Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This book presents two analyses, the first of which involves the search for a new heavy charged gauge boson, a so-called W¢ boson. This new gauge boson is predicted by some theories extending the Standard Model gauge group to solve some of its conceptual problems. Decays of the W¢ boson in final states with a lepton (ℓ^± = e^±, µ^±) and the corresponding (anti-)neutrino are considered. Data collected by the ATLAS experiment in 2015 at a center of mass energy of sqrt{s}=13 TeV is used for the analysis. In turn, the second analysis presents a measurement of the double-differential cross section of the process pp->Z/gamma^* + X -> l^+l^- + X, including a gamma gamma induced contribution, at a center of mass energy of sqrt{s} = 8 TeV. The measurement is performed in an invariant mass region of 116 GeV to 1500 GeV as a function of invariant mass and absolute rapidity of the l^+l^-- pair, and as a function of invariant mass and pseudorapidity separation of the l^+l^-- pair. The data analyzed was recorded by the ATLAS experiment in 2012 and corresponds to an integrated luminosity of 20.3/fb. It is expected that the measured cross sections are sensitive to the PDFs at very high values of the Bjorken-x scaling variable, and to the photon structure of the proton.

Heavy ions. --- Proton-proton interactions. --- Collisions, Proton --- Interactions, Proton-proton --- Proton interactions --- Proton-proton collisions --- Nuclear reactions --- Ions --- Quantum theory. --- Elementary Particles, Quantum Field Theory. --- Quantum Field Theories, String Theory. --- Quantum dynamics --- Quantum mechanics --- Quantum physics --- Physics --- Mechanics --- Thermodynamics --- Elementary particles (Physics). --- Quantum field theory. --- String theory. --- Models, String --- String theory --- Relativistic quantum field theory --- Field theory (Physics) --- Quantum theory --- Relativity (Physics) --- Elementary particles (Physics) --- High energy physics --- Nuclear particles --- Nucleons --- Nuclear physics

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This thesis addresses, in a novel and elegant way, a combination of measurements that are used to extract so-called double parton scattering. The method is easy to apply and overcomes many of the technical difficulties of older methods. Many new phenomena in particle physics can be observed when particles are collided at the highest energies; one of the highlights in recent years was the discovery of the Higgs boson at the Large Hadron Collider at CERN. Understanding the production mechanism of the Higgs boson at the LHC requires detailed knowledge of the physics of proton-proton collisions. When the density of partons in the protons becomes large, there is a non-negligible probability that more than one parton participates in the interaction and the so-called double parton scattering becomes important. In some cases very particular final state signatures can be observed, which can be regarded as an indication of such double partonic scattering and where the different interactions can be separated. Such multiple partonic interactions play an important role when precise predictions from known processes are required.

Atomic Physics --- Nuclear Physics --- Physics --- Physical Sciences & Mathematics --- Protons --- Proton-proton interactions. --- Partons. --- Scattering --- Measurement. --- Parton model --- Collisions, Proton --- Interactions, Proton-proton --- Proton interactions --- Proton-proton collisions --- Hydrogen nucleus --- Hadrons --- Particles (Nuclear physics) --- Quarks --- Nuclear reactions --- Atoms --- Baryons --- Matter --- Constitution --- Quantum theory. --- Elementary Particles, Quantum Field Theory. --- Measurement Science and Instrumentation. --- Quantum Field Theories, String Theory. --- Elementary particles (Physics). --- Quantum field theory. --- Physical measurements. --- Measurement   . --- String theory. --- Models, String --- String theory --- Measuring --- Mensuration --- Mathematics --- Technology --- Metrology --- Physical measurements --- Measurements, Physical --- Mathematical physics --- Measurement --- Relativistic quantum field theory --- Field theory (Physics) --- Quantum theory --- Relativity (Physics) --- Elementary particles (Physics) --- High energy physics --- Nuclear particles --- Nucleons --- Nuclear physics

