[en] The authors describe the results of work with the particle detectors UA1 and UA2 at CERN, and just under 100 events. The states of Z particles observed are given and examples of Z⁰ → e⁺ + e^- and Z⁰ → e⁺ + e^- + γ are shown in the form of diagrams. They report that all events occur around the average value and that the spectral mass is, as expected theoretically, background-free, and it is intended to continue the work by determining the duration of Z as the width of the observed resonance. (H.J.P.)

[en] The coherent reactions pd→pdπ⁺π^-, pd→pdπ⁺π^-π⁰ and pd→ndπ⁺π⁺π^- are studied. In the two first reactions strong production of Δ⁺⁺(1236) is observed. Production of d*⁰ and d*⁺ is observed in the first and second reactions respectively. The forward slope of the t-distribution of the pπ⁺π^- system in the pd→pdπ⁺π^- channel decreases with increasing mass. The 1500 and 1700 MeV enhancements in the pπ⁺π^- mass spectrum of this channel are studied. Assuming that the Gribov-Morrison rule holds, it is found that by analysing the moments of the decay angular distributions that the resonances N(1470), N(1520) and N(1688) are the most likely resonances to be identified with these enhancements. Evidence is found against s-channel helicity conservation and some evidence against t-channel helicity conservation. The decay parameters of the Δ⁺⁺(1236) in the reaction pd→Δ⁺⁺π^-d are in good agreement with the predictions of a one-pion exchange model. (Auth.)

[en] In late 1981 collisions between protons and antiprotons with a combined energy of 540 GeV were observed for the first time. The particles are accelerated in the Super Proton Synchrotron (SPS) at CERN. A number of experiments are taking place. This article describes the aims, the equipment and the first results from the experiment labeled UA2 which is designed to search for W⁺, W^- and Z⁰. (J.H.)

[en] The authors report the observation of double jets in the proton-antiproton experiment at CERN SPS. A brief discussion of the mass of the jets is presented. (G.T.H.)

[en] The authors report on the UA1 and UA2 experiments at CERN to discover the W boson. Several signatures of the W have been found, from which an estimate of its mass (approx. 80 GeV) has been determined. (G.T.H.)

[en] New data on the reactions pp→pprho⁰, pn→pnrho⁰ and pn→pprho^- and new data on the reactions pp→ppf⁰ and pn→ppf⁰ at 19 GeV/c are used to study the reactions NN→NNrho and NN→NNf⁰ in terms of isospin amplitudes. The results are compared to the results of a previous analysis of single pion production in pN-collisions at the same energy. Contrary to the pion case, where the isoscalar amplitude was dominating, no amplitude dominated rho production at 19 GeV/c. Available data at other energies are used to study the energy dependence of the amplitudes. (Auth.)

[en] The coherent reactions pd→pdπ⁺π^-, pd→pdπ⁺π^-π⁰ and pd→ndπ⁺π^- are studied at 19 GeV/c. In the two first reactions strong production of Δ²⁺(1236) is observed. Some rho and ω production is seen in the second reaction. Production of d*⁰ and d*⁺ is observed in the first and second reactions respectively. Clear enhancements are seen at 1500 and 1700 MeV in the pπ⁺π^- mass spectrum of the pd→pdπ⁺π^- channel. From an analysis of the moments of the decay angular distributions of the pπ⁺π^- system it is found that the most important contributions to the 1450 and 1700 MeV structures come from spin 3/2 and spin 5/2 states respectively. Evidence is found against s-channel helicity conservation and some evidence against t-channel helicity conservation. (Auth.)

[en] Cross sections for coherent and non-coherent production of one, two and three pions in pd reactions at 19 GeV/c are presented. The mass distribution of the two pion non-coherent channels are studied. Strong single Δ(1236) and also some double Δ production are observed. Clear evidence for rho production is seen. (Auth.)

No abstract available

No abstract available