Evidence of Υ(1S)→J/ψ+χc1\Upsilon(1S) \to J/\psi+\chi_{c1} and search for double-charmonium production in Υ(1S)\Upsilon(1S) and Υ(2S)\Upsilon(2S) decays

Using data samples of $102\times10^6$ $\Upsilon(1S)$ and $158\times10^6$ $\Upsilon(2S)$ events collected with the Belle detector, a first experimental search has been made for double-charmonium production in the exclusive decays $\Upsilon(1S,2S)\rightarrow J/\psi(\psi')+X$, where $X=\eta_c$, $\chi_{cJ} (J=~0,~1,~2)$, $\eta_c(2S)$, $X(3940)$, and $X(4160)$. No significant signal is observed in the spectra of the mass recoiling against the reconstructed $J/\psi$ or $\psi'$ except for the evidence of $\chi_{c1}$ production with a significance of $4.6\sigma$ for $\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}$. The measured branching fraction \BR(\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}) is $(3.90\pm1.21(\rm stat.)\pm0.23 (\rm syst.))\times10^{-6}$. The $90\%$ confidence level upper limits on the branching fractions of the other modes having a significance of less than $3\sigma$ are determined. These results are consistent with theoretical calculations using the nonrelativistic QCD factorization approach.Comment: 12 pages, 4 figures, 1 table. The fit range was extended to include X(4160) signal according to referee's suggestions. Other results unchanged. Paper was accepted for publication as a regular article in Physical Review

Compressibility of two Na-rich clinopyroxenes: A synchrotron single-crystal X-ray diffraction study

Synchrotron-based high-pressure single-crystal X-ray diffraction experiments were conducted on synthetic clinopyroxenes at room temperature to a maximum pressure of 40 GPa. We studied two crystals with different compositions. A Na-Ti-pyroxene with formula (Na0.86Mg0.14)(Mg0.57Ti0.43)Si2O6 synthesized at P = 7 GPa and T = 1700 °C, and a Na-pyroxene with composition (Na0.886Mg0.085Fe0.029) (Si0.442Mg0.390Fe0.168)Si2O6 synthesized at P = 15 GPa and T = 1500 °C. These phases were found to be monoclinic with the space group C2/c and exhibit KTo of 106.8(2), 121.8(4) GPa, respectively. Na-Tipyroxene is more compressible than Fe-bearing Na-Mg-Si-pyroxene, likely due to the fact that the FeO6 octahedron is significantly more rigid than MgO6 at high pressure. The formation of Na-rich pyroxenes in the deep mantle is related to crystallization of low-degree alkaline carbonate-silicate melts formed when the crust and mantle interact during the slab descent and its stagnation in the transition zone

Effect of Sc, Hf, and Yb Additions on Superplasticity of a Fine-Grained Al-0.4%Zr Alloy

This research was undertaken to study the way deformation behaves in ultrafine-grained (UFG)-conducting Al-Zr alloys doped with Sc, Hf, and Yb. All in all, eight alloys were studied with zirconium partially replaced by Sc, Hf, and/or Yb. Doping elements (X = Zr, Sc, Hf, Yb) in the alloys totaled 0.4 wt.%. The choice of doping elements was conditioned by the possible precipitation of Al3X particles with L12 structure in the course of annealing these alloys. Such particles provide higher thermal stability of a nonequilibrium UFG microstructure. Initial coarse-grained samples were obtained by induction casting. A UFG microstructure in the alloys was formed by equal-channel angular pressing (ECAP) at 225 °C. Superplasticity tests were carried out at temperatures ranging from 300 to 500 °C and strain rates varying between 3.3 × 10−4 and 3.3 × 10−1 s−1. The highest values of elongation to failure are observed in Sc-doped alloys. A UFG Al-0.2%Zr-0.1%Sc-0.1%Hf alloy has maximum ductility: at 450 °C and a strain rate of 3.3 × 10−3 s−1, relative elongation to failure reaches 765%. At the onset of superplasticity, stress (σ)–strain (ε) curves are characterized by a stage of homogeneous (uniform) strain and a long stage of localized plastic flow. The dependence of homogeneous (uniform) strain (εeq) on test temperature in UFG Sc-doped alloys is increasing uniformly, which is not the case for other UFG alloys, with εeq(T) dependence peaking at 350–400 °C. The strain rate sensitivity coefficient of flow stress m is small and does not exceed 0.26–0.3 at 400–500 °C. In UFG alloys containing no Sc, the m coefficient is observed to go down to 0.12–0.18 at 500 °C. It has been suggested that lower m values are driven by intensive grain growth and pore formation in large Al3X particles, which develop specifically at an ingot crystallization stage

Competition of multiband superconducting and magnetic order in ErNi2B2C observed by Andreev reflection

Point contacts (PC) Andreev reflection dV/dI spectra for the antiferromagnetic (TN≃6 K) superconductor (Tc≃11 K) ErNi2B2C have been measured for the two main crystallographic directions. The observed retention of the Andreev reflection minima in dV/dI up to Tc directly points to an unusual superconducting order parameter (OP) vanishing at Tc. The temperature dependence of the OP was obtained from dV/dI using the recent theory of Andreev reflection including the pair-breaking effect. For the first time the existence of two superconducting OPs in ErNi2B2C is shown. A distinct decrease of both OPs as temperature is lowered below TN is observed.This is the version of the article before peer review or editing, as submitted by an author to European Physical Society Letters (EPL).  IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it.  The Version of Record is available online at DOI: 10.1209/0295-5075/83/37003. Copyright 2008 EPLA

The Cutter-Loaders Works in Kansk-Achinsk Coal Mines for Kranlayn Use Modernization

Рассматривается возможность применения экскаваторов кранлайн на угольных разрезах Канско-Ачинского бассейна: «Березовский-1», «Бородинский», «Назаровский» и связанные с этим изменения элементов систем разработки.This article discusses the possibility of using kranlayn in Kansk-Achinsk coal mines «Berezovsky-1», «Borodino», «Nazarovo» and the related changes of design elements

The Cutter-Loaders Works in Kansk-Achinsk Coal Mines for Kranlayn Use Modernization

Рассматривается возможность применения экскаваторов кранлайн на угольных разрезах Канско-Ачинского бассейна: «Березовский-1», «Бородинский», «Назаровский» и связанные с этим изменения элементов систем разработки.This article discusses the possibility of using kranlayn in Kansk-Achinsk coal mines «Berezovsky-1», «Borodino», «Nazarovo» and the related changes of design elements