Unter dem speziellen Gesichtspunkt der Verbesserung der Behandlungsergebnisse des akuten Ischämie-Syndroms der unteren Extremitäten erfolgte eine retrospektive Analyse von 344 Patienten. Eine arterielle Embolie lag in 46,4%, eine akute Thrombose in 32,7%, den akuten Verschlüssen zugrunde. In 20,9% war eine eindeutige Zuordnung der Verschlußursache nicht möglich. Das Zeitintervall zwischen Symptom und Beginn der Therapie betrug bei den Embolien in 29% und bei den Thrombosen in 41% mehr als zwölf Stunden. In 67% wurde eine transfemorale indirekte Thrombembolektomie durchgeführt. Durch den Einsatz neuerer risikoarmer Behandlungsmethoden (Aspirationsembolektomie, Lyse und PTA etc.) läßt sich das Ergebnis weiter verbessern.

We have studied the τ→νρ0π decay in data taken with the PLUTO detector at the DORISe+e− storage ring, at CM energies from 4 to 5 GeV. We have found 27 events with the τ→νρ0π decay mode corresponding to a branching ratio ofB=(5.4±1.7)%. The Dalitz plot and theρ0π mass spectrum are analysed for the ρπ partial wave and spin state. Only theρ0πs-wave as produced by the axial vector current gives a good description. Theρ0π mass spectrum is suggestive of anA1 resonance. An upper limit on τ±→vπ±π+π− withoutρ0 formation is given.

Two methods for setting an upper limit on the τ lifetime using events assigned to τ+τ- production in e+e- annihilation in the centre of mass energy range 3.9 to 5 GeV are discussed. The combined result is a 95% CL upper limit for the τ lifetime of 9.0 × 10−12.

The decay of the heavy lepton τ into πv has been established using the magnetic detector PLUTO. The branching ratio is determined to be BR(τ→πv)=(9.0 ± 2.9)% with an additional systematic uncertainty of 2.5%. This value is in good agreement with the theoretical prediction.

The J/ψ decay modes f 0 (1270)γ and ρπ have been studied in e + e − collision at 3.1 GeV center of mass energy leading to the π + π − γ and π + π − π 0 final states. The f 0 γ decay branching ratio is measured to be (0.20 ± 0.07) × 10 −2 , a value comparable to the J/ψ radiative decay rates into the ηγ and η′γ channels. The J/ψ decay branching ratio into ϱπ is measured to be (1.6 ± 0.4) × 10 −2 .

The polarization of the f0(1270) and ϱ0(770) produced in the J/ψ decays into f0γ and ϱ0π0 are measured in e+e− collisions at 3.1 GeV. A fit to the f0 production and decay angular distributions yields the values A1/A0 = 0.6 ± 0.3 and A2/A0 = 0.3 −1.6+0.6, where Aλ are the f0 helicity amplitudes. These results are in good agreement with the values predicted from a QCD two-gluon-exchange model. In addition an upper limit of 2.3 × 10−4 is obtained for the J/ψ → f′0(1514) γ decay branching ratio which implies Γ(J/ψ → f′γ)/Γ(J/ψ → f0γ) ⩽ 0.12 ± 0.05.

The J/ψ decay modes f0(1270)γ and ρπ have been studied in e+e− collision at 3.1 GeV center of mass energy leading to the π+π−γ and π+π−π0 final states. The f0γ decay branching ratio is measured to be (0.20 ± 0.07) × 10−2, a value comparable to the J/ψ radiative decay rates into the ηγ and η′γ channels. The J/ψ decay branching ratio into ϱπ is measured to be (1.6 ± 0.4) × 10−2.

Annihilation of e+e− into final states with a single electron has been studied with the PLUTO detector at the DORIS storage ring at CMS energies from 3.6 to 5 GeV. In the sample of 4-prong events without any detected photon we observe 21 events which we assign to the reaction e+e− → τ+τ− → ννe + νϱ0π. We obtain a branching ratio for τ+ → νϱ0π+ of 0.050 ± 0.015 with an overall systematic uncertainty of 30%. The data are consistent with the ϱπ coming from an A1 meson.