Professor Tony Weidberg

Abstract:

The “APC3” is a charge sampling and storage chip designed for high speed readout of silicon detectors. It has 32 channels, each with preamplifier, integrator and storage capacitors. Current from a silicon detector connected to the input is integrated as a charge and stored on a capacitor. There are 128 capacitors per channel which are used sequentially to store the charge. The charge is held on the storage capacitor until it is either read out or discarded. Logic on the chip manages the storage and retrieval of samples. This logic uses a novel architecture based on a system of pointers and read out addresses. This paper describes the operation of the chip and measurements of its performance. © 1994 IEEE

Abstract:

This paper discusses some of the problems of triggering at a high energy, high luminosity pp collider. A suggested second level track trigger for the ATLAS detector is described, based on hit information from a silicon tracker. Detailed Monte Carlo simulations have been performed to assess the performance of the trigger in accepting electrons and in rejecting the QCD jets that would fake electrons in the first level calorimeter trigger. Studies of the feasibility of implementing such a trigger are also presented. © 1993.

Abstract:

The two-jet invariant mass spectrum as measured in the UA2 experiment is used to search for additional heavy vector bosons decaying to two-jets. The mass of an additional W boson that couples to fermions with a V+A form is constrained to be greater than 261 GeV to the 90% confidence level. A limit on the production cross section of additional W and Z bosons is given as a function of the boson mass. A limit on the production of excited quarks is also given as a function of the excited quark mass. © 1993.