[en] The possibility to investigate the in-medium properties of the vector ω mesons at normal nuclear density is considered. The folding model and simulations with the RQMD generator have been used for studying of the ω-resonance production in Ap and pA reactions and its ω ^→ π⁰γ ^→ 3γ decay. We show that measurements in the inverse Ap kinematics is an effective way to get information about the ω-meson mass modification especially in not yet explored range of small meson momenta relative to the projectile nuclei where the strength of the effect is expected to be most strong. The traditional pA kinematics appears to be more preferable for the investigation of the in-medium ω-meson width. Using of compact electromagnetic calorimeter provides the possibility to collect large statistics and study the momentum dependencies of both the ω-meson mass and width at the density of normal nuclei.

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[en] The design and the mass production of the proportional wire chambers for the barrel part of the uranium-gas sampling hadron calorimeter of the L3 detector at the CERN Large Electron-Positron storage ring (LEP) are described. The chambers meet the specific requirements arising from the limited space available to the calorimeter, the radioactivity of uranium, and the physics criteria of good energy and position resolution for incident hadrons. The mass production techniques employed ensured that all of the 371664 chamber cells have uniform response (with 5% accuracy) to ionizing particles. Over 8000 chambers of the same design, in 53 different sizes, were manufactured and tested at the ITEP (Moscow), at the University of Michigan (Ann Arbor) and at the IHEP (Beijing). (orig.)

[en] Results of experimental studies of the performance of the uranium calorimeter with gas sampling detectors are presented. There is further evidence showing the importance of the contribution of the neutron component of a hadronic shower to the detected signal. The response and the resolution of the uranium calorimeter are measured in the momentum range 0.3-0.6 GeV/c for the different incident particles and different gases that are used in the detectors. For a calorimeter structure with double-gas-detector layers, the correlation between signals from two calorimeters formed by chambers filled with different gas mixtures is measured. The topics that are relevant to the performance of the L3 uranium-gas sampling calorimeter - such as its operation in the magnetic field, the energy dependence of muon response, the uranium noise, as well as the electronics optimization - are discussed. (orig.)

[en] The production of K⁺ and π⁺ mesons and protons in pBe collisions at T_p=2.9 GeV has been studied at the ITEP proton synchrotron. Ejectiles with a momentum of p=545 MeV/c were observed under an emission angle θ=17 . The detectors which have been developed for the identification of kaons out of a six orders of magnitude more intense background of pions and protons are described. A cross-section ratio d²σ_K⁺/dΩdp:d²σ_π⁺/dΩdp:d²σ_p/dΩdp of (1±0.34):(85±1):(31±1) has been measured. Normalization with existing pion data yields an invariant differential cross section E.d³σ_K⁺/d³p=(3.1±1.2) mb GeV^-2 c³ sr^-1 and a total cross section of σ_tot(pBe)=(3.7±1.5) mb. These cross sections are compared with existing data and theoretical predictions. The A dependence of K⁺ production in the few-GeV range is analyzed. (orig.)