Top-quark pair production in association with a Z boson in the final state with four charged leptons
Top-quark pair production in association with a Z boson in the final state with four charged leptons
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DissertationDate of Exam
09.09.2019Date of Publication
29.10.2019Advisor
Cristinziani, MarkusCo-Referee
Dingfelder, Jochen ChristianMetadata
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Abstract
The production cross section of a top-quark pair in association with a Z boson is measured in the channel with four reconstructed leptons, using 36.1 fb-1 of proton–proton collisions, collected with the ATLAS detector at the Large Hadron Collider at CERN. A profile likelihood fit is performed, using four signal regions and a control region for the ZZ background. A total of 48 events are observed in the signal regions and a ttZ cross section of σttZ = 1.07+0.28-0.25 (stat.)+0.10-0.09 (syst.)pb is extracted, which is compatible with the Standard Model calculation. Combined with other channels, the measured cross section is σttZ = 0.95 ± 0.08 , (stat.) ± 0.10 (syst.)pb. Data is unfolded in the 4l channel, to compute the differential cross section for pT(Z(ll)) and ΔΦZ(ll), variables sensitive to EFT operators, that modify the ttZ vertex.
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530 PhysikPart of Series
BONN-IR ; 2019-07Heer, Sebastian: Top-quark pair production in association with a Z boson in the final state with four charged leptons. - Bonn, 2019. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-56378
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-56378
@phdthesis{handle:20.500.11811/8102,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-56378,
author = {{Sebastian Heer}},
title = {Top-quark pair production in association with a Z boson in the final state with four charged leptons},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2019,
month = oct,
volume = 2019-07,
note = {The production cross section of a top-quark pair in association with a Z boson is measured in the channel with four reconstructed leptons, using 36.1 fb-1 of proton–proton collisions, collected with the ATLAS detector at the Large Hadron Collider at CERN. A profile likelihood fit is performed, using four signal regions and a control region for the ZZ background. A total of 48 events are observed in the signal regions and a ttZ cross section of σttZ = 1.07+0.28-0.25 (stat.)+0.10-0.09 (syst.)pb is extracted, which is compatible with the Standard Model calculation. Combined with other channels, the measured cross section is σttZ = 0.95 ± 0.08 , (stat.) ± 0.10 (syst.)pb. Data is unfolded in the 4l channel, to compute the differential cross section for pT(Z(ll)) and ΔΦZ(ll), variables sensitive to EFT operators, that modify the ttZ vertex.},
url = {https://hdl.handle.net/20.500.11811/8102}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-56378,
author = {{Sebastian Heer}},
title = {Top-quark pair production in association with a Z boson in the final state with four charged leptons},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2019,
month = oct,
volume = 2019-07,
note = {The production cross section of a top-quark pair in association with a Z boson is measured in the channel with four reconstructed leptons, using 36.1 fb-1 of proton–proton collisions, collected with the ATLAS detector at the Large Hadron Collider at CERN. A profile likelihood fit is performed, using four signal regions and a control region for the ZZ background. A total of 48 events are observed in the signal regions and a ttZ cross section of σttZ = 1.07+0.28-0.25 (stat.)+0.10-0.09 (syst.)pb is extracted, which is compatible with the Standard Model calculation. Combined with other channels, the measured cross section is σttZ = 0.95 ± 0.08 , (stat.) ± 0.10 (syst.)pb. Data is unfolded in the 4l channel, to compute the differential cross section for pT(Z(ll)) and ΔΦZ(ll), variables sensitive to EFT operators, that modify the ttZ vertex.},
url = {https://hdl.handle.net/20.500.11811/8102}
}
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