Admittance of Pentacene- Based Mis-Structures with Two-Layer Insulator SiO2–Al2O3

Russian Physics Journal - Experimental studies of the admittance of MIS structures based on pentacene with a two-layer insulator SiO2–Al2O3 and back contacts made of various materials (Au,...     

Special Features of Photo- and Electroluminescence of Zinc and Magnesium Complexes

Russian Physics Journal - The results of spectral and luminescent study of zinc and magnesium metal complexes are presented. It is shown that radiation in mixed ligand complexes has the charge...     

Admittance of Organic LED Structures with an Emission YAK-203 Layer

Russian Physics Journal - The current-voltage characteristics and admittance of multilayer structures for organic LEDs based on the PEDOT:PSS/NPD/YAK-203/BCP system have been experimentally...     

Search for the Theta+ Pentaquark in the gammad--> DeltanK+ reaction measured with the CLAS spectrometer

For the first time, the reaction gammad-->DeltanK+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Laboratory, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant-mass distribution. The upper limit on the gammad-->DeltaTheta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.     

Chiral invariant phase space event generator

An event generator based on the CHIPS model is implemented in the GEANT4 simulation toolkit. Nuclear fragment production in the process of pion capture on nuclei is used to tune the parameters of the CHIPS model describing clusterization of nucleons in nuclei. The spectra of nucleons and nuclear fragments in pion capture and in photonuclear reactions at 60 MeV are compared with experimental data. Received: 30 May 2000 / Accepted: 2 November 2000     

Chiral invariant phase space event generator

The CHIPS model and its first implementation within the GEANT4 simulation software package are considered. Hadron production in the process of nucleon-antinucleon annihilation is used as the basic example showing the structure of the model and corresponding software modeling algorithms. Model calculations of multiplicities and spectra of secondary hadrons in the annihilation process are compared with experimental data.     

Observation of an exotic S = +1 baryon in exclusive photoproduction from the deuteron

In an exclusive measurement of the reaction gammad-->K(+)K(-)pn, a narrow peak that can be attributed to an exotic baryon with strangeness S=+1 is seen in the K(+)n invariant mass spectrum. The peak is at 1.542+/-0.005 GeV/c(2) with a measured width of 0.021 GeV/c(2) FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is (5.2+/-0.6)sigma. The mass and width of the observed peak are consistent with recent reports of a narrow S=+1 baryon by other experimental groups.     

First measurement of transferred polarization in the exclusive ep-->e'K+Lambda--> reaction

The first measurements of the transferred polarization for the exclusive e-->p-->e(')K+Lambda--> reaction have been performed at Jefferson Laboratory using the CLAS spectrometer. A 2.567 GeV beam was used to measure the hyperon polarization over Q2 from 0.3 to 1.5 (GeV/c)(2), W from 1.6 to 2.15 GeV, and over the full K+ center-of-mass angular range. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A nonrelativistic quark-model interpretation of our data suggests that the ssmacr; quark pair is produced with spins predominantly antialigned. Implications for the validity of the most widely used quark-pair creation operator are discussed.