G.D. Smith

A study of inclusive Λ, > Σ0 and Σ(1385) production in K−p interactions at 8.25 GeV/c

Abstract Inclusive Λ production has been studied in K−p interactions at 8.25 GeV/c using about 69 000 events; the total cross section is found to be 3.35 ± 0.20 mb. A comparison has been made with Σ0 and Σ(1385) inclusive production. Their influence on the inclusive Λ production is discussed. The inclusive Λ cross section and polarization is interpreted in terms of the triple-Regge model. In the target fragmentation region an effective Regge trajectory is determined which lies closer to the K than to the K∗. In the beam fragmentation region the cross-section data indicate an effective Regge trajectory which corresponds to the nucleon, while the polarization data require additional Regge exchanges to be present.

High density interconnect multi-chip module for the front-end electronics of the PHENIX/MVD

A multi-chip module (MCM) based on High Density Interconnect (HDI) technology was developed for the front-end electronics of a high energy nuclear physics experiment to process charge pulses from silicon detectors. Stringent requirements in performance as well as low radiation length and minimum physical size of the module dictated the use of the most sophisticated MCM technology available. The module handles 256 input channels on an alumina substrate with milled cavities for die placements and four layers of thin-film traces of 42u width. A total of 20 custom integrated circuit chips and 98 passive components are assembled on a substrate of size 43 mm/spl times/48 mm. Various aspects of development efforts for the design and fabrication as well as the electrical test results of the module are discussed.

The PHENIX Multiplicity and Vertex Detector

Abstract We describe the design and expected performance of the PHENIX Multiplicity and Vertex Detector (MVD) sub-system of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC).

Simulations of the performance of the MVD in PHENIX

The PHENIX Multiplicity Vertex Detector (MVD) provides event characterization, a centrality trigger, collision vertex position, and measures fluctuations in charged particle multiplicities. The design criteria include a large rapidity coverage, good azimuthal coverage and granularity, minimizing material in the electron arm acceptance, and minimizing costs. The MVD contains two concentric barrels of Si strip detectors with two disk-shaped Si pad detector endcaps. Simulations show that the vertex position can be located to within a few hundred microns using hits in the barrels. A channel multiplicity signal is formed for use in the Level-1 trigger. The effect of the expected discriminator performance on this trigger signal will be shown. The pad and strip detectors are read-out with identical electronics. The influence of the performance of the electronics on the detectors performance are discussed.