Zusammenstellung der deutschen Patente im Hufbeschlag

Available from: Zentralstelle fuer Agrardokumentation und -information (ZADI), Villichgasse 17, D-53177 Bonn / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

A measurement of the weak axial couplings of theb- andc-quark

The forward-backward charge asymmetries of theb andc quarks are measured with the JADE detector at PETRA at s√=35 GeV and 44 GeV using both electrons and muons to tag the heavy quarks. At s√=35 GeV, a simultaneous fit for the two asymmetries yields the resultA b =−9.3±5.2% (state.) ndA c =−9.6±4.0% (stat.). The systematic errors are comparable with the statistical uncertainties. Combining the measurements at both energies and alternately constraining the weak coupling of thec andb quark to their Standard Model values (a c =1,a b =−1) increases the precision of the measurement of coupling constant of the other quark. Using this procedurea b =−0.72±0.34 anda c =0.79±0.40, where the numbers are corrected for BBˉ−mixing and the errors include both statistical and systematic contributions. The mixing parameter for continuum bbˉ−production is determined to be χ-0.24±0.12 if both heavy quark coupling constants are constrained to their values in the Standard Model

A measurement of the τ lepton lifetime

The lifetime of the τ lepton was measured using two different techniques. From the impact parameter distribution of 3132 one prong decays ττ = (289±33±26) fs was obtained and from the decay length distribution of 648 three prong decays ττ = (309 −34 +35±11) fs. These results were combined to give a final value of ττ = (301±29) fs

A SEARCH FOR MONOJET EVENTS PRODUCED BY VIRTUAL Z0 BOSONS IN e+ e- ANNIHILATION AT PETRA

A search was performed for the associated production of two different Higgs bosons via a virtual Z0 in e+e− annihilation (e+e− → h10h20) using the JADE detector at PETRA. This was motivated by the interpretation of the monojet events observed at the CERN p collider as anomalous Z0 decays into two neutral Higgs bosons (h10 and h20), where h10 is stable and escapes detection while h20 decays into hadrons. Single- or di-jet events with large momentum imbalance are then expected at PETRA energies. No evidence for such events was found in our data; this excludes h20 masses in the range of 1 to 21 GeV with 95% CL, if the branching fraction for Z0 → h10h20 is a larger than one half that for . The possibility that the monojets could originate from supersymmetric higgsino production from Z0 decay is also examined

Measurement of two photon production of rho0 omega

The reaction γγ→π+π-π+π-π0 has been studied using the JADE detector at PETRA. The cross sections for γγ→ωπ+ - and for γγ→ωρ0 - are given. We observe no peak in these cross sections in the regionW γγ=1.9–2.0 GeV

A MEASUREMENT OF THE eta RADIATIVE WIDTH GAMMA eta ---> gamma gamma

The radiative width of the η meson has been measured at PETRA in photon-photon collisions. The resulting value is Γη→γγ=0.53±0.04±0.04 keV