Search for dissertations about: "top quark"

Showing result 6 - 10 of 26 swedish dissertations containing the words top quark.

2. 6. Quark Distributions and Charged Higgs Boson Production : Studies of Proton Structure and New Physics

   Author : Johan Alwall; Gunnar Ingelman; Johan Rathsman; Dieter Zeppenfeld; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; quark distributions; parton density functions; proton structure; strange quark; intrinsic charm; charged Higgs boson; supersymmetry; NuTeV; LHC; parton showers; matrix element; elementary particle physics; Fysik; Physics; Fysik;

   Abstract : The Standard Model describes all elementary particles known today, but at larger energies it will have to be complemented with new particles and interactions. To be able to distinguish new physics at proton colliders such as LHC at CERN, it is essential to have an appropriate description of the colliding protons and their interactions. READ MORE

4. 7. Studies of Top Physics Sensitivity and of Pile-Up Effects on Energy Reconstruction in the ATLAS Detector : A Licentiate Thesis About the Treatment of Troublesome $\tau$ and Producing Pulses to Probe Pile-up Problems

   Author : Simon Molander; Sten Hellman; Jörgen Sjölin; Klas Hultqvist; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; tau; top quark; ATLAS; LHC; TILE calorimeter; sensitivity; cross-section; standard model; physics; optimal filtering; energy reconstruction; hadronic tau decay; fysik; Physics;

   Abstract : This thesis presents two studies conducted using the ATLAS detectorat the Large Hadron Collider. The first one is a technical study abouthow out-of-time pile-up affects energy reconstruction using the optimalfiltering 2 algorithm in the TILE calorimeter sub detector. The studyis conducted using a pulse simulator software that is also described. READ MORE

5. 8. First determination of the electric charge of the top quark

   Author : Per Hansson; Bengt Lund-Jensen; Peter Hansen; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

   Abstract : In this thesis, the first determination of the electric charge of the top quark is presented using 370pb-1 of data recorded by the DØ detector at the Fermilab Tevatron accelerator. ttbar events are selected with one isolated electron or muon and at least four jets out of which two are b-tagged by reconstruction of a secondary decay vertex (SVT). READ MORE

6. 9. Measurements of the Top Quark Pair Production Cross Section and an Estimate of the DØ Silicon Detector Lifetime

   Author : Sara Strandberg; Christophe Clément; Barbro Åsman; Steinar Stapnes; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; particle physics; top quark pair production cross section; silicon radiation damage; DØ detector; Tevatron accelerator; Elementary particle physics; Elementarpartikelfysik; Physics; fysik;

   Abstract : This thesis presents two measurements of the top quark pair production cross section at sqrt{s} = 1.96 TeV using data from the DØ experiment. Both measurements are performed in the dilepton final state and make use of secondary vertex b-tagging. READ MORE

7. 10. Constraining the top-Z coupling using the (ttWj)EW process with the ATLAS experiment : A search for physics beyond the Standard Model

   Author : Nabila Ahlgren; Jörgen Sjölin; Robert Schöfbeck; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; particle physics; ATLAS; top physics; fysik; Physics;

   Abstract : The Standard Model (SM) of particle physics, having been confirmed by numerous experiments, is one of the most successful theories in physics. It describes all known elementary particles and their interactions through the electromagnetic, strong and weak force. READ MORE