P. Mättig

Investigation of design parameters for radiation hard silicon microstrip detectors

Abstract In the context of the development of radiation hard silicon microstrip detectors for the CMS Tracker, we have investigated the dependence of interstrip and backplane capacitance as well as depletion and breakdown voltage on the design parameters and substrate characteristics of the devices. Measurements have been made for strip pitches between 60 and 240 μm and various strip implants and metal widths, using multi-geometry devices, fabricated on wafers of either 〈1 1 1〉 or 〈1 0 0〉 crystal orientation, of resistivities between 1 and 6 kΩ cm and of thicknesses between 300 and 410 μm . The effect of irradiation on properties of devices has been studied with 24 GeV /c protons up to a fluence of 4.3×10 14 cm −2 .

A study of the reaction π−p → φφn AT 16 GeV/c

Abstract The reaction π − p → φφ n has been isolated at 16 GeV/ c and its cross section determined to be 40 ± 10 nb. The φφ mass spectrum shows a threshold enhancement between 2.1 and 2.5 GeV. A successful description of the angular content of the φφ system requires two interferingss J P = 2 + states.

Final state photon bremsstrahlung ine+e−→Z0→hadrons as a tool for a precise measurement of the weak quark couplings

AbstractWe discuss for the processe+e−→Z0→q

Observation in the K+K− system of a new structure at 2.20 GeV

\bar q

Study of radiation damage and substrate resistivity effects from beam test of silicon microstrip detectors using LHC readout electronics

how final state photons can be used to disentangle the weak couplings of up and down type quarks. Since the flavour composition of multihadronic events with final state photons is different from that of all multihadrons, a combination of observables from the two samples allows the couplings to be determined. Both theZ0 width and the forward-backward charge asymmetry at centre-of-mass energies aroundMZ0 can be used to constrain the weak couplings. Taking into account the theoretical uncertainties a precision for the sum of the square axial and vector couplings of δ(v2+a2)∼4% for up and down type quarks separately seems feasible for 106Z0s. The precision from asymmetry measurements will be less significant.

A high statistics search for the ppφ− mass enhancement at 2.95 GeV

Abstract Inclusive φ production is studied in π − p collisions at 16 GeV/ c . The φ cross section for Feynman variable x φ > 0.2 is found to be (15.5 ± 3.6) μb. This leads to an extrapolated cross section of (29.9 ± 7.0) μb for x φ > 0.0. Fitting the momentum transfer squared distribution of the φ to the form e −bp 2 T gives an average slope of b = (2.4 ± 0.3) (GeV/ c −2 for x φ > 0.5.

The hardware of the ATLAS Pixel Detector Control System

Abstract A sample of 56 909 events of the reaction π − p→K + K − n at 10 GeV/ c has been measured in the Omega Spectrometer at CERN. In the K + K − system, besides production of mesons in the S ∗ /φ, f 0 / A 2 , g /ω ∗ and h regions we observe a new structure at 2.20 GeV with a width of the order of 200 MeV.

First experiences with the ATLAS pixel detector control system at the combined test beam 2004

The first upgrade for the ATLAS Pixel Detector will be an additional layer, which is called IBL (Insertable B-Layer). To readout this new layer, built from new electronics, an update of the readout electronics is necessary. The aim is to develop a system which is capable to read out at a higher bandwidth, but also compatible with the existing system to be integrated into it. This paper describes the necessary development to reach a new readout system, concentrating on the requirements of a newly designed Back of Crate card as the optical interface in the counting room.