In 2010, the Large Hadron Collider (\\lhc{}) at the European Organisation for Nuclear Research (CERN) near Geneva (Switzerland) came into full operation providing proton-proton collisions at a centre-of-mass energy of $\\sqrt{s} = \\unit[7]{TeV}$. \\lhc{} data may allow the observation of the Higgs boson, the last unknown building block of the standard model of particle physics (SM). Di-muon final states containing heavy flavour jets pose an irreducible background for searches of the Higgs boson as predicted the SM or theories beyond. They also provide a unique testbed for tests of perturbative Quantum Chromo-Dynamics (pQCD). This thesis provides a measurement of the cross section of events with one di-muon pair with an invariant mass in the \\Z{} mass region and at least one heavy flavour jet. Studies on acceptance and systematic effects of the experimental setup are presented as well as a comparison to theoretical predictions. The total inclusive cross section of \\zbFS{} events was observed as $\\sigma(\\mu^{+}\\mu^{-}+b+X) = \\unit[(4.15 ^{+0.97}_{-0.89} (stat.) ^{+0.45}_{-0.53} (syst.))]{pb} $ from the equivalent of $\\unit[36]{pb^{-1}}$ of data. Agreement with pQCD predictions at next-to leading order (NLO) is found while tensions with leading order (LO) predictions are observed. Further, the cross-section ratio \\RwZ{} with events containing two muons and at least one jet of any origin was measured to $\\mathcal{R} = \\unit[4.6 ^{+1.4}_{-1.2} (stat.) \\pm 0.5 (syst.)]{\\%}$. This is found to agree with NLO and LO calculations within known uncertainties.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:26131 |
| Date | 16 July 2012 |
| Creators | Steinbach, Peter |
| Contributors | Kobel, Michael, Husemann, Ulrich, Technische Universität Dresden |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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