Muon reconstruction and the search for leptoquarks at LHC

This diploma thesis focuses on the reconstruction of high-energetic muons. This simulation study was performed within the ATLAS experiment at the Large Hadron Collider (LHC) which is a pp-collider with a centre-of-mass energy p s = 14 TeV. The purpose of this study was to identify muons with strongly overestimated transverse momentum using Monte Carlo simulated data which has been generated using Pythia and run through a full detector simulation. These muons can lead to a faked leptoquark signal, as leptoquark-decays can include high-energetic muons. If leptoquarks exist, only a small number of such events is expected which makes the safe momentum measurement a crucial point. To achieve an optimal reconstruction, selection criteria have been developed which compare the track’s 2, the particle’s -direction and the reconstructed pT s from the different reconstruction algorithms, namely the inner detector standalone reconstruction, the muon spectrometer standalone reconstruction and a combination of both. The selection criteria are used to decide which reconstruction is chosen for a given muon. By using this selection method – contrarily to applying a cut – no events are thrown away. As a result the selection reduces the number of misreconstructed muon pT s which leads to a lower background and hence to a higher probability of identifying real leptoquark events.