@phdthesis{Pasold2016,
  author    = {Pasold, Christian},
  title     = {QCD and electroweak NLO corrections to W + Photon and Z + Photon production including leptonic decays},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137456},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {At a hadron collider as the LHC or the Tevatron the production of a photon in association with a leptonically decaying vector boson represents an important class of processes. These processes stand out due to a very clean signal of a photon and two leptons. Furthermore they provide direct access to the photon-vector-boson couplings and thus an easy opportunity to test the gauge sector of the Standard Model. Within the scope of this work we present a full calculation of the next-to-leading-order corrections which include the O (αs) corrections of the strong interaction as well as the electroweak corrections of O (α) including all photon-induced contributions. For the creation of matrix elements we use methods based on Feynman diagrams. The IR singularities are treated with the dipole subtraction technique. In order to separate photons from jets, a quark-to-photon fragmentation function ´a la Glover / Morgan or Frixione's cone isolation is employed. Moreover, two different scenarios for charged leptons in the fi state were considered. The fi scenario for dressed leptons assumes that a charged lepton and a photon will be recombined if they are collinear. In the second scenario for bare muons it is assumed that leptons and photon can be separated in a detector also if they are collinear. For our calculation we implemented all corrections into a fl Monte Carlo program. Be- sides the computation of the total cross section this program is also able to generate diff tial distributions of several experimentally motivated observables. Apart from the expected large electroweak corrections in the high transverse-momentum regions and sizeable corrections in the resonance regions of the transverse or the invariant masses we found photon-induced corrections up to several 10\% for high transverse momenta. Within run I at the LHC for 7/8 TeV the experimental accuracy for Vγ production was roughly 10\%. Due to the higher luminosity at run II this accuracy will be reduced to the level of a few percent so that corrections of the same order within the theoretical predictions might become relevant. In this work we present results for the total cross section at the LHC for 7, 8 and 14 TeV and the corresponding distributions for 14 TeV.},
  subject      = {Quantenchromodynamik},
  language  = {en}
}
@phdthesis{Bach2013,
  author    = {Bach, Fabian},
  title     = {Charged Current Top Quark Couplings at the LHC},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82358},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {The top quark plays an important role in current particle physics, from a theoretical point of view because of its uniquely large mass, but also experimentally because of the large number of top events recorded by the LHC experiments ATLAS and CMS, which makes it possible to directly measure the properties of this particle, for example its couplings to the other particles of the standard model (SM), with previously unknown precision. In this thesis, an effective field theory approach is employed to introduce a minimal and consistent parametrization of all anomalous top couplings to the SM gauge bosons and fermions which are compatible with the SM symmetries. In addition, several aspects and consequences of the underlying effective operator relations for these couplings are discussed. The resulting set of couplings has been implemented in the parton level Monte Carlo event generator WHIZARD in order to provide a tool for the quantitative assessment of the phenomenological implications at present and future colliders such as the LHC or a planned international linear collider. The phenomenological part of this thesis is focused on the charged current couplings of the top quark, namely anomalous contributions to the trilinear tbW coupling as well as quartic four-fermion contact interactions of the form tbff, both affecting single top production as well as top decays at the LHC. The study includes various aspects of inclusive cross section measurements as well as differential distributions of single tops produced in the t channel, bq → tq', and in the s channel, ud → tb. We discuss the parton level modelling of these processes as well as detector effects, and finally present the prospected LHC reach for setting limits on these couplings with 10 resp. 100 fb-1 of data recorded at √s = 14 TeV.},
  subject      = {LHC},
  language  = {en}
}
@phdthesis{Mueck2004,
  author    = {M{\"u}ck, Alexander},
  title     = {The standard model in 5D : theoretical consistency and experimental constraints},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-10591},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2004},
  abstract  = {The four-dimensional Minkowski space is known to be a good description for space-time down to the length scales probed by the latest high-energy experiments. Nevertheless, there is the viable and exciting possibility that additional space-time structure will be observable in the next generation of collider experiments. Hence, we discuss different extensions of the standard model of particle physics with an extra dimension at the TeV-scale. We assume that some of the gauge and Higgs bosons propagate in one additional spatial dimension, while matter fields are confined to a four-dimensional subspace, the usual Minkowski space. After compactification on an S^1/Z_2 orbifold, an effective four-dimensional theory is obtained where towers of Kaluza-Klein (KK) modes, in addition to the standard model fields, reflect the higher-dimensional structure of space-time. The models are elaborated from the 5D Lagrangian to the Feynman rules of the KK modes. Special attention is paid to an appropriate generalization of the Rxi-gauge and the interplay between spontaneous symmetry breaking and compactification. Confronting the observables in 5D standard model extensions with combined precision measurements at the Z-boson pole and the latest data from LEP2, we constrain the possible size R of the extra dimension experimentally. A multi-parameter fit of all relevant input parameters leads to bounds for the compactification scale M=1/R in the range 4-6 TeV at the 2 sigma confidence level and shows how the mass of the Higgs boson is correlated with the size of an extra dimension. Considering a future linear e+e- collider, we outline the discovery potential for an extra dimension using the proposed TESLA specifications as an example. As a consistency check for the various models, we analyze Ward identities and the gauge boson equivalence theorem in W-pair production and find that gauge symmetry is preserved by a complex interplay of the Kaluza-Klein modes. In this context, we point out the close analogy between the traditional Higgs mechanism and mass generation for gauge bosons via compactification. Beyond the tree-level, the higher-dimensional models studied extensively in the literature and in the first part of this thesis have to be extended. We modify the models by the inclusion of brane kinetic terms which are required as counter terms. Again, we derive the corresponding 4D theory for the KK towers paying special attention to gauge fixing and spontaneous symmetry breaking. Finally, the phenomenological implications of the new brane kinetic terms are investigated in detail.},
  subject      = {Standardmodell <Elementarteilchenphysik>},
  language  = {en}
}