[en] We report measurements of the branching fractions for B⁰→π⁺π^- , K⁺π^- , K⁺K^- , and K⁰π⁰ and B⁺→π⁺π⁰ , K⁺π⁰ , K⁰π⁺ , and K⁺ bar K⁰ , based on 10.4 fb^-1 of data collected on the Υ(4S) resonance with the Belle detector. We find B(B⁰→π⁺π^-)=(0.56^+0.23+0.04_{-0.20-0.0 5}) x 10^-5 , B(B⁰→K⁺π^-)=(1.93^{+0.34 +0.15}_-0.32-0.06) x 10^-5 , B(B⁺→K⁺π⁰)=(1.63^+0.35+0.16_{-0.33-0.1 8}) x 10^-5 , B(B⁺→K⁰π⁺)=(1.37^+0.57+0.19_{-0.48-0.1 8}) x 10^-5 , and B(B⁰→K⁰π⁰)=(1.60^+0.72+0.25_{-0.59-0.2 7}) x 10^-5 . We also set upper limits on the branching fractions for B⁺→π⁺π⁰ , B⁰→K⁺K^- , and B⁺→K⁺bar K⁰

[en] We present a measurement of the standard model CP violation parameter sin< hspace SPACE=''-0.167''>2φ₁ based on a 29.1 fb^-1 data sample collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e⁺e^- collider. One neutral B meson is fully reconstructed as a J/ψK_S , ψ(2S)K_S , χ_c1K_S , η_cK_S , J/ψK_L , or J/ψK^*0 decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin< hspace SPACE=''-0.167''>2φ₁=0.99± 0.14(stat)±0.06(syst) . We conclude that we have observed CP violation in the neutral B meson system

[en] We report observations of the Cabibbo suppressed decays B→D^(*)K^- using a 10.4 fb^-1 data sample accumulated at the Υ(4S) resonance with the Belle detector at the KEKB e⁺e^- storage ring. We find that the ratios of Cabibbo suppressed to Cabibbo favored branching fractions are B(B^-→D⁰K^-)/B(B^- →D⁰π^-)= 0.079± 0.009± 0.006 , B( bar B⁰ →D⁺K^-)/B( bar B⁰→ D⁺π^-) =0.068 ±0.015 ±0.007 , B(B^-→ D^*0K^-) /B(B^- →D^*0π^-)= 0.078± 0.019± 0.009 , and B(bar B⁰→ D^*+K^-)/ B(bar B⁰→ D^*+π^-)=0.074±0.015± 0.006 . These are the first observations of the B→D⁺K^- , D^*0K^- , and D^*+K^- decay processes

[en] Pressure calibration experiments were performed at room temperature for a Drickamer-type apparatus using a composite anvil system with a sintered diamond anvil, which can be replaced by nano-polycrystalline diamond anvil. The culet diameter and tapering angle are 1.0 mm and 30⁰, respectively. Transitions in Fe₂O₃ (50 GPa) and CoO (55 GPa) were observed at 39.6 and 38.5 kN, respectively, by electrical resistance measurements. Pressure of about 120 GPa can be generated at the maximum load of 98 kN by assuming the linear extrapolation of the obtained load-pressure relation. The Drickamer-type apparatus with nano-polycrystalline diamond anvils has potential to generate pressure covering the whole lower mantle.

[en] We describe here a new concept of a Cherenkov detector for particle identification by means of measuring the Time-of-Propagation (TOP) of Cherenkov photons

[en] The Time-Of-Propagation (TOP) counter measures both the time and position information of radiated photons with high resolutions to distinguish the Cherenkov angles between different particle species. Current R and D status is reported. We also propose a further simplified version of the TOP-counter

[en] The lining structure of LMFBR (Liquid Metal cooled Fast Breeder Reactor) has an important role to prohibit leaking sodium from touching a concrete floor in a sodium leakage incident. JNC (Japan Nuclear Cycle Development Institute) experienced a sodium leakage incident in 1995 in the secondary heat transport system room of the prototype LMFBR MONJU. In this incident, a part of the liner was covered with a certain amount of high temperature leaked sodium and its compounds. Visible but small distortion and thinning of the liner were detected, which were due to heating by sodium fire and chemical corrosion, respectively. To simulate the MONJU incident, JNC conducted a series of sodium leakage tests, in one of which severer corrosion (molten salt type corrosion) than that in the MONJU incident was observed. In order to secure the conservativeness in the integrity assessment of the liner, consideration of a severest corrosion process was demanded. This means that the loss of parts of the structure with time should be considered in the structural analyses. In this study a modeling of thinning process of the liner was developed in order to realize reasonable analysis from the point of view of actual phenomena. The concept of the method is to release the stress of the lost region by using artificial creep and reducing Young's modulus. The necessity of this kind of model and the validity was verified through an application analysis of the liner in the secondary heat transport system room of MONJU. (authors)

[en] We have studied the timing property of a Hybrid Avalanche PhotoDiode, Hamamatsu R7110U-07, and attained a time resolution of σ_t∼150 ps for single photons and ≤100 ps for a few photons under certain conditions of photocathode voltage and diode reverse bias voltage. Relation between the achievable timing resolution and a multiplication gain is discussed, especially in realizing σ_t≤100 ps for single photons

[en] We report the specific heat measurement of single crystalline Ce₃Pd₂₀Si₆ and the resultant magnetic phase diagram for the direction of B // [100]. In zero field, we confirmed two successive phase transitions at T = 0.24 K and 0.4 K. The magnetic phase diagram clearly shows a phase boundary of paramagnetic phase I, quadrupole ordered phase II and II'.

[en] By shortening the distance between the photocathode and the first dynode to 1 mm and using a finer mesh size of 2500 lines/in. with 4 μm^φ, a 24 anode linear-array of fine-mesh photomultiplier tube has produced a clear single-photon peak in its pulse-height distribution under a strong magnetic field of B≤1 T, and provided σ_TTS=100 ps of transit time spread (TTS) and 85% of photoelectron detection efficiency