2,216 research outputs found

    Studies of ecomorphological variations of the European hare (Lepus europaeus) in Turkey

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    Hares (Lepus spp.) are widely distributed across the globe and are adapted to diverse climatic conditions. In order to study the ecomorphological variations of hares from Turkey, the body and cranial measurements and body weight, as well as coat color types, of 138 hares collected from all over Turkey between 2006 and 2012, were examined. Statistically significant differences between regional samples (p <0.05, ANOVA) only in terms of body weight and hindfoot length were found; however, there were a good number of external phenotypes, particularly in terms of coat color variants of the hare specimens. Furthermore, populations had similar variations in terms of morphometric measurement, body weight and coat coloration between different geographical regions. Turkish hares did not exhibit clinal variations from south to north in body and cranial measurements depending on the mean annual temperatures and precipitation. Therefore, it was assumed that all of these variations might be a polymorphism related to the local adaptations and high level of admixture of gene pools in Anatolia

    Assembly of Molten Transition Metal Salt-Surfactant in a Confined Space for the Synthesis of Mesoporous Metal Oxide-Rich Metal Oxide-Silica Thin Films

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    Cataloged from PDF version of article.ABSTRACT: Uniform and homogeneous coating of mesoporous materials with an active (catalytically, photonic, electrical) nanostructure can be very useful for a number of applications. Understanding chemical reactions in a confined space is important in order to design new advanced materials. In this work, we demonstrate that an extensive amount (as high as 53 mol percent) of transition metal salts can be confined between silica walls and two surfactant domains (cetyltrimethylammonium bromide, CTAB, and lauryl ether, C12H25(OCH2CH2)10OH, C12EO10) as molten salts and then converted into sponge-like mesoporous silica metal oxides by thermal annealing. This investigation has been carried out using two different salts, namely, zinc nitrate hexahydrate, [Zn(H2O)6](NO3)2, and cadmium nitrate tetrahydrate, [Cd(H2O)4](NO3)2, in a broad range of salt concentrations. The ZnO (or CdO) layers are as thin as about ∼1.6 nm and are homogenously coated as crystalline nano-islands over the silica pore walls

    Study of J/ψJ/\psi and ψ(3686)Σ(1385)0Σˉ(1385)0\psi(3686)\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0}

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    We study the decays of J/ψJ/\psi and ψ(3686)\psi(3686) to the final states Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0} based on a single baryon tag method using data samples of (1310.6±7.0)×106(1310.6 \pm 7.0) \times 10^{6} J/ψJ/\psi and (447.9±2.9)×106(447.9 \pm 2.9) \times 10^{6} ψ(3686)\psi(3686) events collected with the BESIII detector at the BEPCII collider. The decays to Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} are observed for the first time. The measured branching fractions of J/ψJ/\psi and ψ(3686)Ξ0Ξˉ0\psi(3686)\rightarrow\Xi^0\bar\Xi^{0} are in good agreement with, and much more precise, than the previously published results. The angular parameters for these decays are also measured for the first time. The measured angular decay parameter for J/ψΣ(1385)0Σˉ(1385)0J/\psi\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0}, α=0.64±0.03±0.10\alpha =-0.64 \pm 0.03 \pm 0.10, is found to be negative, different to the other decay processes in this measurement. In addition, the "12\% rule" and isospin symmetry in the J/ψJ/\psi and ψ(3686)ΞΞˉ\psi(3686)\rightarrow\Xi\bar\Xi and Σ(1385)Σˉ(1385)\Sigma(1385)\bar{\Sigma}(1385) systems are tested.Comment: 11 pages, 7 figures. This version is consistent with paper published in Phys.Lett. B770 (2017) 217-22

    Measurement of azimuthal asymmetries in inclusive charged dipion production in e+ee^+e^- annihilations at s\sqrt{s} = 3.65 GeV

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    We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process e+eππXe^+e^-\rightarrow \pi\pi X based on a data set of 62 pb1\rm{pb}^{-1} at the center-of-mass energy s=3.65\sqrt{s}=3.65 GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.Comment: 7 pages, 5 figure

