Differential cross sections have been extracted from exclusive and kinematically complete high-statistics measurements of quasifree polarized $\vec n$p scattering performed in the energy region of ...the d* (2380) dibaryon resonance covering the range of beam energies Tn = 0.98 - 1.29 GeV (√ s = 2.32 - 2.44 GeV). The experiment was carried out with the WASA-at-COSY setup having a polarized deuteron beam impinged on the hydrogen pellet target and utilizing the quasifree process dp → np + pspectator. In this way the np differential cross section σ (Θ) was measured over a large angular range. The obtained angular distributions complement the corresponding analyzing power Ay (Θ) measurements published previously. A SAID partial-wave analysis incorporating the new data strengthens the finding of a resonance pole in the coupled 3D3 - 3G3 waves.
The differential cross section for the H-1(d, pp)n breakup reaction at deuteron beam energy of 340 MeV has been measured with the use of the WASA detector at COSY-Jillich. The set of proton-proton ...coincidences registered at the Forward Detector has been analyzed on a dense grid of kinematic variables, giving in total around 5600 data points. The cross-section data are compared to theoretical predictions based on the state-ofthe-art nucleon-nucleon potentials, combined with a three-nucleon force or the Coulomb interaction or carried out in a relativistic regime.
Two new NiO-based catalysts, NiOBDP and Ni/NiOBDP, were synthesized by a calcination of NiBDP MOF (BDP = 1,4-bis(pyrazol-4-yl)benzene) in air. Calcination performed in a N2/O2 (80:20 %) atmosphere in ...the absence of any reducing agent, led to a mixed composite Ni/NiOBDP containing some Ni(0) NPs. In contrast, thermal decomposition of Ni-MOF in an air atmosphere provided only NiOBDP. Both catalysts presented high activity in selective transfer hydrogenation of acetophenone and 4-nitrophenol in mild conditions, using 2-propanol/NaOH or NaBH4/H2O as reducing agents. Catalytic activity of Ni/NiOBDP was higher compared to NiOBDP suggesting the participation of Ni(0) in the hydrogenation process.
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The NiOBDP and Ni/NiOBDP composites obtained by calcination of NiBDP MOF (MOF = metal–organic framework; BDP = 1,4-Bis(pyrazol-4-yl)benzene) in air at 700 °C were characterized by XRD (X-ray diffraction), TEM (Transmission electron microscopy), XPS (X-ray photoelectron spectroscopy) and Raman spectroscopy. Both nanocatalysts presented high activity in selective transfer hydrogenation of acetophenone (APh) and 4-nitrophenol (4-NP) in mild conditions, using 2-propanol/NaOH or NaBH4/H2O as reducing agents. In both reactions, the catalytic activity of Ni/NiOBDP was higher compared to NiOBDP suggesting the participation of Ni(0) in the hydrogenation process.
We report on the experimental search for the bound state of an η meson and He3 nucleus performed using the WASA-at-COSY detector setup. In order to search for the η-mesic nucleus decay, the pd→3He2γ ...and pd→3He6γ channels have been analysed. These reactions manifest the direct decay of the η meson bound in a He3 nucleus. This non-mesonic decay channel has been considered for the first time. When taking into account only statistical errors, the obtained excitation functions reveal a slight indication for a possible bound state signal corresponding to a 3He-η nucleus width Γ above 20 MeV and binding energy Bs between 0 and 15 MeV. However, the determined cross sections are consistent with zero in the range of the systematic uncertainty. Therefore, as final result we estimate only the upper limit for the cross section of the η-mesic He3 nucleus formation followed by the η meson decay which varies between 2 nb and 15 nb depending on possible bound state parameters.
The WASA-at-COSY experiment has collected 3 x 10(7) events with eta mesons produced via the reaction pd -> He-3 eta at T = 1.0 GeV. Using this data set, we evaluate the branching ratios of the ...decays eta -> pi(+)pi(-)gamma, eta -> e(+)e(-)gamma, eta -> pi(+)pi(-)e(+)e(-), and eta -> e(+)e(-)e(+)e(-). The branching ratios are normalized to the eta -> pi(+)pi(-) pi(0) decay. In addition an upper limit on a CP-violating asymmetry in eta -> pi(+)pi(-)e(+)e(-) is extracted.
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