Prof Dr Armin Reichold

Abstract:

We present a measurement of the tt̄ production cross section using events with one charged lepton and jets from pp̄ collisions at a center-of-mass energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb^-1 of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5 ± 1.8 events are expected from background contributions. We measure a tt̄ production cross section of 5.6-1.1^+1.2(stat.)-0.6^+0.9(syst.) pb. © 2005 The American Physical Society.

Abstract:

The design and technology of the silicon strip detector modules for the Semiconductor Tracker (SCT) of the ATLAS experiment have been finalised in the last several years. Integral to this process has been the measurement and verification of the tracking performance of the different module types in test beams at the CERN SPS and the KEK PS. Tests have been performed to explore the module performance under various operating conditions including detector bias voltage, magnetic field, incidence angle, and state of irradiation up to 3×1014 protons per square centimetre. A particular emphasis has been the understanding of the operational consequences of the binary readout scheme. © 2004 Elsevier B.V. All rights reserved.

Abstract:

We present the results of a search for anomalous production of diphoton events with large missing transverse energy using the Collider Detector at Fermilab. In 202 pb -1 of pp̄ collisions at √s = 1.96 TeV we observe no candidate events, with an expected standard model background of 0.27 ± 0.07(stat) ± 0.10(syst) events. The results exclude a lightest chargino of mass less than 167 GeV/c 2, and lightest neutralino of mass less than 93 GeV/c 2 at 95% C.L. in a gauge-mediated supersymmetry-breaking model with a light gravitino. © 2005 The American Physical Society.

Abstract:

To reach design luminosity, the International Linear Collider (ILC) must be able to create and reliably maintain nanometer size beams. The ATF damping ring is the unique facility where ILC emittances are possible. In this paper we present and evaluate the proposal to create a final focus facility at the ATF which, using compact final focus optics and an ILC-like bunch train, would be capable of achieving 37 nm beam size. Such a facility would enable the development of beam diagnostics and tuning methods, as well as the training of young accelerator physicists. © 2005 IEEE.