Measurement of B(Ds{+}-->mu+nu(mu))

We present a measurement of the branching fraction B(D{s}{+}-->mu{+}nu{mu}) using a 548 fb{-1} data sample collected by the Belle experiment at the KEKB e{+}e{-} collider. The D{s} momentum is determined by reconstruction of the system recoiling against DKgammaX in events of the type e{+}e{-}-->D{s}{*}DKX, D{s}{*}-->D{s}gamma, where X represents additional pions or photons from fragmentation. This full-reconstruction method provides high resolution in the neutrino momentum and thus good background separation, equivalent to that achieved by experiments at the tau-charm factories. We obtain the branching fraction B(D{s}{+}-->mu{+}nu{mu})=[6.44+/-0.76(stat)+/-0.57(syst)]x10{-3}, implying a D{s} decay constant of f{D{s}}=[275+/-16(stat)+/-12(syst)] MeV.     

Production of new charmoniumlike states in e+e- -->J/psiD*D[over](*) at sqrt[s] approximately 10.6 GeV

We report a study of the processes e+e- -->J/psiD*D[over](*). In J/psiD*D[over]* we observe a significant enhancement in the D*D[over]* invariant mass spectrum, which we interpret as a new charmoniumlike state and denote X(4160). The X(4160) parameters are M=(4156(-20)+25+/-15) MeV/c2 and Gamma=(139(-61)+111+/-21) MeV. We also report a new measurement of the X(3940) mass and width: M=(3942(-6)+7+/-6) MeV/c2 and Gamma=(37(-15)+26+/-8) MeV. The analysis is based on a 693 fb(-1) data sample recorded near the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric-energy collider.     

Observation of a near-threshold enhancement in the e+e- -->Lambda+_(c)Lambda-_(c) cross section using initial-state radiation

We report a measurement of the exclusive e+ e- -->Lambda+_(c)Lambda-_(c) cross section as a function of center-of-mass energy near the Lambda+_(c)Lambda-_(c) threshold. A clear peak with a significance of 8.2sigma is observed in the Lambda+_(c)Lambda-_(c) invariant mass distribution just above threshold. With an assumption of a resonance origin for the observed peak, a mass and width of M=[4634 (+8)_(-7)(stat)(+5)_(-8)(syst)] MeV/c(2) and Gamma_(tot)=[92 (+40)_(-24)(stat)(+10)_(-21)(syst)] MeV are determined. The analysis is based on a study of events with initial-state-radiation photons in a data sample collected with the Belle detector at the Upsilon(4S) resonance and nearby continuum with an integrated luminosity of 695 fb(-1) at the KEKB asymmetric-energy e+ e- collider.     

Development of soft X-ray multilayer laminar-type plane gratings and varied-line-spacing spherical grating for flat-field spectrograph in the 1–8 keV region

W/C and Co/SiO₂ multilayer laminar-type holographic plane gratings (groove density 1/σ = 1200 lines/mm) in the 1–8 keV region are developed. For the Co/SiO₂ grating the diffraction efficiencies of 0.41 and 0.47 at 4 and 6 keV, respectively, and for the W/C grating 0.38 at 8 keV are observed. Taking advantage of the outstanding high diffraction efficiencies into practical soft X-ray spectrographs a Mo/SiO₂ multilayer varied-line-spacing (VLS) laminar-type spherical grating (1/σ = 2400 lines/mm) is also developed for use with a flat field spectrograph in the region of 1.7 keV. For the Mo/SiO₂ multilayer grating the diffraction efficiencies of 0.05–0.20 at 0.9–1.8 keV are observed. The FWHMs of the measured line profiles of Hf-Mα₁(1644.6 eV), Si-Kα₁(1740.0 eV), and W-Mα₁ (1775.4 eV) are 13.7 eV, 8.0 eV, and 8.7 eV, respectively.     

A Synthesis of an Isoindole Derivative

Isoindole or 1H-isoindole, where there is the possibility of tautoinerism, is too unstable to be isolated, and its existence is ascertained only by Diels-Alder addition products with maleic anhydride and N-phenylmaleinimide.¹⁾ Moreover, the systematic preparations of isoindole derivatives have not been confirmed.²⁾ However, several successful isoindole syntheses have been realized from ortho-disubstituted benzene derivatives. For instance,³⁾ catalytic reduction over Raney nickel of o-cyanobenzophenone gave 1-phenylisoindole, accompanied by the oxidative coupling product. We wish to report now a synthesis of an isoindole derivative (2) by the dimerization of o-tolunitrile and several reactions of the compound (2), and the physical data were also reported.     

