[en] A system of large planar proportional chambers has been built in the Mechanical Workshop of NIKHEF-H, Amsterdam. The chambers were used to provide coordinate data for on-line track reconstruction using the FAMP system in the NA11 experiment at CERN. The system was first used as an effective mass trigger for a high statistics inclusive phi experiment. In this report, the design, construction and performance of the chambers, with its associated read-out system is described. (Auth.)

[en] In the experiment NA11 at the CERN SPS the MC68000 based FAMP system has been successfully implemented in a second stage trigger. It was used in a study of inclusive phi-meson production to select phi → K⁺K^- decays by determining the charged K-meson trajectories and calculating the K⁺K^- invariant mass. A trigger rate reduction by a factor of 25 and an increase in the number of recorded phi-decays per unit time by a factor of 8 has been achieved. (Auth.)

[en] In the experiment NA11 at the CERN SPS the MC68000 based FAMP system has been successfully implemented in a second stage trigger. It was used in a study of inclusive phi-meson production to select phi->K⁺K^- decays by determining the charged K-meson trajectories and calculating the K⁺K^- invariant mass. A trigger rate reduction by a factor of 25 and an increase in the number of recorded phi-decays per unit time by a factor of 8 has been achieved. (orig.)

[en] A search for the S(1936) has been made in the invariant mass spectrum of anti pp-pairs produced inclusively in proton-beryllium interactions at 100 GeV incident momentum. No enhancement is observed, giving a 3 standard deviation upper limit on the cross section of 220 nb/nucleon for production of a narrow anti pp state around approx. 1940 MeV in the xsub(F) range 0.18 < xsub(F) < 0.48. (orig.)

[en] The ZEUS collaboration is building a system to monitor, control and document the hardware of the ZEUS detector. This system is based on a network of VAX computers and microprocessors connected via ethernet. The database for the hardware values will be ADAMO tables; the ethernet connection will be DECNET, TCP/IP, or RPC. Most of the documentation will also be kept in ADAMO tables for easy access by users. (orig.)

[en] The first three years' running experience of the ZEUS trigger system is reviewed. A three level trigger system was built to cope with the high frequency collisions and the high background rates. In 1994 the design performance was almost achieved at each level. The system is flexible enough to match the physics needs that change with increasing luminosity. (orig.)

[en] The A-dependence of the inclusive phi meson cross-section is measured using two target materials, beryllium and tantalum, in the kinematic range 0< xsub(F)<0.3 and psub(T)²<1 GeV². Parametrizing the cross-section with sigma(A)=sigma(A=1) Asup(α), yield α=0.90+-0.02 and α=0.86+-0.02 for production of phi's with 120 GeV π⁺ and p-beams respectively. (orig.)

[en] In this paper some characteristics of two-phi production are investigated for different incident particles and compared with single-phi production, thus allowing some qualitative conclusions concerning the production process. The production of phi-meson pairs is studied, as a result of different hadron-beryllium collisions at 100 GeV/c incident momentum. The phi-mesons are identified via their K⁺0^--decay channel. The number of two-phi events is a factor 6 larger than expected for uncorrelated production of two single-phi mesons. In the 0.2-0.7 region of the Feynman-x, the cross-section ratio of the kaon-induced over the pion-induced process shows an increase with increasing Feynman-x similar to that observed for single phi production. This suggests an analogous production mechanism for single-phi and two-phi production. (Auth.)

[en] The mass-number dependence of the inclusive phi-meson cross section is measured using two target materials, beryllium and tantalum, in the kinematic range 0< xsub(F)<0.3 and psub(T)sup(2)<1 GeV². Parametrizing the cross section with sigma(A)+ and p-beams respectively. (Auth.)

[en] A search has been made for the hadronic production of charmed baryons and mesons with a large aperture forward magnetic spectrometer using 150-GeV protons originating from the CERN-SPS. A prompt electron trigger was used as a signature for charm. Upper limits at 90% Confidence Level have been obtained for the production of Λsub(c)⁺, D⁰, D-bar⁰, D⁺ and D^-: sigma(Λsub(c)) < 8 μb, sigma(D⁰) < 64 μb, sigma(D-bar⁰) < 37 μb, sigma(D⁺) < 51 μb and sigma(D^-) < 49 μb per nucleon, assuming linear A-dependence. (Auth.)