[en] The characteristics and the performances of a gas spring, to be used in the future in a three-dimensional multiple attenuation system, designed to support the heavy test masses for a low-frequency gravitational wave interferometric antenna, are presented. This multiple system is expected to attenuate 10^-9 (10^-11) at 10 Hz in the vertical (horizontal) direction. This experiment, in which masses up to 430 kg have been levitated, has shown that the height of the resonance peaks in the gas spring vertical and horizontal transfer functions should not prevent us from obtaining the required high attenuation factors. A gas temperature feedback system, for the gas volume control, has given satisfactory results

[en] The construction of a full scale prototype shower counter for the FNAL Collider Detector Facility central calorimetry is described in detail. Beam tests provide results on performance parameters. (orig.)

[en] An event representing the production and decay of the charmed F⁺ meson has been identified by means of a 3-constraint fit to the decay hypothesis F⁺ → π⁺π^-π⁰, in which both γ-rays from the π⁰ converted. The event was produced by a charged current vsub(μ) interaction in an emulsion stack located inside the Fermilab 15-foot bubble chamber. The F⁺ traveled 50 μm, corresponding to a proper time of 1.4 x 10^-13 seconds, before decaying in flight. Its mass was determined to be 2017 +- 25 MeV. (orig.)

[en] Any event representing the production and decay of the charmed F⁺ meson has been identified by means of a 3-constraint fit to the decay hypothesis F⁺→π⁺π⁺π^-π⁰, in which both γ-rays from the π⁰ converted. The event was produced by a charged current ν/sub μ/ interaction in an emulsion stack located inside the Fermilab 15-foot bubble chamber. The F⁺ traveled 50 μm, corresponding to a proper time of 1.4 x 10^-13 seconds, before decaying in flight. Its mass was determined to be 2017 +- 25 MeV

[en] The CDF central and endwall hadron calorimeter covers the polar region between 30⁰ and 150⁰ and a full 2π in azimuth. It consists of 48 steel-scintillator central modules with 2.5 cm sampling and 48 steel-scintillator endwall modules with 5.0 cm sampling. A general description of the detector is given. Calibration techniques and performance are discussed. Some results of the test beam studies are shown. (orig.)

[en] The central electromagnetic calorimeter for the Collider Detector at Fermilab uses a hybrid design with scintillator and wavelength shifter for energy measurement and an embedded strip chamber for position determination and longitudinal shower development. Complementary calibration systems are incorporated in the design. Calorimeter characteristics and performance are summarized. An average energy resolution, σ(E)/E, of 13.5%√(E sin θ) (with E in GeV), and a position resolution of ±2 mm at 50 GeV are measured. (orig.)

[en] The status of advancement of the VIRGO Project is presented: the first-generation results from the Pisa seismic noise super attenuator give an upper limit to the noise transfer function of 2x10^-8 at 10 Hz. The upper limit to the absolute noise of the 400 kg test mass at 10 Hz has been measured to be 1.5x10^-13 m/√Hz. The scheme and the related problems of the VIRGO interferometer, which is supposed to work down to 10 Hz, are also presented. At the 3rd Pisa Meeting in 1986 we presented the idea of what could be a very efficient seismic noise reduction system able to give a sensitivity h∝10^-25 at 10 Hz, in a 3 km interferometer for 1 year integration time. Now we have two new facts to present: the first is that the attenuator has been built, is working in Pisa, and shows remarkable characteristics. The second is the Italian-French interferometer VIRGO, a 3 km long antenna for low and high frequency (10-1000 Hz) gravitational wave (GW) detection. These two items will be presented in this article. (orig.)