% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Lorenz:316167,
      author       = {Lorenz, Sebastian},
      othercontributors = {Hagner, Caren and Wurm, Michael and Wonsak, Bjoern Soenke},
      title        = {{T}opological {T}rack {R}econstruction in {L}iquid
                      {S}cintillator and {LENA} as a {F}ar-{D}etector in an {LBNO}
                      {E}xperiment},
      issn         = {1435-8085},
      school       = {Universität Hamburg},
      type         = {Dissertation},
      address      = {Hamburg},
      publisher    = {Verlag Deutsches Elektronen-Synchrotron},
      reportid     = {PUBDB-2016-06366, DESY-THESIS-2016-037},
      series       = {DESY-THESIS},
      pages        = {230},
      year         = {2016},
      note         = {Dissertation, Universität Hamburg, 2016},
      abstract     = {Unsegmented liquid scintillator (LSc) neutrino detectors
                      have proven to be successful instruments of neutrino
                      physics. They usually measure terrestrial and astrophysical
                      low-energy (LE) neutrinos and antineutrinos with energies up
                      to some tens of MeV. Designs for next-generation detectors
                      based on this technology intend to use several tens of
                      kilotons of LSc. Two examples are the Low Energy Neutrino
                      Astronomy (LENA) project with 50 kt considered in Europe and
                      the Jiangmen Underground Neutrino Observatory (JUNO) with 20
                      kt already under construction in China. A key factor to
                      reach the scientific goals of these projects, e.g., the
                      determination of the neutrino mass ordering (MO) in the case
                      of JUNO, will be the efficient rejection of background from
                      radioisotopes produced by cosmogenic muons. This requires
                      accurate reconstructions of extended muon event topologies
                      in the LSc volume.The first part of this work is about the
                      implementation of a novel, iterative track reconstruction
                      procedure for unsegmented LSc detectors and a basic
                      evaluation of its performance with the LENA detector
                      simulation. The ultimate goal of the new method is to
                      reconstruct the spatial number density distribution of
                      optical photon emissions. This will give access to a charged
                      particle's differential energy loss dE / dx in LSc and
                      resolve details of an event's topology, e.g., induced
                      particle showers. Visual comparisons of reconstruction
                      outcomes with Monte Carlo (MC) truths already provide
                      evidence for this capability. First quantitative results
                      were extracted from the 3D reconstruction data of
                      fully-contained muons in the kinetic energy range from 1 to
                      10 GeV: Despite some well understood systematic effects in
                      the current method to find start and end point of a track,
                      resolutions ≲ 25 cm lateral to the reconstructed track
                      were ascertained for these spots. The determined angular
                      resolution of ∼1.4° at 1 GeV improves to ∼0.3° with
                      rising muon energy. With the current analysis method, the
                      relative energy resolution approximately follows $10\%$ /
                      Sqrt(E / 1 GeV) + $2\%.The$ application of the new technique
                      is not the limited to cosmogenic muons. Future advancements
                      may allow the reconstruction of the complex event topologies
                      of GeV neutrino interactions. Beyond the (usual) LE neutrino
                      program, this case would open up a new range of applications
                      for unsegmented LSc detectors. The second part of this work
                      therefore investigates the performance of LENA in a
                      long-baseline neutrino oscillation (LBNO) experiment with a
                      conventional multi-GeV neutrino beam as proposed in the
                      Large Apparatus for Grand Unification and Neutrino
                      Astrophysics (LAGUNA)-LBNO design study: A 750 kW neutrino
                      beam aiming over a distance of ∼2300 km from the Conseil
                      Européen pour laRecherche Nucléaire (CERN) to the
                      Pyhäsalmi mine in central Finland. The potential to
                      discover the neutrino MO and leptonic CP-violation was
                      studied with the General Long Baseline Experiment Simulator
                      (GLoBES) package in combination with MC techniques. Assuming
                      ten years of runtime equally shared between neutrino and
                      antineutrino mode, only a low sensitivity to CP-violation
                      was found. However, in the MO study, the inverted ordering
                      (IO) (normal ordering (NO)) hypothesis could be rejected at
                      true NO (IO) with a median sensitivity of 4.6-6.7σ
                      (4.2-5.8σ), depending on the true value of the CP-violating
                      phase $δ_CP$ .},
      cin          = {UNI/EXP},
      cid          = {$I:(DE-H253)UNI_EXP-20120731$},
      pnm          = {899 - ohne Topic (POF3-899)},
      pid          = {G:(DE-HGF)POF3-899},
      experiment   = {EXP:(DE-MLZ)NOSPEC-20140101},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)29 / PUB:(DE-HGF)11},
      doi          = {10.3204/PUBDB-2016-06366},
      url          = {https://bib-pubdb1.desy.de/record/316167},
}