    Observation of an anomalous line shape of the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} mass spectrum near the ppˉp\bar{p} mass threshold in J/ψγηπ+πJ/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-}

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    Using 1.09×1091.09\times10^{9} J/ψJ/\psi events collected by the BESIII experiment in 2012, we study the J/ψγηπ+πJ/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-} process and observe a significant abrupt change in the slope of the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} invariant mass distribution at the proton-antiproton (ppˉp\bar{p}) mass threshold. We use two models to characterize the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} line shape around 1.85 GeV/c21.85~\text{GeV}/c^{2}: one which explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatt\'{e} formula), and another which is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85 GeV/c21.85~\text{GeV}/c^{2} with strong couplings to ppˉp\bar{p} final states or a narrow state just below the ppˉp\bar{p} mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a ppˉp\bar{p} molecule-like state or bound state with greater than 7σ7\sigma significance

    Measurement of the e+eπ+π\mathrm e^+\mathrm e^-\rightarrow\mathrm\pi^+\mathrm\pi^- Cross Section between 600 and 900 MeV Using Initial State Radiation

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    We extract the e+eπ+πe^+e^-\rightarrow \pi^+\pi^- cross section in the energy range between 600 and 900 MeV, exploiting the method of initial state radiation. A data set with an integrated luminosity of 2.93 fb1^{-1} taken at a center-of-mass energy of 3.773 GeV with the BESIII detector at the BEPCII collider is used. The cross section is measured with a systematic uncertainty of 0.9%. We extract the pion form factor Fπ2|F_\pi|^2 as well as the contribution of the measured cross section to the leading order hadronic vacuum polarization contribution to (g2)μ(g-2)_\mu. We find this value to be aμππ,LO(600900  MeV)=(368.2±2.5stat±3.3sys)1010a_\mu^{\pi\pi,\rm LO}(600-900\;\rm MeV) = (368.2 \pm 2.5_{\rm stat} \pm 3.3_{\rm sys})\cdot 10^{-10}.Comment: 14 pages, 7 figures, accepted by PL

    Improved measurement of the absolute branching fraction of D+Kˉ0μ+νμD^{+}\rightarrow \bar K^0 \mu^{+}\nu_{\mu}

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    By analyzing 2.93 fb1^{-1} of data collected at s=3.773\sqrt s=3.773 GeV with the BESIII detector, we measure the absolute branching fraction B(D+Kˉ0μ+νμ)=(8.72±0.07stat.±0.18sys.)%{\mathcal B}(D^{+}\rightarrow\bar K^0\mu^{+}\nu_{\mu})=(8.72 \pm 0.07_{\rm stat.} \pm 0.18_{\rm sys.})\%, which is consistent with previous measurements within uncertainties but with significantly improved precision. Combining the Particle Data Group values of B(D0Kμ+νμ){\mathcal B}(D^0\to K^-\mu^+\nu_\mu), B(D+Kˉ0e+νe){\mathcal B}(D^{+}\rightarrow\bar K^0 e^{+}\nu_{e}), and the lifetimes of the D0D^0 and D+D^+ mesons with the value of B(D+Kˉ0μ+νμ){\mathcal B}(D^{+}\rightarrow\bar K^0 \mu^{+}\nu_{\mu}) measured in this work, we determine the following ratios of partial widths: Γ(D0Kμ+νμ)/Γ(D+Kˉ0μ+νμ)=0.963±0.044\Gamma(D^0\to K^-\mu^+\nu_\mu)/\Gamma(D^{+}\rightarrow\bar K^0\mu^{+}\nu_{\mu})=0.963\pm0.044 and Γ(D+Kˉ0μ+νμ)/Γ(D+Kˉ0e+νe)=0.988±0.033\Gamma(D^{+}\rightarrow\bar K^0 \mu^{+}\nu_{\mu})/\Gamma(D^{+}\rightarrow\bar K^0 e^{+}\nu_{e})=0.988\pm0.033.Comment: 9 pages; 8 figure
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