Search

The angular distributions of the reactione+e−→μ+μ− ande+e+→τ+τ− have been measured between and 60.8 GeV with the VENUS detector at TRISTAN. The average total cross section and the forward-backward charge asymmetry for μ-pair production are observed to be 28.3±1.4±0.8 pb and (−29.0−4.8+5.0±0.5)%, and those for τ-pair production are 27.6±1.7±1.0 pb and (−32.8−6.2+6.4±1.5)% at . These values are consistent with the predictions of the standard model of electroweak interactions.

Performances of limited streamer tubes operated with nonflammable gas mixtures composed of argon (Ar), carbon-dioxide (CO 2 ) and isobutane (i-C 4 H 10 ) with ratios of 1:1.5:0.15, 1:2:0.2, 1:3:0.3, 1:4:0.4 and 1:6:0.6 were studied. It was found that these mixtures were very suitable for the VENUS detector. The charge spectra exhibited very sharp distributions and indicated the possibility for the limited streamer tubes to be applied to calorimetry use. A mixture of 1:2:0.2 was chosen for the VENUS streamer tubes because of its moderate gain and long efficiency plateau.

The relationship between structure and intrinsic knockdown potency against house flies, measured under synergistic conditions with metabolic inhibitors, was examined quantitatively for three series of chrysanthemic acid esters. The first series was tetramethrin and related N-methylol esters and the second and third were meta- and para-substituted benzyl esters, respectively. The three-dimensional quantitative structure-activity relationship was examined by comparative molecular field analysis (CoMFA). All three series of compounds could he analyzed by steric-field descriptor terms. For two of the three series, hydrophobicity improved the correlation when used as an additional variable. The results were consistent with our previous quantitative analyses done with free-energy-related substituent and submolecular parameters and the traditional regression procedure. Variations in the knockdown potency of all three series taken together, with their different skeletal structures of the alcohol moiety, could be analyzed by CoMFA with the steric- and electrostatic-field descriptor terms. The additional use of the hydrophobicity descriptor did not improve correlation for the combined set, perhaps because of multiple collinearity among the hydrophobicity parameter and steric- and electrostatic-field descriptors.Copyright 1994, 1999 Academic Press

Abstract: Differential cross sections fore + e –$$e^ + e^ - \to \tilde \gamma \tilde \gamma $$ . No candidate events were found and a new limit on the photino mass is obtained.