Measurement of γp→K + Λ and γp→K + Σ 0 at photon energies up to 1.47 GeV

The reactions pK ⁺ and pK ^{+ 0} have been measured with the multiparticle detector system SAPHIR at ELSA in Bonn. Besides the differential cross sections the polarization and, for the first time, the ⁰ polarization have been determined in a photon induced reaction. All data are presented as functions of the photon energy (from threshold up to 1.47 GeV) and of the kaon production angle (0°–180°). The polarization of both and ⁰ is substantial at all energies and varies strongly with the production angle.This work is supported by the Bundesminister für Forschung und Technologie (BMFT), FK 06 BN 621 I     

Structural aspects and electronic absorption of the hydroxyphenanthroperylene quinones fringelit D,hypericin, and stentorin

Summary PPP type semiempirical quantum chemical calculations of absorption spectra were performed for hypericin, fringelit D, stentorin, and their respective conformers, tautomers, and deprotonated species. The results agree with the experimental absorption spectra of hypericin, stentorin, and fringelit D, their deprotonated species, and the polarized absorption spectra of an ,-long chain appended hypericin derivative embedded in stretched polyethylene.

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Strukturelle Aspekte und elektronische Absorptionseigenschaften der Hydroxyphenanthroperylenchinone Fringelit D, Hypericin und Stentorin

Zusammenfassung Semiempirische quantenchemische Rechnungen (PPP-Typ) der Absorptions-spektren von Hypericin, Fringelit D, Stentorin und ihrer Konformeren, Tautomeren und deren Deprotonierungsprodukten wurden durchgeführt. Die Resultate stehen in Einklang mit den experimentellen Absorptionsspektren von Hypericin, Fringelit D, Stentorin, ihrer Deprotonierungsprodukte und dem polarisierten Absorptionsspektrum eines in gestrecktem Polyethylen eingebetteten ,-substituierten Hypericinderivates.