Photoproduction of pions and properties of baryon resonances from a Bonn-Gatchina partial wave analysis

Masses, widths and photocouplings of baryon resonances are determined in a coupled-channel partial wave analysis of a large variety of data. The Bonn-Gatchina partial wave formalism is extended to include a decomposition of t- and u-exchange amplitudes into individual partial waves. The multipole transition amplitudes for $\gamma p\to p\pi^0$ and $\gamma p\to n\pi^+$ are given and compared to results from other analyses.Comment: 18 pages, 14 figure

P-wave excited baryons from pion- and photo-induced hyperon production

We report evidence for $N(1710)P_{11}$, $N(1875)P_{11}$, $N(1900)P_{13}$, $\Delta(1600)P_{33}$, $\Delta(1910)P_{31}$, and $\Delta(1920)P_{33}$, and find indications that $N(1900)P_{13}$ might have a companion state at 1970\,MeV. The controversial $\Delta(1750)P_{31}$ is not seen. The evidence is derived from a study of data on pion- and photo-induced hyperon production, but other data are included as well. Most of the resonances reported here were found in the Karlsruhe-Helsinki (KH84) and the Carnegie-Mellon (CM) analyses but were challenged recently by the Data Analysis Center at GWU. Our analysis is constrained by the energy independent $\pi N$ scattering amplitudes from either KH84 or GWU. The two $\pi N$ amplitudes from KH84 or GWU, respectively, lead to slightly different $\pi N$ branching ratios of contributing resonances but the debated resonances are required in both series of fits.Comment: 22 pages, 28 figures. Some additional sets of data are adde

Properties of baryon resonances from a multichannel partial wave analysis

Properties of nucleon and $\Delta$ resonances are derived from a multichannel partial wave analysis. The statistical significance of pion and photo-induced inelastic reactions off protons are studied in a multichannel partial-wave analysis.Comment: 12 pages, 8 Table

Metal complexes with alizarin complexone AC: Electronic absorption spectra and ligand structure

The character of the electronic absorption spectra of metal complexes with alizarin complexone AC is determined by the ionization degree of the ligand and the ratio between its excited states with different contributions of tautomeric 9,10-, 1,10-, 2,9-, and 1,2-anthraquinoid resonance structures. It was found by the spectrophotometric, quantum-chemical, and correlation methods that the ligand in metal complexes can exist in three forms, namely, neutral and two ionized forms (containing one or two deprotonated hydroxy groups). For each of the latter two forms, four excited states with the dominating contribution of the 9,10-, 1,10-, 2,9-, or 1,2-anthraquinoid resonance structures are possible. The formation of red monometallic complexes involves the peri- or ortho-hydroxycarbonyl group in anthraquinoid tautomers (mostly, 1,2- and 2,9-structures). The color of bimetallic complexes is determined by four anthraquinoid structures of the ligand (from red 9,10- to blue 1,10-anthraquinones). Fluorine-containing complexes exist only as 1,2- and 1,10-anthraquinoid structures, which are responsible for their blue color. The known metal complexes with Alizarin Complexone AS were classified by their structures

Metal complexes with alizarin complexone AC: Electronic absorption spectra and ligand structure

The character of the electronic absorption spectra of metal complexes with alizarin complexone AC is determined by the ionization degree of the ligand and the ratio between its excited states with different contributions of tautomeric 9,10-, 1,10-, 2,9-, and 1,2-anthraquinoid resonance structures. It was found by the spectrophotometric, quantum-chemical, and correlation methods that the ligand in metal complexes can exist in three forms, namely, neutral and two ionized forms (containing one or two deprotonated hydroxy groups). For each of the latter two forms, four excited states with the dominating contribution of the 9,10-, 1,10-, 2,9-, or 1,2-anthraquinoid resonance structures are possible. The formation of red monometallic complexes involves the peri- or ortho-hydroxycarbonyl group in anthraquinoid tautomers (mostly, 1,2- and 2,9-structures). The color of bimetallic complexes is determined by four anthraquinoid structures of the ligand (from red 9,10- to blue 1,10-anthraquinones). Fluorine-containing complexes exist only as 1,2- and 1,10-anthraquinoid structures, which are responsible for their blue color. The known metal complexes with Alizarin Complexone AS were classified by their structures