Improved limit on the rate of the decay K+ --> pi(+)&mgr;(+)e(-)

We report results of a search for the lepton-family number violating decay K+-->pi(+)&mgr;(+)e(-) from data collected by experiment E865 in 1996 at the Alternating Gradient Synchroton of Brookhaven National Laboratory. We place an upper limit on the branching ratio at 3.9x10(-11) ( 90% C.L.). Together with results based on data collected in 1995 and an earlier experiment, E777, this result establishes a combined 90% confidence level upper limit on the branching ratio at 2.8x10(-11). We also report a new upper limit on the branching ratio for pi(0)-->&mgr;(+)e(-) of 3.8x10(-10) ( 90% C. L.).     

Time-resolved studies of deuteron beams emitted from a plasma focus

Fast (0.3—2.5 MeV) deuterons are registered with scintillator-photomultiplier detectors placed behind a Thomson analyzer. Time delays of deuteron signals (minimum FWHM ? 8 ns) in relation to X-ray signals are consistent with times of flight and show that the ions are emitted with a jitter smaller than 5 ns. Longer multi-spike ion pulses sometimes observed are interpreted.     

Problems arising in the development of optical communication systems

The report starts with a survey of methods and feasibilities for the application of optical transmission systems in present and in future communication networks. Transmission systems with 1.12 Gbit/s offer new prospects for developing integrated communication systems. Therefore for this bitrate the use of optical components and the attainable repeater distances are discussed in detail. Finally an experimental model of an integrated broadband network is presented allowing to study the unsolved problems of using optical transmission channels in complex transmission and switching systems.     

Über die Nullstellen der Ableitung der Lösungen linearer Differentialgleichungen 2. Ordnung

Ohne ZusammenfassungDiese Arbeit ist ein Teil meiner von der Naturwissenschaftlichen Fakultät der Universität Würzburg angenommenen Habilitationsschrift. Der Deutschen Forschungsgemeinschaft danke ich für die Gewährung eines Habilitandenstipendiums.     

EPR-studies on the chelation of alkali metal cations by radical-anions—IV Radical-anions derived from 1,2,4,5-tetramesitoybenzene

1,2,4,5-Tetramesitoylbenzene was synthesized and reduced with alkali metals as well as electrolytically. EPR spectra of the resulting radical-ion pairs are reported and discussed. The electron-spin densities obtained from temperature coefficient and marked solvent dependency. These effects are compared with the ones observed in the corresponding radical-ion pairs of o-dimesitoylbenzene for which some new data are also reported.     

Precise Measurement of Muon Capture on the Proton

The aim of the μCap experiment is a 1% measurement of the singlet capture rate Λ _S for the basic electro-weak reaction μ + p → n + ν_μ. This observable is sensitive to the weak form-factors of the nucleon, in particular to the induced pseudoscalar coupling constant g _P . It will provide a rigorous test of theoretical predictions based on the Standard Model and effective theories of QCD. The present method is based on high precision lifetime measurements of μ⁻ in hydrogen gas and the comparison with the free μ⁺ lifetime. The μ⁻ experiment will be performed in ultra-clean, deuterium-depleted H₂ gas at 10 bar. Low density compared to liquid H₂ is chosen to avoid uncertainties due to ppμ formation. A time projection chamber acts as a pure hydrogen active target. It defines the muon stop position in 3D and detects rare background reactions. Decay electrons are tracked in cylindrical wire-chambers and a scintillator array covering 75% of 4π. This revised version was published online in August 2006 with corrections to the Cover Date.