{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/236979"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/236979","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"New physics searches in the ZZ sector with the ATLAS experiment","abstract":"This thesis investigates the prospects of measuring anomalous triple gauge boson couplings in the ATLAS detector at the Large Hadron Collider (LHC). The most general (V ZZ, V = Z, g) vertex is parametrised by four couplings, fV = Z,g i=4,5 , all of which are zero in the Standard Model. Non-zero couplings would manifest themselves as an excess of events in ZZ diboson channels, and, if observed, would be a direct probe of new physics beyond the Standard Model. A set of criteria are outlined to select events recorded by ATLAS in two such channels, ZZ to llll(l = e, mu) and ZZ to llnunu. With 1 fb-1 of integrated luminosity at a centre of mass energy of sqrt(s) = 7 TeV, ATLAS can expect to observe 10+/-1 events in the ZZ to llll channel, with 0.5+0.9-0.2 background events. In the ZZ to llnunu channel, 6.2+/-0.7 signal events are expected, with a background of 1.9+2.0-0.2 events. The expected sensitivity of ATLAS to non-zero anomalous couplings is calculated by performing extended, unbinned maximum-likelihood fits to the Z boson transverse momentum spectrum. For 1 fb-1 of integrated luminosity at sqrt(s) = 7 TeV, ATLAS has the potential to place constraints on the coupling parameters of |fZi | < 0.06 and |fig | < 0.07 at the 95% confidence level. These limits assume a form factor with a cutoff of Lambda_FF = 1.2 TeV. As a prelude to ZZ observation, criteria are defined to select Z to ll(l = e, mu) events in the first 315 nb-1 of ATLAS pp collision data at sqrt(s) = 7 TeV. In total 57 events are observed in the electron channel, with 109 in the muon channel, leading to cross section measurements of sigma(Z to ee) = 0.70+/-0.09 (stat)+/-0.10 (syst)+/-0.08 (lumi) pb and sigma(Z to mumu) = 0.90+/-0.09 (stat) +/-0.07 (syst) +/-0.10 (lumi) pb, both of which are consistent with the Standard Model predictions. In addition, this thesis presents a summary of developments made to the Data Acquisition (DAQ) system of the ATLAS Semiconductor Tracker (SCT). These include the construction of a test system, involving a scaled-down version of the entire SCT readout chain. The test system was subsequently used to develop a number of new DAQ features, including a hardware-based event simulator and monitoring framework.","abstract_html":"This thesis investigates the prospects of measuring anomalous triple gauge boson couplings in the ATLAS detector at the Large Hadron Collider (LHC). The most general (V ZZ, V = Z, g) vertex is parametrised by four couplings, fV = Z,g i=4,5 , all of which are zero in the Standard Model. Non-zero couplings would manifest themselves as an excess of events in ZZ diboson channels, and, if observed, would be a direct probe of new physics beyond the Standard Model. A set of criteria are outlined to select events recorded by ATLAS in two such channels, ZZ to llll(l = e, mu) and ZZ to llnunu. With 1 fb-1 of integrated luminosity at a centre of mass energy of sqrt(s) = 7 TeV, ATLAS can expect to observe 10+/-1 events in the ZZ to llll channel, with 0.5+0.9-0.2 background events. In the ZZ to llnunu channel, 6.2+/-0.7 signal events are expected, with a background of 1.9+2.0-0.2 events. The expected sensitivity of ATLAS to non-zero anomalous couplings is calculated by performing extended, unbinned maximum-likelihood fits to the Z boson transverse momentum spectrum. For 1 fb-1 of integrated luminosity at sqrt(s) = 7 TeV, ATLAS has the potential to place constraints on the coupling parameters of |fZi | &lt; 0.06 and |fig | &lt; 0.07 at the 95% confidence level. These limits assume a form factor with a cutoff of Lambda_FF = 1.2 TeV. As a prelude to ZZ observation, criteria are defined to select Z to ll(l = e, mu) events in the first 315 nb-1 of ATLAS pp collision data at sqrt(s) = 7 TeV. In total 57 events are observed in the electron channel, with 109 in the muon channel, leading to cross section measurements of sigma(Z to ee) = 0.70+/-0.09 (stat)+/-0.10 (syst)+/-0.08 (lumi) pb and sigma(Z to mumu) = 0.90+/-0.09 (stat) +/-0.07 (syst) +/-0.10 (lumi) pb, both of which are consistent with the Standard Model predictions. In addition, this thesis presents a summary of developments made to the Data Acquisition (DAQ) system of the ATLAS Semiconductor Tracker (SCT). These include the construction of a test system, involving a scaled-down version of the entire SCT readout chain. The test system was subsequently used to develop a number of new DAQ features, including a hardware-based event simulator and monitoring framework.","abstract_has_math":false,"creators":["Barber, Thomas"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-03-15","date_published":"2011-03-15","updated_at":"2026-07-22T22:24:23Z","subjects":["ATLAS","Anomalous couplings","LHC","Electroweak","Diboson"],"languages":["eng"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/0abac607-9397-4e44-9585-e36afb0599a1/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.16566","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.sponsor","label":"Sponsor","values":["This work was made possible by the Science and Technology Research Council (STFC) under STFC student number PPA/S/S/2006/04325."]