Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature
This thesis presents a search for the diffuse astrophysical neutrino flux in 335 days of IceCube data. IceCube is a 1 km$^{3}$ neutrino detector located at the South Pole, consisting of 86 strings, each equipped with 60 Digital Optical Photomultipliers (DOMs), frozen in the ice. The detector was sti...
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Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät
2015
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ftdesyvdb:oai:bib-pubdb1.desy.de:393645 2023-05-15T18:23:21+02:00 Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature Schönwald, Arne Kolanoski, Hermann Kowalski, Marek Böser, Sebastian DE 2015 https://bib-pubdb1.desy.de/record/393645 https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2017-11588%22 eng eng Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät info:eu-repo/semantics/altIdentifier/doi/10.3204/PUBDB-2017-11588 info:eu-repo/semantics/altIdentifier/doi/10.18452/17514 https://bib-pubdb1.desy.de/record/393645 https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2017-11588%22 info:eu-repo/semantics/openAccess Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät 140 pp. (2015). doi:10.18452/17514 = Humboldt Universität, Dissertation, 2015 info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion 2015 ftdesyvdb https://doi.org/10.18452/17514 https://doi.org/10.3204/PUBDB-2017-11588 2022-06-30T20:17:12Z This thesis presents a search for the diffuse astrophysical neutrino flux in 335 days of IceCube data. IceCube is a 1 km$^{3}$ neutrino detector located at the South Pole, consisting of 86 strings, each equipped with 60 Digital Optical Photomultipliers (DOMs), frozen in the ice. The detector was still in construction when the data used in this analysis was taken, therefore only 59 strings were available (IC59).The analysis presented here is sensitive to all three neutrino flavors. Neutrinos interacting with nuclei in the ice produce charged particles which emit Cherenkov light. This light is recorded by the DOMs and used for the event reconstruction. These neutrino events must be extracted from the huge background of atmospheric muons, which is $10^{8}$ times more common than neutrino events at trigger level. Finally, atmospheric and astrophysical neutrinos need to be distinguished statistically, based on the reconstructed neutrino energies.To obtain a robust prediction of atmospheric muon events at the final level of the event selection, a huge simulation sample of atmospheric muons has been produced. This analysis was the first to achieve a livetime of more than one year of simulated atmospheric muon events with $E \geq 10$ TeV.A first analysis counting the number of events with an energy $E>38$ TeV found 8 events with energies between 39 TeV and 67 TeV for a background prediction of $3.6\pm 0.3$ events. This excess was further investigated with a maximum likelihood fit with an energy threshold of 10 TeV. No astrophysical neutrino flux was required to describe the excess in the data. Instead, it was absorbed by a higher normalization of the atmospheric neutrino flux. If no constraints from independent measurements or models of the atmospheric neutrino flux are applied, a 90 % upper limit on the all-flavor astrophysical neutrino flux of $E^{2}\Phi_{astro,\;ul}=1.7\cdot 10^{-8} {\rm GeV}{\rm s}^{-1}{\rm sr}^{-1}{\rm cm}^{-2}$ in the energy range of $20\;{\rm TeV} \leq E \leq 3.0\;{\rm PeV}$ can be derived. ... Doctoral or Postdoctoral Thesis South pole DESY Publication Database (PUBDB) South Pole |
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Open Polar |
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DESY Publication Database (PUBDB) |
op_collection_id |
ftdesyvdb |
language |
English |
description |
This thesis presents a search for the diffuse astrophysical neutrino flux in 335 days of IceCube data. IceCube is a 1 km$^{3}$ neutrino detector located at the South Pole, consisting of 86 strings, each equipped with 60 Digital Optical Photomultipliers (DOMs), frozen in the ice. The detector was still in construction when the data used in this analysis was taken, therefore only 59 strings were available (IC59).The analysis presented here is sensitive to all three neutrino flavors. Neutrinos interacting with nuclei in the ice produce charged particles which emit Cherenkov light. This light is recorded by the DOMs and used for the event reconstruction. These neutrino events must be extracted from the huge background of atmospheric muons, which is $10^{8}$ times more common than neutrino events at trigger level. Finally, atmospheric and astrophysical neutrinos need to be distinguished statistically, based on the reconstructed neutrino energies.To obtain a robust prediction of atmospheric muon events at the final level of the event selection, a huge simulation sample of atmospheric muons has been produced. This analysis was the first to achieve a livetime of more than one year of simulated atmospheric muon events with $E \geq 10$ TeV.A first analysis counting the number of events with an energy $E>38$ TeV found 8 events with energies between 39 TeV and 67 TeV for a background prediction of $3.6\pm 0.3$ events. This excess was further investigated with a maximum likelihood fit with an energy threshold of 10 TeV. No astrophysical neutrino flux was required to describe the excess in the data. Instead, it was absorbed by a higher normalization of the atmospheric neutrino flux. If no constraints from independent measurements or models of the atmospheric neutrino flux are applied, a 90 % upper limit on the all-flavor astrophysical neutrino flux of $E^{2}\Phi_{astro,\;ul}=1.7\cdot 10^{-8} {\rm GeV}{\rm s}^{-1}{\rm sr}^{-1}{\rm cm}^{-2}$ in the energy range of $20\;{\rm TeV} \leq E \leq 3.0\;{\rm PeV}$ can be derived. ... |
author2 |
Kolanoski, Hermann Kowalski, Marek Böser, Sebastian |
format |
Doctoral or Postdoctoral Thesis |
author |
Schönwald, Arne |
spellingShingle |
Schönwald, Arne Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature |
author_facet |
Schönwald, Arne |
author_sort |
Schönwald, Arne |
title |
Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature |
title_short |
Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature |
title_full |
Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature |
title_fullStr |
Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature |
title_full_unstemmed |
Investigation of all-flavour neutrino fluxes with the IceCube detector using the cascade signature |
title_sort |
investigation of all-flavour neutrino fluxes with the icecube detector using the cascade signature |
publisher |
Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät |
publishDate |
2015 |
url |
https://bib-pubdb1.desy.de/record/393645 https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2017-11588%22 |
op_coverage |
DE |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät 140 pp. (2015). doi:10.18452/17514 = Humboldt Universität, Dissertation, 2015 |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3204/PUBDB-2017-11588 info:eu-repo/semantics/altIdentifier/doi/10.18452/17514 https://bib-pubdb1.desy.de/record/393645 https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2017-11588%22 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.18452/17514 https://doi.org/10.3204/PUBDB-2017-11588 |
_version_ |
1766202924401164288 |