Licentiate Thesis: Identification of Stable Massive Particles with the Tile Calorimeter and Monitoring of the LHC Beams and Timing Signals at ATLAS

by Christian Ohm (Stockholm University, Department of Physics)

Friday 11 Dec 2009, 14:00 → 16:00 Europe/Stockholm

FB51

Around the time of the defense of this thesis, the ATLAS experiment at CERN is expected to study the first proton-proton collisions created by the Large Hadron Collider, after over 15 years of design, development, construction, testing and commissioning. ATLAS will study the smallest constituents of matter and the fundamental forces that govern their interactions in search of new physics in an unprobed energy regime. In order to do this, it is absolutely crucial that the subdetectors in ATLAS are well calibrated in time, and this thesis summarizes work on two very different aspects of timing in ATLAS. The first two papers describe how electrostatic beam pick-up detectors have been exploited to build a monitoring system for the LHC beams and timing signals, and a beam-related input to the ATLAS trigger system. Results from a period of single-beam running in 2008 are presented, and the performance of the system is evaluated. The third paper presents a method developed to measure the time-of-flight of particles produced in the proton-proton collisions, and explains how it will be used to search for stable massive particles that are predicted in models of supersymmetry and extra dimensions. The method is evaluated using Monte Carlo simulations and the predicted speed and mass resolutions are presented.