A study of the centrally produced π+π−π0 system formed in the reactionpp→p f (π+π−π0)p s at 300 GeV/c

The reactionpp→p _f (π⁺π^?π⁰)p _s , where the π⁺π^?π⁰ system is centrally produced, has been studied at 300 GeV/c. The π⁺π^?π⁰ mass spectrum shows evidence for the η, ω anda ₂ (1320) as well as an enhancement in thea ₁ (1260) region. A Dalitz plot analysis of the π⁺π^?π⁰ system has been performed. Thea ₁ (1260) parameters coming from the fit of the 1⁺ S wave arem=1208±15 MeV and Γ=430±50 MeV. No evidence is found for theh ₁(1170) orh ₁(1380).     

The production ofJ/ψ in 200 GeV/A oxygen-uranium interactions

The dimuon production in 200 GeV/nucleon oxygen-uranium interactions is studied by the NA 38 Collaboration. The production ofJ/ψ, correlated with the transverse energyET, is investigated and compared to the continuum, as a function of the dimuon massM and transverse momentumPT. A value of 0.64±0.06 is found for the ratio (ψ/Continuum at highET)/(ψ/Continuum at lowET), from which theJ/ψ relative suppression can be extracted. This suppression is enhanced at lowPT.     

Production ofρ +, −, 0 (770),η(550), ω(783) andf 2(1270) mesons in\bar v neon and ν neon charged current interactions

The production of the meson resonances ?(770) (all three charge states), η(550), ω(783) andf ₂(1270) in \(\bar v\) Ne and ν Ne charged current interactions is investigated in a bubble chamber experiment with BEBC at CERN. Except for thef ₂, the main features of resonance production are reasonably well described by the Lund model, although the average resonance multiplicities are overestimated by the model by (67±30)%. The average multiplicities of all resonances, including thef ₂, are well reproduced by a semiempirical model, whose parameters were determined from hadron interaction data.     

Long-lived near-infrared luminescent lanthanide complexes of imidodiphosphinate "shell" ligands

Near-infrared emitting complexes of Nd(III), Er(III), and Yb(III) based on hexacoordinate lanthanide ions with an aryl functionalized imidodiphosphinate ligand, tpip, have been synthesized and fully characterized. Three tpip ligands form a shell around the lanthanide with the ligand coordinating via the two oxygens leading to neutral complexes, Ln(tpip)3. In the X-ray crystal structures of Er(III) and Nd(III) complexes there is evidence of CH-pi interactions between the phenyl groups. Photophysical investigations of solution samples of the complexes demonstrate that all complexes exhibit relatively long luminescence lifetimes in nondeuteurated solvents. Luminescence studies of powder samples have also been recorded for examination of the properties of NIR complexes in the solid state for potential material applications. The results underline the effective shielding of the lanthanide by the twelve phenyl groups of the tpip ligands and the reduction of high-energy vibrations in close proximity to the lanthanide, both features important in the design of NIR emitting lanthanide complexes.     

Thermal analysis of nickel(II) complexes with some N-monosubstituted ethylenediamines

The thermal analysis of complexes of N-R-ethylenediamine, where R=ethyl, propyl, 2-hydroxyethyl, 2-hydroxypropyl and 3-hydroxypropyl, with the halides, thiocyanate and sulphate of nickel is reported. The procedural decomposition temperatures of the complexes are given and considered in relation to the structures of the compounds.

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Zusammenfassung Es wurde über die thermoanalytische Prüfung der Komplexe von N-R-Äthylendiamin (R=Äthyl, Propyl, 2-HydroxyÄthyl, 2-Hydroxypropyl und 3-Hydroxypropyl) mit Nickelhalogenid, -sulfat und -rhodanid unter Angabe der entsprechenden Zersetzungstemperaturen in Zusammenhang mit den strukturalen Umwandlungen der Verbindungen berichtet.

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Résumé On communique les résultats relatifs à l'analyse thermique des complexes formés par la N-R-éthylènediamine (R=éthyl, propyl, hydroxy-2 éthyl, hydroxy-2 propyl et hydroxy-3 propyl) avec les halogénures, le thiocyanate et le sulfate de nickel. On a cherché à établir une relation entre la température observée pour la décomposition et la structure des composés.

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N-R-, R= , , 2-, 2- 3-, , . .

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We wish to thank the Science Research Council for a grant to B. L. O'Leary.     

Quantitative Spektralanalyse

Ohne Zusammenfassung