109327315
Junction depth dependence of breakdown in silicon detector diodes
Abstract The high voltage capability of detector diodes fabricated in the planar process is limited by the high field generated at the edge of the junction. We have fabricated diodes with increased junction depth with respect to our standard process and find a significantly higher breakdown voltage, in reasonable agreement with previous studies of junction breakdown.
122392894
New values of pion-nucleon scattering lengths and f2
Abstract From fixed t dispersion relations we have obtained more accurate values for the pion nucleon coupling constant and s -wave scattering lengths, using our recent low energy πN angular distribution and total cross section data. The results are: f 2 = 0.0790 ± 0.0010, a 1 − a 3 = 0.262 ± 0.004 μ −1 , a 1 + 2 a 3 = − 0.014 ± 0.005 μ −1 .
116038279
New value for the sigma-commutator for $pi$N scattering
121887220
The OPAL vertex drift chamber
Abstract A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar.
109259217
FOXFET biassed microstrip detectors
Abstract A method has been developed for biassing the strips of a silicon microstrip detector with a tunable dynamic resistance. This allows the strip potentials to be tied to a fixed voltage, virtually independent of the strip leakage currents, whilst requiring no processing steps additional to those needed for a standard capacitively coupled detector. Results are presented for full sized detectors (3.3 cm × 6.0 cm) both measured on a probe station and equipped with VLSI readout (MX3) chips. Assemblies are currently undergoing beam tests at CERN with indications of very promising performance.
122579699
Evidence for a directional dependence of Bose-Einstein correlations at the CERN intersecting storage rings
Abstract In pp and pp collisions at the CERN Intersecting Storage Rings, a directional dependence of the size of the pion-emitting region is observed using Bose-Einstein interference between identical charged pions. The data reveal a substantially larger dimension in the direction parallel to the beam axis than in the transverse direction, indicating a prolate shape of the emission region. For αα interactions, the data are consistent with a spherical shape.
13865686
CP Violation in Cascade Decays of B Mesons
General techniques are introduced to expose new CP-nonconserving effects in cascade decays of B mesons. These effects are computed in the Kobayashi-Maskawa model. The CP asymmetries so obtained range from 2% to 20% if the parameters are in the favorable range s/sub 3/