Observation of D+ → K(+)η(') and search for CP violation in D+ → π(+)η(') decays

We report the first observation of the doubly Cabibbo-suppressed decays D(+)→K(+)η((')) using a 791 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The ratio of the branching fractions of doubly Cabibbo-suppressed relative to singly Cabibbo-suppressed D(+)→π(+)η((')) decays are B(D(+)→K(+)η)/B(D(+)→π(+)η)=(3.06±0.43±0.14)% and B(D(+)→K(+)η')/B(D(+)→π(+)η')=(3.77±0.39±0.10)%. From these, we find that the relative final-state phase difference between the tree and annihilation amplitudes in D(+) decays, δ(TA), is (72±9)° or (288±9)°. We also report the most precise measurements of CP asymmetries to date: A(CP)(D(+)→π(+)η)=(+1.74±1.13±0.19)% and A(CP)(D(+)→π(+)η')=(-0.12±1.12±0.17)%.     

Die Berechnung der Schubspannungen in der Bogenscheibe

Ohne Zusammenfassung     

Über die Intensitätsverteilung der Compton-Streuung von γ-Strahlen

Zeitschrift für Physik A Hadrons and nuclei - Es wurde eine neue Methode zur Untersuchung der Streuung von γ-Strahlen entwickelt. Mit dieser Anordnung wurde die Intensitätsverteilung...     

Effect of copper ions on the radiostability of protein-polyelectrolyte mixtures

Aqueous solution of polyacrylic acid (PAA), poly-N-isopropylacrylamide (PNIPAAm), bovine serum albumin (BSA), superoxide dismutase (SOD) and their mixtures (PAA-BSA, PAA-Cu-BSA, PNIPAAm-BSA, PAA-SOD) were irradiated in the presence of oxygen in neutral media (pH 7.0) with ⁶⁰Co γ-rays. In addition, aliquots of aqueous solutions of PAA, PAA-Cu²⁺, BSA and PAA-Cu²⁺-BSA saturated with N₂ and N₂O were also irradiated. The decomposition rate of irradiated solutions were measured by UV-visible spectrophotometry, fluorescence spectroscopy, and high performance liquid chromatography (HPLC). Protective effect of copper ions on radiolysis of aqueous solution of PAA-Cu-BSA and conversion of Cu(II) to Cu(I) was observed. The possible mechanism of this phenomenon is discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Sputtering yields for light ions as a function of angle of incidence

The sputtering yield of Ni, Mo, and Au have been measured at oblique angles of incidence for H⁺-, D⁺-, and⁴He⁺-ion irradiation in the energy region from 1 to 8 keV. The yields were determined from the weight loss of the targets. For Ni and Mo the dependence of the sputtering yield on the angle of incidence was found to be much stronger for H⁺- and D⁺-ion than for⁴He⁺-ion irradiation. In all cases the maximum in the yield was found at angles of incidence ϑ≧80°, where ϑ is the angle measured from the surface normal. Furthermore the ratio of the maximum yield to the yeild at normal incidence increases with increasing surface binding energy of the target material as well as with increasing ion energy in the energy region inveestigated. The results are discussed qualitatively in view of a model for the sputtering mechanism for light ions.     

The synthesis and electrochemical behaviour of carbazole-substituted phthalocyanines

The syntheses of new cobalt and zinc phthalocyanine complexes containing carbazole (Cz) substituents at the peripheral positions are reported (CzCoPc and CzZnPc). The reaction of Cz with 4-iodophthalonitrile in the presence of a catalytic amount of copper(I) oxide and potassium carbonate led to the formation of 4-(9H-carbazol-9-yl) phthalonitrile. Furthermore, by heating the dinitrile and anhydrous metal salts (CoCl₂, Zn(CH₃COO)₂) at 160 °C in n-hexanol in the presence of DBU, the phthalocyanines were obtained. They were characterised by ¹H NMR, FT-IR, UV-Vis and MS spectroscopic data. Aggregation behaviours of Pcs were investigated in THF. Electrochemical redox behaviour of CzCoPc was investigated by cyclic voltammetry depending on the potential range, and the oxidation and reduction products were followed by UV-Visible absorption measurements. Polymerisation of CzCoPc was carried out by potentiodynamic methods on glassy carbon electrode, and the catalytic activity of resulting polymer (P[CzCoPc]) was tested comparatively with polycarbazole (PCz)-coated electrode for dopamine and better response was obtained for P[CzCoPc] modified electrode.     

The question of the reversibility in the aminomercuration of olefins. Synthesis of N-aryl-9-azabicyclo[4.2.1]and [3.3.1] nonanes by aminomercuration of cis-cis- 1.5-cyclooctadiene

The aminomercuration of olefins is found to be a reversible or irreversible process depending on the nature of the mercury(II) salt employed. This is in clear contrast with the mechanism of oxymercuration reactions. A selective synthesis of the title compounds is described by kinetically or thermodinamically controlled aminomercuration of cis-cis-1,5-cycloctadiene.     

SIMS-Analyse von Wasserstoff in Si-Proben

Zusammenfassung Um die optimalen Bedingungen für den Wasserstoffnachweis in Festkörpern zu finden, wurden systematische Untersuchungen an mit Wasserstoff bzw. Deuterium implantierten Si-Proben durchgeführt. Es wurden die SIMS-Tiefenprofile analysiert, die Sputterraten gemessen und die Nachweisempfindlichkeit quantitativ ermittelt. Bei kleinen Implantationsdosen zeigt sich eine gute Übereinstimmung der gemessenen Profile mit den theoretischen Berechnungen.

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SIMS analysis of hydrogen in Si samples

Summary In order to optimize the hydrogen analysis in solids, systematic SIMS investigations on H and D implanted Si samples were made. Depth profiles obtained under different experimental conditions were discussed, sputtering yields and detection limits were determined. For low implantation doses the measured depth profiles are in good agreement with theoretically determined distributions.

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