Search

We study bottomonium production in association with an $$\eta $$ meson in $$e^+e^-$$ annihilations near the $$\varUpsilon (5S)$$ , at a centre-of-mass energy of $$\sqrt{s}=10.866$$ GeV. The results are based on the 121.4 fb $$^{-1}$$ data sample collected by the Belle experiment at the asymmetric-energy KEKB collider. Only the $$\eta $$ meson is reconstructed and the missing-mass spectrum of $$\eta $$ candidates is investigated. We observe the $$e^+e^-\rightarrow \eta \varUpsilon _J(1D)$$ process and find evidence for the $$e^+e^-\rightarrow \eta \varUpsilon (2S)$$ process, while no significant signals of $$\varUpsilon (1S)$$ , $$h_b(1P)$$ , nor $$h_b(2P)$$ are found. Cross sections for the studied processes are reported.

We report the first observation of the $$\Xi _{c}(2930)^0$$ charmed-strange baryon with a significance greater than 5 $$\sigma $$ . The $$\Xi _{c}(2930)^0$$ is found in its decay to $$K^- \Lambda _{c}^+$$ in $$B^{-} \rightarrow K^{-} \Lambda _{c}^{+} \bar{\Lambda }_{c}^{-}$$ decays. The measured mass and width are $$[2928.9 \pm 3.0(\mathrm stat.)^{+0.9}_{-12.0}(\mathrm syst.)]$$ MeV/ $$c^{2}$$ and $$[19.5 \pm 8.4(\mathrm stat.) ^{+5.9}_{-7.9}(\mathrm syst.)]$$ MeV, respectively, and the product branching fraction is $$\mathcal{B}(B^{-} \rightarrow \Xi _{c}(2930)^0 \bar{\Lambda }_{c}^{-}) \mathcal{B}(\Xi _{c}(2930)^0 \rightarrow K^- \Lambda _{c}^{+})=[1.73 \pm 0.45(\mathrm stat.) \pm 0.21(\mathrm syst.)]\times 10^{-4}$$ . We also measure $$\mathcal{B}(B^{-} \rightarrow K^{-} \Lambda _{c}^{+} \bar{\Lambda }_{c}^{-}) = [4.80 \pm 0.43(\mathrm stat.) \pm 0.60(\mathrm syst.)] \times 10^{-4}$$ with improved precision, and search for the charmonium-like state Y(4660) and its spin partner, $$Y_{\eta }$$ , in the $$\Lambda _{c}^{+}\bar{\Lambda }_{c}^{-}$$ invariant mass spectrum. No clear signals of the Y(4660) nor its spin partner are observed and the 90% credibility level (C.L.) upper limits on their production rates are determined. These measurements are obtained from a sample of $$(772\pm 11)\times 10^{6} B\bar{B}$$ pairs collected at the $$\Upsilon (4S)$$ resonance by the Belle detector at the KEKB asymmetric energy electron–positron collider.

This study aimed to present a reinforced concrete block system that reduces the flange thickness of the existing form block used in new buildings and optimizes the web form, and can thus capable of being used in the seismic retrofit of new and existing buildings. By conducting a compression test and finite element analysis based on the block and grouted concrete strength, it attempted to determine the compression capacity of the form block that can be used in new construction and seismic retrofit. As a result, the comparison of the strength equation from Architectural Institute of Japan to the prism compression test showed that the mortar coefficient of 0.55 was suitable instead of 0.75 recommended in the equation. The stress–strain relation of the block was proposed as a bi-linear model based on the compression test result of the single form block. Using the proposed model, finite element analysis was conducted on the prism specimens, and it was shown that the proposed model predicted the compression behavior of the form block appropriately.

The total number of {110} grains after final annealing increased with preannealing and was greater in a hydrogen atmosphere than under a high vacuum. Magnetic induction decreased with increasing total number of the {110} grains. This is attributed to the increase in {110} grain size, the decrease in a range for the selective growth of {100} or {111} grains, and thus the increase in number of {110} grains that show a deviation angle between the \( \langle 001\rangle \) crystal and the rolling directions.

Coarse powders of 200∼300 μm size and fine powders below 45 μm size were blended with various ratios, and then synthesized by spark plasma sintering method. The use of coarse powders was beneficial to improve the crystallographic orientation and addition of fine powders reduced the voids existing between coarse powders. When 20 wt% of fine powders were blended with coarse powders, the sintered compound exhibited the maximum figure-of-merit.

We search for CP violation in the decay ${D^{+}}\to K_S^0{K^{+}}$ using a data sample with an integrated luminosity of 977 fb−1 collected with the Belle detector at the KEKB e + e − asymmetric-energy collider. No CP violation has been observed and the CP asymmetry in ${D^{+}}\to K_S^0{K^{+}}$ decay is measured to be (−0.25 ± 0.28 ± 0.14)%, which is the most sensitive measurement to date. After subtracting CP violation due to ${K^0}-{{\overline{K}}^0}$ mixing, the CP asymmetry in ${D^{+}}\to {{\overline{K}}^0}{K^{+}}$ decay is found to be (+0.08 ± 0.28 ± 0.14)%.

THE Coma cluster is a rich cluster of galaxies nested in an even larger supercluster of galaxies. The plane of the supercluster seems to be defined by the Coma cluster itself and another galaxy cluster, Abell 1367, which lies ∼40 Mpc farther west1, 2. The largest structures known are the giant voids and superclusters which are as large as 70h−175 Mpc (refs 3–5). The Coma cluster of galaxies seems to be located on the rim of a giant void6 in the three-dimensional distribution of galaxies. Here we describe the detection of faint, supercluster-scale radio emission at 326 MHz that extends between the Coma cluster of galaxies (Abell 1656) and the Abell 1367 cluster and which is apparently not associated with any individual galaxy system in the complex. The radiation's synchrotron origin implies the existence of a large-scale intercluster magnetic field with an estimated strength of 0.3–0.6 μG, which is remarkably strong. The synchrotron-emitting relativistic electrons cannot be older than a few times 108 yr, but we speculate that the magnetic field is the fossil of a pre-galactic primaeval field, which was amplified in the course of the formation of intergalactic voids and superclusters.

Response equations are obtained for hollow spheres of elastic, perfectly plastic material under hydrostatic loading, unloading, reverse loading, and reloading. Some interesting features of unloading, reverse loading, and reloading responses are observed. For sufficiently thick-walled spheres, reverse yielding occurs during unloading. The critical initial porosity is obtained for reverse yielding during unloading. Precompaction lowers the magnitude of the pressure maximum and delays the occurrence of the instability point.