_1$ band top with $d_{xy}$ orbital character is accompanied by a $T_{c}$ upturn at $0.2 < x < 0.4$. The $T_{c}$ continues to increase as the ${\alpha}_1$ band shifts downward, crossing the Fermi level. The incipient band with the $d_{xy}$ orbital character on its top could be an important ingredient for high $T_{c}$ 1111-type iron-based superconductors., Comment: 10 pages, 7 figures, Accepted for publication in Phys. Rev. B

A novel secure communication network with quantum key distribution in a metropolitan area is reported. Different QKD schemes are integrated to demonstrate secure TV conferencing over a distance of 45km, stable long-term operation, and application to secure mobile phones., Comment: 21 pages, 19 figures

We report on the experimental demonstration of a source of hybrid entanglement pairs between two different degrees of freedom, a 1550 nm time-bin qubit and an 810 nm polarization qubit. The polarization qubit at 810 nm is transformed by an asymmetric Mach-Zehnder interferometer consisted of a Glan laser prism and a polarization-maintaining fiber. We obtained visibilities of 95.8% and 88% along Z-Z and X-X axes on the Poincare sphere, respectively with a coincidence count rate of more than 800 c/s after entanglement format transformation. These values are well above the threshold of 70.7% needed to violate a Bell inequality and allow distilling a secure key in the quantum key distribution., Comment: 11pages, 4 figures

Crab cavities have been installed in the KEKB B--Factory rings to compensate the crossing angle at the collision point and thus increase luminosity. The beam operation with crab crossing has been done since February 2007. This is the first experience with such cavities in colliders or storage rings. The crab cavities have been working without serious issues. While higher specific luminosity than the geometrical gain has been achieved, further study is necessary and under way to reach the prediction of simulation., Comment: Submitted to Particle Accelerator Conference 2007, MOZAKI01, Albuquerque

We propose a new hadronization mechanism, jet-fluid string (JFS) formation and decay, to understand observables in intermediate to high-$p_{T}$ regions comprehensively. In the JFS model, hard partons produced in jet lose their energy in traversing the QGP fluid, which is described by fully three-dimensional hydrodynamic simulations. When a jet parton escapes from the QGP fluid, it picks up a partner parton from a fluid and forms a color singlet string, then it decays to hadrons. We find that high-$p_T$ $v_2$ values in JFS are about two times larger than in the independent fragmentation model., Comment: 6 pages, 2 figures; Proceeding for poster sessions at Quark Matter 2006, Shanghai, China, 14-20 November 2006; to appear in Int. J. of Mod. Phys. E

Single particle spectra as well as elliptic flow in Cu+Cu collisions at $\sqrt{s_{NN}}=200$ GeV are investigated within a hadronic cascade model and an ideal hydrodynamic model. Pseudorapidity distribution and transverse momentum spectra for charged hadrons are surprisingly comparable between these two models. However, a large deviation is predicted for the elliptic flow. The forthcoming experimental data will clarify the transport and thermalization aspects of matter produced in Cu+Cu collisions., Comment: 5 pages, 5 figures; Version to appear in Phys.Rev.C

An Alvaretz-type DTL, to accelerate the H- ion beam from 3 to 50 MeV, is being constructed as the injector for the JAERI/KEK Joint Project. The following components of the DTL have been developed: (1) a cylindrical tank, made by copper electroforming; (2) rf contactors; (3) a pulse-excited quadrupole magnet with a hollow coil made by copper electroforming; (4) a switching-regulator-type pulsed-power supply for the quadrupole magnet. High-power tests of the components have been conducted using a short-model tank. Moreover a breakdown experiment of the copper electrodes has been carried out in order to study the properties of several kinds of copper materials.

Quadrupole electromagnets have been developed with a hollow coil produced using an improved periodic reverse electroforming. These will be installed in each of the drift tubes of the DTL (324 MHz) as part of the JAERI/KEK Joint Project at the high-intensity proton accelerator facility. Measurements of the magnets' properties were found to be consistent with computer-calculated estimated. The details of the design, the fabrication process, and the measurement results for the quadrupole magnet are described.

Experimental apparatus and measurement technique are described for precision absorption measurements in sodium - noble gas mixtures. The absolute absorption coefficient is measured in the wavelength range from 425 nm to 760 nm with 2% uncertainty and spectral resolution of 0.02 nm. The precision is achieved by using a specially designed absorption cell with an accurately defined absorption path length, low noise CCD detector and double-beam absorption measurement scheme. The experimental set-up and the cell design details are given. Measurements of sodium atomic number density with 5% uncertainty complement absorption coefficient measurements and allow derivation of the reduced absorption coefficients for certain spectral features. The sodium atomic number density is measured using the anomalous dispersion method. The accuracy of this method is improved by employing a least-squares fit to the interference image recorded with CCD detector and the details of this technique are given. The measurements are aimed at stringent testing of theoretical calculations and improving the values of molecular parameters used in calculations., Comment: 9 figures in eps format