@article{DreinerKraussO'Learyetal.2016,
  author    = {Dreiner, Herbi K. and Krauss, Manuel E. and O'Leary, Ben and Opferkuch, Toby and Staub, Florian},
  title     = {Validity of the CMSSM interpretation of the diphoton excess},
  series = {Physical Review D},
  volume    = {94},
  journal   = {Physical Review D},
  number    = {5},
  doi       = {10.1103/PhysRevD.94.055013},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-187429},
  pages     = {055013},
  year      = {2016},
  abstract  = {It has been proposed that the observed diphoton excess at 750 GeV could be explained within the constrained minimal supersymmetric standard model via resonantly produced stop bound states. We reanalyze this scenario critically and extend previous work to include the constraints from the stability of the electroweak vacuum and from the decays of the stoponium into a pair of Higgs bosons. It is shown that the interesting regions of parameter space with a light stop and Higgs of the desired mass are ruled out by these constraints. This conclusion is not affected by the presence of the bound states because the binding energy is usually very small in the regions of parameter space which can explain the Higgs mass. Thus, this also leads to strong constraints on the diphoton production cross section which is in general too small.},
  language  = {en}
}
@phdthesis{Wagner2008,
  author    = {Wagner, Alexander},
  title     = {Production of Sleptons in e¯e¯-Collisions},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-28307},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {Supersymmetry is currently the best motivated extension of the Standard Model and will be subject to extensive studies in the upcoming generation of colliders. The e-e- mode would be a straight forward extension to the currently planed International Linear Collider, planned to operate in e+e- mode. The low background in this mode may prove advantageous in the study of CP- and Lepton Flavour Violtation. In this work a CP sensitive observable based on transverse beam polarisation is introduced and the impact of neutralino mixing on the total cross section in cas of non-vanishing CP-violtating phases is studied in representative scenarios including non-GUT scenarios. Additionally, the mixing of sleptons is studied in the context of LFV, an analytical approximation is developed, and possible background free measurements of these effects are investigated.},
  subject      = {Supersymmetrie},
  language  = {en}
}
@phdthesis{Karg2007,
  author    = {Karg, Stefan},
  title     = {Calculations of multi-particle processes at the one-loop level: precise predictions for the LHC},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-27505},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2007},
  abstract  = {The Standard Model (SM) of elementary particle physics provides a uniform framework for the description of three fundamental forces, the electromagnetic and weak forces, describing interactions between quarks and leptons, and the strong force, describing a much stronger interaction between the coloured quarks. Numerous experimental tests have been performed in the last thirty years, showing a spectacular agreement with the theoretical predictions of the Standard Model, even at the per mille level, therefore validating the model at the quantum level. An important cornerstone of the Standard Model is the Higgs mechanism, which provides a possible explanation of electroweak symmetry breaking, responsible for the masses of elementary fermions and the W and Z bosons, the carriers of the weak force. This mechanism predicts a scalar boson, the Higgs boson, which has escaped its discovery so far. If the Higgs mechanism is indeed realised in nature, the upcoming Large Hadron Collider (LHC) at CERN will be able to find the associated Higgs boson. The discovery of a Higgs boson by itself is not sufficient to establish the Higgs mechanism, the basic ingredient being the Higgs potential which predicts trilinear and quartic couplings. These have to be confirmed experimentally by the study of multi-Higgs production. We therefore present a calculation of the loop-induced processes gg to HH and gg to HHH, and investigate the observability of multi-Higgs boson production at the LHC in the Standard Model and beyond. While the SM cross sections are too small to allow observation at the LHC, we demonstrate that physics beyond the SM can lead to amplified, observable cross sections. Furthermore, the applicability of the heavy top quark approximation in two- and three-Higgs boson production is investigated. We conclude that multi-Higgs boson production at the SuperLHC is an interesting probe of Higgs sectors beyond the SM and warrants further study. Despite the great success of the SM, it is widely believed that this model cannot be valid for arbitrarily high energies. The LHC will probe the TeV scale and theoretical arguments indicate the appearance of physics beyond the SM at this scale. The search for new physics requires a precise understanding of the SM. Precise theoretical predictions are needed which match the accuracy of the experiments. For the LHC, most analyses require next-to-leading order (NLO) precision. Only then will we be able to reliably verify or falsify different models. At the LHC, many interesting signatures involve more than two particles in the final state. Precise theoretical predictions for such multi-leg processes are a highly nontrivial task and new efficient methods have to be applied. The calculation of the process PP to VV+jet at NLO is an important background process to Higgs production in association with a jet at the LHC. We compute the virtual corrections to this process which form the "bottleneck" for obtaining a complete NLO prediction. The resulting analytic expressions are generated with highly automated computer routines and translated into a flexible Fortran code, which can be employed in the computation of differential cross sections of phenomenological interest. The obtained results for the virtual corrections indicate that the QCD corrections are sizable and should be taken into account in experimental studies for the LHC.},
  subject      = {Higgs-Teilchen},
  language  = {en}
}