Search for charged lepton-flavour violation in top-quark decays at the LHC with the ATLAS detector
Search for charged lepton-flavour violation in top-quark decays at the LHC with the ATLAS detector
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DissertationDate of Exam
26.04.2019Date of Publication
06.09.2019Advisor
Cristinziani, MarkusCo-Referee
Brock, Ian C.Metadata
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Abstract
A direct search for charged lepton-flavour violation in top-quark decays is presented. The data analysed correspond to 79.8 fb-1 of proton-proton collisions at a centre-of-mass energy of √s = 13 TeV delivered by the LHC and recorded by the ATLAS experiment. The process studied is the production of top-quark pairs, where one top quark decays into a pair of opposite-sign different-flavour charged leptons and an up-type quark, while the other decays semileptonically according to the Standard Model. The signature of the signal is thus characterised by the presence of three charged leptons, a light jet and a b-jet. A multivariate discriminant is deployed and its distribution used as input to extract the signal strength. In the absence of a signal, an upper limit on the branching ratio of B (t → ll'q) < 1.86 x 10-5 is set at the 95% confidence level.
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530 PhysikGottardo, Carlo Alberto: Search for charged lepton-flavour violation in top-quark decays at the LHC with the ATLAS detector. - Bonn, 2019. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-54736
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-54736
@phdthesis{handle:20.500.11811/7932,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-54736,
author = {{Carlo Alberto Gottardo}},
title = {Search for charged lepton-flavour violation in top-quark decays at the LHC with the ATLAS detector},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2019,
month = sep,
note = {A direct search for charged lepton-flavour violation in top-quark decays is presented. The data analysed correspond to 79.8 fb-1 of proton-proton collisions at a centre-of-mass energy of √s = 13 TeV delivered by the LHC and recorded by the ATLAS experiment. The process studied is the production of top-quark pairs, where one top quark decays into a pair of opposite-sign different-flavour charged leptons and an up-type quark, while the other decays semileptonically according to the Standard Model. The signature of the signal is thus characterised by the presence of three charged leptons, a light jet and a b-jet. A multivariate discriminant is deployed and its distribution used as input to extract the signal strength. In the absence of a signal, an upper limit on the branching ratio of B (t → ll'q) < 1.86 x 10-5 is set at the 95% confidence level.},
url = {https://hdl.handle.net/20.500.11811/7932}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-54736,
author = {{Carlo Alberto Gottardo}},
title = {Search for charged lepton-flavour violation in top-quark decays at the LHC with the ATLAS detector},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2019,
month = sep,
note = {A direct search for charged lepton-flavour violation in top-quark decays is presented. The data analysed correspond to 79.8 fb-1 of proton-proton collisions at a centre-of-mass energy of √s = 13 TeV delivered by the LHC and recorded by the ATLAS experiment. The process studied is the production of top-quark pairs, where one top quark decays into a pair of opposite-sign different-flavour charged leptons and an up-type quark, while the other decays semileptonically according to the Standard Model. The signature of the signal is thus characterised by the presence of three charged leptons, a light jet and a b-jet. A multivariate discriminant is deployed and its distribution used as input to extract the signal strength. In the absence of a signal, an upper limit on the branching ratio of B (t → ll'q) < 1.86 x 10-5 is set at the 95% confidence level.},
url = {https://hdl.handle.net/20.500.11811/7932}
}
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