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This thesis is based on the first data from the Large Hadron Collider (LHC) at CERN. Its theme can be described as the classical Rutherford scattering experiment adapted to the LHC: measurement of scattering angles to search for new physics and substructure. At the LHC, colliding quarks and gluons exit the proton collisions as collimated particle showers, or jets. The thesis presents studies of the scattering angles of these jets. It includes a phenomenological study at the LHC design energy of 14 TeV, where a model of so-called large extra dimensions is used as a benchmark process for the sensitivity to new physics. The experimental result is the first measurement, made in 2010, by ATLAS, operating at the LHC start-up energy of 7 TeV. The result is compatible with the Standard Model and demonstrates how well the physics and the apparatus are understood. The first data is a tiny fraction of what will be accumulated in the coming years, and this study has set the stage for performing these measurements with confidence as the LHC accumulates luminosity and increases its energy, thereby probing smaller length scales.

Momentum distributions. --- Physics. --- Proton-proton interactions. --- Quantum theory. --- Physics --- Earth & Environmental Sciences --- Physical Sciences & Mathematics --- Nuclear Physics --- Meteorology & Climatology --- Atomic Physics --- Collisions, Proton --- Interactions, Proton-proton --- Proton interactions --- Proton-proton collisions --- Distributions, Momentum --- Cosmology. --- Nuclear physics. --- Elementary particles (Physics). --- Quantum field theory. --- Particle and Nuclear Physics. --- Elementary Particles, Quantum Field Theory. --- Relativistic quantum field theory --- Field theory (Physics) --- Quantum theory --- Relativity (Physics) --- Elementary particles (Physics) --- High energy physics --- Nuclear particles --- Nucleons --- Nuclear physics --- Atomic nuclei --- Atoms, Nuclei of --- Nucleus of the atom --- Astronomy --- Deism --- Metaphysics --- Natural philosophy --- Philosophy, Natural --- Physical sciences --- Dynamics --- Angular momentum --- Nuclear reactions --- Quantum dynamics --- Quantum mechanics --- Quantum physics --- Mechanics --- Thermodynamics

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This thesis introduces readers to the Standard Model, the top quark and its properties, before explaining the concept of spin correlation measurement. The first measurement of top quark spin correlations at the LHC in the lepton+jets decay channel is presented. As the heaviest elementary particle, the top quark plays an essential role in the Standard Model of elementary particle physics. In the case of top quarks being produced in pairs at hadron colliders, the Standard Model predicts their spins to be correlated. The degree of correlation depends on both the production mechanism and properties of the top quark. Any deviation from the Standard Model prediction can be an indicator for new physics phenomena. The thesis employs an advanced top quark reconstruction algorithm including dedicated identification of the up- and down-type quarks from the W boson decay.

Physics. --- Elementary Particles, Quantum Field Theory. --- Quantum Field Theories, String Theory. --- Measurement Science and Instrumentation. --- Quantum theory. --- Physique --- Théorie quantique --- Physics --- Physical Sciences & Mathematics --- Nuclear Physics --- Atomic Physics --- Proton-proton interactions. --- Nuclear spin. --- Particles (Nuclear physics) --- Flavor. --- Spin, Nuclear --- Collisions, Proton --- Interactions, Proton-proton --- Proton interactions --- Proton-proton collisions --- Flavor (Nuclear physics) --- Flavor models (Nuclear physics) --- Top quark models --- Truth models (Nuclear physics) --- Quantum field theory. --- String theory. --- Elementary particles (Physics). --- Physical measurements. --- Measurement. --- Quarks --- Angular momentum (Nuclear physics) --- Nuclear physics --- Nuclear reactions --- Quantum dynamics --- Quantum mechanics --- Quantum physics --- Mechanics --- Thermodynamics --- Measurement   . --- Measuring --- Mensuration --- Mathematics --- Technology --- Metrology --- Physical measurements --- Measurements, Physical --- Mathematical physics --- Measurement --- Models, String --- String theory --- Relativistic quantum field theory --- Field theory (Physics) --- Quantum theory --- Relativity (Physics) --- Elementary particles (Physics) --- High energy physics --- Nuclear particles --- Nucleons