[en] In this work, starting from a realistic nucleon-nucleon interaction based on the one-boson exchange model for the nuclear force, we attempted a microscopic derivation of the effective interaction which may be appropriate for nuclear structure as well as for nucleon-nucleus scattering problems. Short-range correlations and medium polarization as well as relativistic effects on both particle-hole and Δ-hole interactions have been investigated. For the nucleon-nucleon case short-range correlations are basically restricted to S-states and affect mainly the central components of the effective interaction. In contrast, the Δ-nucleon interaction is essentially unaffected by short-range correlations due to the Pauli principle restrictions and the momentum mismatch between the central components of the correlation operator and the tensor component of the bare transition potential. Based on these analyses it is shown that short-range correlation effects can be summarized in a very simple correlation operator. (orig./HSI)

[en] We present results for the pp → ppω reaction studied by considering two different scenarios: with and without the inclusion of nucleon resonance excitations. The recently measured angular distribution by the COSY-TOF Collaboration at an excess energy of Q = 173 MeV and the energy dependence of the total cross section data for π^-p → ωn are used to calibrate the model parameters. The inclusion of nucleon resonances improves the theoretical prediction for the energy dependence of the total cross section in pp → ppω at excess energies Q < 31 MeV. However, it still underestimates the data by about a factor of two, and remains a problem in understanding the reaction mechanism

[en] A Si microstructure on a Si (1 1 1) 7x7 surface was investigated by a noncontact atomic force microscopy (ncAFM) and a scanning Kelvin probe microscopy (SKPM) in ultra high vacuum. The Si microstructure was generated by intermittent contact of a cantilever tip. It was found by the ncAFM and SKPM observations that the Si mound with a height of 1 A and a width of 30 nm was generated, and the surface potential of the small mound was 0.1 V lower than that of the 7x7 domain. A quenched Si (1 1 1) surface was also observed by the ncAFM and SKPM. The differences in height and potential between the reconstructed 7x7 and the disordered 1x1 domains were about 1 A and 0.1 V, respectively. Therefore, it was concluded that there appeared the disordered 1x1 structure on the surface of the Si small mound, lowering the surface potential by 0.1 V

[en] It is demonstrated that measurements of photon asymmetry in the γn→K^-K⁺n reaction, can most likely determine the parity of the newly discovered Θ⁺ pentaquark. We predict that if the parity of Θ⁺ is positive, the photon asymmetry is significantly positive; if the parity is negative, the photon asymmetry is significantly negative. If the background contribution is large, the photon asymmetry may become very small in magnitude, thereby making it difficult to distinguish between the positive and negative parity results. However, even in this case, a combined analysis of the (K⁺n) invariant mass distribution and photon asymmetry should allow a determination of the parity of Θ⁺

No abstract available

[en] A novel multilayer structure composed of a NBCO groundplane and stannate isolation layers was fabricated in order to improve the quality of Josephson characteristics and wiring layers on a buried groundplane. The fabricated junctions exhibited high magnetic modulation of I_c exceeding 90% and an I_cR_n product of 0.75 mV at 30 K. The sheet inductances of the counter-electrode and the base-electrode wiring were 1.1 and 1.3 pH, respectively, nearly independent of a temperature ranging from 20 to 30 K. We also fabricated an HTS-SFQ ring oscillator circuit including 21 junctions by adopting this novel multilayer and confirmed a proper operation of the ring oscillator at 20-30 K. The maximum output voltage of the ring oscillator was observed to be 0.06 mV at 30 K and 0.12 mV at 20 K, indicating the signal delay time per stage to be 3.4 and 1.8 ps, respectively

[en] Published in summary form only

[en] It is shown that core polarization effects, which are known to screen the spin-isospin independent part of the effective particle-hole interaction, also strongly influence their tensor components. The resulting tensor force is much weaker and of shorter range than that derived from a G-matrix. (orig.)

[en] A method of identification and estimation of swirling motion in complicated flow and its application are presented. Classification of flow can be performed with velocity gradient tensor and its eigenvalue, and complex eigenvalue indicates that flow is swirling motion. Here the complex number of the eigenvalue is defined as swirling function, and the local maximum point of swirling function is assumed to be the axis of swirling. This method enables to identify the swirling motion hidden in complicated flow, which is impossible to identify with velocity field or streamline. This definition prevents misunderstanding between swirling flow and non-swirling flow with (non-zero) vorticity, and the intensity of swirling can be estimated. This method has been applied to the flow inside a nuclear reactor vessel. (authors)

[en] Published in summary form only