},{"key":"dc:creator","label":"Author","values":["Barber, Thomas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2011-03-15"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["http://www.dspace.cam.ac.uk/handle/1810/236979","https://www.repository.cam.ac.uk/handle/1810/236979"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["ATLAS","Anomalous couplings","LHC","Electroweak","Diboson"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/0abac607-9397-4e44-9585-e36afb0599a1/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.16566"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/7592e33f-8236-4432-9061-08f4ce9b2fe1/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis investigates the prospects of measuring anomalous triple gauge boson couplings in the ATLAS detector at the Large Hadron Collider (LHC). 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For 1 fb-1 of integrated luminosity at sqrt(s) = 7 TeV, ATLAS has the potential to place constraints on the coupling parameters of |fZi | < 0.06 and |fig | < 0.07 at the 95% confidence level. These limits assume a form factor with a cutoff of Lambda_FF = 1.2 TeV. As a prelude to ZZ observation, criteria are defined to select Z to ll(l = e, mu) events in the first 315 nb-1 of ATLAS pp collision data at sqrt(s) = 7 TeV. In total 57 events are observed in the electron channel, with 109 in the muon channel, leading to cross section measurements of sigma(Z to ee) = 0.70+/-0.09 (stat)+/-0.10 (syst)+/-0.08 (lumi) pb and sigma(Z to mumu) = 0.90+/-0.09 (stat) +/-0.07 (syst) +/-0.10 (lumi) pb, both of which are consistent with the Standard Model predictions. In addition, this thesis presents a summary of developments made to the Data Acquisition (DAQ) system of the ATLAS Semiconductor Tracker (SCT). These include the construction of a test system, involving a scaled-down version of the entire SCT readout chain. The test system was subsequently used to develop a number of new DAQ features, including a hardware-based event simulator and monitoring framework."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["c3d5595117dffac43b7cfb0bbc155979","0b1a12d4eb169023d6d65183e2d7aac9"]},{"key":"dc:title","label":"Title","values":["New physics searches in the ZZ sector with the ATLAS experiment"]}]}],"canonical_facts":{"dc:contributor.sponsor":["This work was made possible by the Science and Technology Research Council (STFC) under STFC student number PPA/S/S/2006/04325."],"dc:creator":["Barber, Thomas"],"dc:date.issued":["2011-03-15"],"dc:description.abstract":["This thesis investigates the prospects of measuring anomalous triple gauge boson couplings in the ATLAS detector at the Large Hadron Collider (LHC). 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For 1 fb-1 of integrated luminosity at sqrt(s) = 7 TeV, ATLAS has the potential to place constraints on the coupling parameters of |fZi | < 0.06 and |fig | < 0.07 at the 95% confidence level. These limits assume a form factor with a cutoff of Lambda_FF = 1.2 TeV. As a prelude to ZZ observation, criteria are defined to select Z to ll(l = e, mu) events in the first 315 nb-1 of ATLAS pp collision data at sqrt(s) = 7 TeV. In total 57 events are observed in the electron channel, with 109 in the muon channel, leading to cross section measurements of sigma(Z to ee) = 0.70+/-0.09 (stat)+/-0.10 (syst)+/-0.08 (lumi) pb and sigma(Z to mumu) = 0.90+/-0.09 (stat) +/-0.07 (syst) +/-0.10 (lumi) pb, both of which are consistent with the Standard Model predictions. In addition, this thesis presents a summary of developments made to the Data Acquisition (DAQ) system of the ATLAS Semiconductor Tracker (SCT). 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The test system was subsequently used to develop a number of new DAQ features, including a hardware-based event simulator and monitoring framework."],"dc:format.checksum.md5":["c3d5595117dffac43b7cfb0bbc155979","0b1a12d4eb169023d6d65183e2d7aac9"],"dc:identifier.doi":["10.17863/CAM.16566"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/7592e33f-8236-4432-9061-08f4ce9b2fe1/download"],"dc:language":["eng"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["http://www.dspace.cam.ac.uk/handle/1810/236979","https://www.repository.cam.ac.uk/handle/1810/236979"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/0abac607-9397-4e44-9585-e36afb0599a1/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:subject":["ATLAS","Anomalous couplings","LHC","Electroweak","Diboson"],"dc:title":["New physics searches in the ZZ sector with the ATLAS experiment"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:23Z"}