Search

32 pp. (1977).

(1978). doi:10.1007/BF02734201, We present numerical estimates for the radiative corrections to the decays L∓ → e∓νeνL, μ∓ νμνL in the context of aV ±A interaction. The radiative corrections change the Michel parameter appreciably from its bareV ±A value, for the decay L∓ → e∓νeνL, and have a measurable effect on the electron energy spectrum.

(1977). doi:10.1016/0370-2693(77)90292-1, We have measured inclusive muon production in e + e − annihilation for CMS energies between 3.6 and 5.0 GeV. Above 4 GeV the cross section cannot be explained by conventional sources like higher order QED processes or inclusive production of the J ϑ (3.1). It is, however, compatible with the pair production of heavy particles of a mass of about 1.9 GeV/ c 2 . Spin assignment and decay parameters are investigated.

(1979). doi:10.1007/BF01445408, The contributions from two QED processes,e+e− →μ+μ−γγ ande+e− →μ+μ−, to the heavy lepton signal observed in muon inclusive final states ine+e− annihilation are calculated for the experimental setup of PLUTO in the energy range 4–5 GeV. Some modifications in the usual calculation techniques for QED processes are described. We discuss the observability of the sequential heavy lepton signal at PETRA energies and show which experimental cuts sufficiently damp the background to signal ratio.

(1978). doi:10.1016/0370-2693(78)90183-1, The cross sections for e + e − → e + ( μ + + non showering track + any photons have been measured for cm energies between 3.1 GeV and 5.2 GeV. We observe τ -pair production below the thresholdfor charm production and determine the τ mass to be 1.807 ± 0.020 GeV from a fit to the energy dependence of the cross section. The ration of the leptonic branching ratios B μ / B e = 0.92 ± 0.32 is consistent with eμ-universality. The following branching ratios are determined for a V-A coupling: B(τ → ν τ e ν ) = B(τ → ν τ μ ν ) = 0.182 + 0.028 . B ( τ → ν τ + charged hadron + any photons) = 0.29 ± 0.11, B ( τ → ν τ + three or more charged hadrons + any photons) = 0.35 ± 0.11.

(1977). doi:10.1016/0370-2693(77)90293-3, Events of the type e + e − →μ ± +e ∓ + “nothing” have been observed in the magnetic detector PLUTO at the storage ring DORIS at DESY. The data support the hypothesis of the pair production of heavy leptons, and allow to determine decay parameters. Decay rates into muons and electrons are equal within error, and argue for a new lepton number of the heavy lepton.