56216088
The MUSES project at the RIKEN RI beam factory
At RIKEN, the construction of Radio Isotope Beam factory, RIBF has been strated from the fiscal year 1998. In this project, the superconducting ring cyclotron with K number of 2500 will be constructed within 4 years, and the MUSES, Multi-USe Experimental Storage rings, is scheduled to start the construction just after the completion of cyclotron system. In the present paper, the outline of MUSES project is presented, while the details are given elsewhere[1, 2] and in this conference.
124527547
Measurement of the spin and magnetic moment of ²³Al
Author(s) Ozawa, A.; Matsuta, K.; Nagatomo, T.; Mihara, M.; Yamada, K.; Yamaguchi, T.; Momota, S.; Izumikawa, T.; Sumikama, T.; Nakashima, Y.; Fujiwara, H.; Kumashiro, S.; Matsumiya, R.; Ota, M.; Shinojima, D.; Tanaka, H.; Yasuno, T.; Nakajima, S.; Suzuki, T.; Yoshida, K.; Muranaka, K.; Maemura, T.; Chiba, A.; Utsuno, Y.; Fukuda, M.; Tanaka, K.; Tanihata, I.; Nojiri, Y.; Minamisono, T.; Alonso, J.R.; Krebs, G.F.; Symons, T.J.M.
120128880
Negative pion production in subthreshold heavy ion collisions
Abstract Inclusive π− spectra have been measured for 14N+C collisions at 41A, 67A, 80A and 135A MeV, the lowest energies measured for the charged pion. The cross sections fall exponentially with Tπ and the exponential slope factors at 90° in the nucleon-nucleon center of mass frame are determined. Energy distributions below a beam energy of 100A MeV are less steep than expected from the monotonic decrease of the slope factor down to 100A MeV. The production mechanism of energetic pions far below threshold is discussed for several models.
120765038
Attempts in detection of neutrons on So-called cold nuclear fusion
Neutron emissions from electrolysis of D 2 O with palladium and palladium-titanium electrodes as well as from pressurized D 2 gas with titanium alloys have been measured. The neutron detector system was so designed to have very low background condition. Neutron-γ separation technique using liquid scintillator was applied to obtain essentially no γ ray background condition for neutron counting. Special care was taken to stabilize the detection system using event-by-event data recording. No significant signal of neutron emission was observed. Upper limits of emission probability of neutron have been determined to be 6×10 -3 s -1 , 1×10 -2 s -1 , and 2.3×10 -2 s -1 for Pd electrode, Pd-Ti electrode, and pressurized gas systems. These values are orders of magnitude lower than that presented by Jones paper (0.4 s -1 ).
54645664
Study of halo structure of C from reaction cross section measurement
Abstract The reaction cross sections for 12,16 C have been measured at the energy of 83 A MeV by a new experimental method. The larger enhancement of the 16 C reaction cross section at the low energy has been used to study the density distribution of  16 C. The finite-range Glauber-model calculations for different density distributions have been compared with the experimental data. The analysis suggests that 16 C mainly has a 14 C(core) + 2n structure and shows a strong contribution of (2s1/2)2 for valence neutrons. A large extension of the neutron density distribution to a distance far from the center of the nucleus suggests the formation of neutron halo in the 16 C nucleus.
121300048
DECAY PATTERN OF PYGMY STATES OBSERVED IN NEUTRON-RICH 26Ne
Coulomb excitation of the exotic neutron-rich nucleus 26Ne on a 208Pb target was measured at 58 A.MeV in order to search for low-lying E1 strength above the neutron emission threshold. The radioactive beam was produced by fragmentation of a 95 A.MeVAr beam delivered by the RIKEN Accelerator Research Facility. The set-up included a NaI(Tl) gamma-ray array, a charged fragment hodoscope and a neutron wall. Using the invariant mass method in the 25Ne+n channel, we observe by multipole decomposition a sizable amount of E1 strength between 6 and 10 MeV excitation energy. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured.
120866230
Z-trigger system with the BELLE Central Drift Chamber
Abstract We describe the design and performance of a fast Z -trigger system with the BELLE Central Drift Chamber. It utilizes z -position information from the axial/stereo wire hits as well as the cathode strip. This system is essential to reduce the false trigger rate from caused by the spent electrons or positrons interacting with the material around the beam pipe. We tested the performance of the system using cosmic rays in a magnetic field of 1.5 T, provided by a superconducting solenoid. The trigger efficiency was 98% for a single track passing through the interaction region. This trigger was effective in rejecting tracks originating from points more than 10 cm away from the interaction point.
16998381
Graviton and Spherical Graviton Potentials in Plane-Wave Matrix Model - overview and perspective -
We briefly review our works for graviton and spherical graviton potentials in a plane-wave matrix model. To compute them, it is necessary to devise a configuration of the graviton solutions, since the plane-wave matrix model includes mass terms and hence the gravitons are not free particles as in the BFSS matrix model but harmonic oscillators or rotating particles. The configuration we proposed consists of a rotating graviton and an elliptically rotating graviton. It is applied to the two-body interaction of spherical gravitons in the SO(6) symmetric space, and then to that of point-like gravitons in the SO(3) symmetric space. In both cases the leading term of the resulting potential is 1/r^7. This result strongly suggests that the potentials should be closely related to the light-front eleven-dimensional supergravity linearized around the pp-wave background.
118850311
Phase Structure of Thermal QCD/QED:A Gauge Invariant Solution of the HTL Resummed Improved Ladder Dyson-Schwinger Equation
Based on the hard-thermal-loop resummed improved ladder Dyson-Schwinger quation for the fermion mass function, we propose a procedure how we can get the gauge invariant solution in the sense it satisfies the Ward-Takahashi identity. Results of the numerical analysis are shown and properties of the ``gauge-invariant'' solutions are discussed.
118572527
Dynamical Lifshitz-type solutions and aging phenomena
We consider time-dependent Lifshitz-type solutions in type IIB supergravity. The solutions describe a time evolution from Lifshitz spacetimes to AdS spaces. We argue the holographic relation of them to aging phenomena in condensed matter physics. The solutions have no time-translation invariance and possess the dynamical scaling symmetry with z_c=2. In addition, the time evolution corresponds to slow (nonexponential) dynamics from nonequilibrium states to the equilibrium. We also discuss a mechanism of quantum quench to generate nonequilibrium states.
120173213
Cathode image readout in the BELLE central drift chamber
Abstract We report on the design and construction of the cathode image readout section of the BELLE detector's central drift chamber. The cathode information is used for measurements of charged particle trajectory coordinates along the beam axis and the charged-track trigger. The performance is evaluated with cosmic rays using the BELLE standard readout electronics and software. The detection efficiency in nominal conditions is found to exceed 98% and the position resolution for normal incidence is about 350 μm, which satisfies the design goals of the BELLE detector.