Richard Nickerson

Abstract:

An optical data transmission system based on LED/fibre/PIN diodes is described. This system is suitable for the read out of data from the ATLAS SemiConductor Tracker (SCT). The elements of the system are described and results are given for the performance of a complete chain. The system will be used for beam tests of SCT detector modules. Adaptations of the prototype planned for the production system are discussed.

Abstract:

The diffractive production of ρ0(770) mesons in muon-proton interactions is studied in the kinematic region 0.15 GeV2 < Q2 < 20 GeV2 and 20 GeV < v < 420 GeV. The data were obtained in the Fermilab fixed-target experiment E665 with primary muons of 470 GeV energy. Results are presented on the Q2, x and v dependence of the cross section, on the shape of the π+π- mass spectrum, on the slope of the diffraction peak and on the production and decay angular distributions of the ρ0(770). The cross section for diffractive production of ρ0 by virtual photons on protons depends mainly on Q2. At fixed Q2, no significant dependence on x or v is observed. The extrapolation to Q2 = 0 yields a photoproduction cross section of (10.30 ± 0.33) μb. The slope of the t′ distribution has a value of (7.0 ± 0.2) GeV-2, with a tendency to decrease as Q2 increases. The production and decay angular distributions of the ρ0 depend strongly on Q2 and are consistent with s-channel helicity conservation. The ratio R = σL/σT deduced from the decay angular distributions rises strongly with Q2, passing the value of 1 at Q2 ≈ 2 GeV2. © Springer-Verlag 1997.

Abstract:

Using data from the Fermilab fixed target experiment E665, general properties of forward produced charged hadrons in μp interactions at a primary muon energy of 470 GeV are investigated. The normalized inclusive single-particle distributions for Feynman-x D(xF) and for the transverse momentum D(pt2, xF) are measured as a function of W and Q2. The dependence of the average transverse momentum squared 〈pt2〉 on xF, W and Q2 is studied. The increasing contribution from diffractive production as Q2 decreases leads to a reduction of the average charged hadron multiplicities at low (positive) xF and an enhancement at large xF, for Q2 ≲ 10 GeV2. It also reduces 〈pt2〉 for Q2 ≲ 5 GeV2 and 0.4 ≲ xF < 1.0. © Springer-Verlag 1997.

Abstract:

Many different configurations of electronics and semiconductor strip detectors were studied in 1995 using the ATLAS tracking detector test area at the H8 beam-line of the CERN SPS. A significant fraction of these investigations are presented elsewhere in this volume and this paper will concentrate on the results with silicon strip detectors read out with electronics preserving the pulse height information. Data has been collected with the ADAM, APV5 and FElix read-out chips on a number of different detectors. The first results are presented for read out with LHC electronics of detectors to the ATLAS-A specification of 112.5 μm pitch, employing n-strips in n-type silicon, capacitive coupling and intermediate strips. It is demonstrated that with adequate signal/noise, a spatial resolution of ≃13 μm is attainable with these detectors.