Snow melting with low temperature solidification aqueous solution

This paper is concerned with the melting of snow layer by showering the Calcium Chloride aqueous solution at the temperature of 0°C to obtain the effects of initial concentration of the solution, showering amount of the solution and density of packed snow sample on melting of snow, in the short period after snow melting being initiated. The rate of internal melting in the snow layer is great compared with that of the surface melting. As melting time passes, the temperature of snow layer gradually decreases to the solid-liquid equilibrium temperature. This phenomenon corresponds to the solidification temperature drop. The temperature distribution in the normal direction in snow layer becomes uniform at the equilibrium temperature. Therefore, after this period the major part of melt amount is surface melting only. From this fact the typical melting behaviour may be mainly induced by the effect of chemical reaction. It is demonstrated that the results obtained in this experiment could give an useful basic information for accelerating the melting of snow layer.

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Schnee schmelzen mit einer wäßrigen Lösung niedriger Erstarrungstemperatur

Zusammenfassung Der Aufsatz behandelt das Schmelzen einer Schneeschicht mittels Übersprühen mit einer wäßrigen Kalziumchloridlösung einer Temperatur von 0°C mit dem Ziel, die Einflüsse unterschiedlicher Anfangskonzentrationen der Lösung, verschiedener Sprühmengen und unterschiedlich dichte Packung des Schnees in der Anfangsphase des Aufschmelzens zu untersuchen. Die Schmelzrate im Inneren der Schneeschicht ist groß, verglichen mit der auf der Schneeoberfläche. Im Verlauf der Aufschmelzzeit sinkt die Temperatur der Schneeschicht langsam auf die fest-flüssige Gleichgewichtstemperatur. Dies entspricht der Temperaturabsenkung bei der Erstarrung. Die Temperaturverteilung senkrecht zur Schneeschicht vergleichmäßigt sich bei der Gleichgewichtstemperatur. Deshalb resultiert nach dieser Anfangsperiode die Schmelzmasse hauptsächlich nur aus dem Aufschmelzen an der Oberfläche. Aus diesen Tatsachen kann auf ein Schmelzverhalten in der Anfangsperiode geschlossen werden, das hauptsächlich durch die chemische Reaktion bestimmt ist. Es wird gezeigt, daß die in dem vorgestellten Experiment ermittelten Ergebnisse nützliche, grundlegende Hinweise für die Beschleunigung des Abschmelzens einer Schneeschicht geben können.

     

Simultaneous acquisition of color and distance information by LiDAR with RGB visible laser diodes

We propose colors light detection and ranging (LiDAR) using visible laser diodes (LD) of red, green, and blue (RGB) colors to identify colors as well as obtain position information of surrounding objects. To verify the principle, we performed round-trip time-of-flight (TOF) measurements by irradiating a target of different colors with pulsed light from a LD of RGB colors. It is clarified that accurate distance measurements of up to 12 m can be realized in any RGB LD, and the received signal in each LD has different intensity characteristics depending on the target color. From a judgment table created from reception intensity characteristics for three types of LD and seven types of color target, the color of each target is successfully identified.

     

Monitoring the Discontinuous Dodecamer–Icosamer Transition of a Calix[4]arene-Derived Surfactant by Time-Resolved Small-Angle X-ray Scattering

Calix[4]arene-derived surfactants form monodisperse micelles with a well-defined aggregation number (N_agg) of 4, 6, 8, 12, or 20, corresponding to the Platonic solids. This feature is in strong contrast to conventional micelles. In this study, a transition from a dodecamer (N_agg=12) to an icosamer (N_agg=20) was induced by a rapid increase in the NaCl concentration (C_NaCl) using a stopped-flow device and directly observed by time-resolved small-angle X-ray scattering. The N_agg remained unchanged during the first 60 s after the increase in C_NaCl , and then abruptly increased to 20. This feature resembles phase transitions in supersaturated or supercooled states, or highly cooperative phenomena. We surmise that this finding may be due to the fact that only a few N_agg values are thermodynamically allowed when N_agg is sufficiently small. This is the first observation of such an induction time in micellar aggregation.     

Study of chiral property of nuclear matter through measurements of Φ meson decays

The experiment E325 being performed at KEK 12GeV-PS is to investigate the chiral property of QCD in dense matter through the measurements of vector mesons which decay inside nucleus. The status of the experiment and the preliminary mass distribution of Φ → K⁺K⁻ decays are presented.