{"id":{"repo_id":"uic","oai_identifier":"oai:figshare.com:article/32995328"},"canonical_url":"https://search.dev.ndltd.org/etd/uic/oai:figshare.com:article/32995328","repository":{"repo_id":"uic","name":"University of Illinois - Chicago","base_url":"https://api.figshare.com/v2/oai"},"display":{"title":"Improved Search for Heavy Neutral Scalars A and H Using ttZ Events from 13 TeV pp Collisions at CMS","abstract":"This thesis presents a search for heavy neutral scalars A and H via the cascade decay A->ZH with H->tt and semileptonic decays of the top quarks. The search is performed using proton-proton collision data recorded by the CMS experiment at sqrt(s) = 13 TeV during LHC Run 2, corresponding to an integrated luminosity of 138 fb^-1. The analysis targets events with three charged leptons, missing transverse momentum, and four or more jets, at least one of which is b-tagged. From these, a Z boson candidate and two top quark candidates are reconstructed, allowing reconstruction of the heavy resonances. No evidence for a signal is observed. Model-independent upper limits on the product of cross section and branching fraction are set for A masses from 430 to 2100 GeV and H masses from 330 to 2000 GeV, assuming narrow resonances. The results are used to constrain the parameter space of the type-II two-Higgs-doublet model, excluding regions relevant to electroweak baryogenesis. A statistical combination is performed with a complementary CMS search in the two-lepton final state, where the top quark pair decays entirely to hadrons. The combination improves the expected sensitivity and extends the excluded regions.","abstract_html":"This thesis presents a search for heavy neutral scalars A and H via the cascade decay A->ZH with H->tt and semileptonic decays of the top quarks. The search is performed using proton-proton collision data recorded by the CMS experiment at sqrt(s) = 13 TeV during LHC Run 2, corresponding to an integrated luminosity of 138 fb^-1. The analysis targets events with three charged leptons, missing transverse momentum, and four or more jets, at least one of which is b-tagged. From these, a Z boson candidate and two top quark candidates are reconstructed, allowing reconstruction of the heavy resonances. No evidence for a signal is observed. Model-independent upper limits on the product of cross section and branching fraction are set for A masses from 430 to 2100 GeV and H masses from 330 to 2000 GeV, assuming narrow resonances. The results are used to constrain the parameter space of the type-II two-Higgs-doublet model, excluding regions relevant to electroweak baryogenesis. A statistical combination is performed with a complementary CMS search in the two-lepton final state, where the top quark pair decays entirely to hadrons. The combination improves the expected sensitivity and extends the excluded regions.","abstract_has_math":false,"creators":["Michelle Hawksworth (24400280)"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026-05-01T00:00:00Z","date_published":"2026-05-01T00:00:00Z","updated_at":"2026-07-27T21:33:54Z","subjects":["Physics","Elementary Particles and High Energy"],"languages":[],"rights":["In Copyright","Open Access after 2028-05-01"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.25417/uic.32995328.v1","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Michelle Hawksworth (24400280)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2026-05-01T00:00:00Z"]},{"key":"dc:relation","label":"Dc Relation","values":["https://figshare.com/articles/thesis/Improved_Search_for_Heavy_Neutral_Scalars_A_and_H_Using_ttZ_Events_from_13_TeV_pp_Collisions_at_CMS/32995328"]},{"key":"dc:type","label":"Dc Type","values":["Text","Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics","Elementary Particles and High Energy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright","Open Access after 2028-05-01"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.25417/uic.32995328.v1"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis presents a search for heavy neutral scalars A and H via the cascade decay A->ZH with H->tt and semileptonic decays of the top quarks. The search is performed using proton-proton collision data recorded by the CMS experiment at sqrt(s) = 13 TeV during LHC Run 2, corresponding to an integrated luminosity of 138 fb^-1. The analysis targets events with three charged leptons, missing transverse momentum, and four or more jets, at least one of which is b-tagged. From these, a Z boson candidate and two top quark candidates are reconstructed, allowing reconstruction of the heavy resonances. No evidence for a signal is observed. Model-independent upper limits on the product of cross section and branching fraction are set for A masses from 430 to 2100 GeV and H masses from 330 to 2000 GeV, assuming narrow resonances. The results are used to constrain the parameter space of the type-II two-Higgs-doublet model, excluding regions relevant to electroweak baryogenesis. A statistical combination is performed with a complementary CMS search in the two-lepton final state, where the top quark pair decays entirely to hadrons. The combination improves the expected sensitivity and extends the excluded regions."]},{"key":"dc:title","label":"Title","values":["Improved Search for Heavy Neutral Scalars A and H Using ttZ Events from 13 TeV pp Collisions at CMS"]}]}],"canonical_facts":{"dc:creator":["Michelle Hawksworth (24400280)"],"dc:date":["2026-05-01T00:00:00Z"],"dc:description":["This thesis presents a search for heavy neutral scalars A and H via the cascade decay A->ZH with H->tt and semileptonic decays of the top quarks. The search is performed using proton-proton collision data recorded by the CMS experiment at sqrt(s) = 13 TeV during LHC Run 2, corresponding to an integrated luminosity of 138 fb^-1. The analysis targets events with three charged leptons, missing transverse momentum, and four or more jets, at least one of which is b-tagged. From these, a Z boson candidate and two top quark candidates are reconstructed, allowing reconstruction of the heavy resonances. No evidence for a signal is observed. Model-independent upper limits on the product of cross section and branching fraction are set for A masses from 430 to 2100 GeV and H masses from 330 to 2000 GeV, assuming narrow resonances. The results are used to constrain the parameter space of the type-II two-Higgs-doublet model, excluding regions relevant to electroweak baryogenesis. A statistical combination is performed with a complementary CMS search in the two-lepton final state, where the top quark pair decays entirely to hadrons. The combination improves the expected sensitivity and extends the excluded regions."],"dc:identifier":["10.25417/uic.32995328.v1"],"dc:relation":["https://figshare.com/articles/thesis/Improved_Search_for_Heavy_Neutral_Scalars_A_and_H_Using_ttZ_Events_from_13_TeV_pp_Collisions_at_CMS/32995328"],"dc:rights":["In Copyright","Open Access after 2028-05-01"],"dc:subject":["Physics","Elementary Particles and High Energy"],"dc:title":["Improved Search for Heavy Neutral Scalars A and H Using ttZ Events from 13 TeV pp Collisions at CMS"],"dc:type":["Text","Thesis"]},"updated_at":"2026-07-27T21:33:54Z"}