Search for pair production of up-type vector-like quarks and for four-top-quark events in final states with multiple b-jets with the ATLAS detector

dc.WoS.categoriesPhysics, Particles & Fieldsen_US
dc.authorid0000-0001-5050-8441en_US
dc.contributor.authorÇetin, Serkant Ali
dc.date.accessioned2020-06-24T08:38:53Z
dc.date.available2020-06-24T08:38:53Z
dc.date.issued2018-07-12
dc.departmentFakülteler, Mühendislik ve Doğa Bilimleri Fakültesi, Enerji Sistemleri Mühendisliği Bölümüen_US
dc.description.abstractA search for pair production of up-type vector-like quarks (T) with a significant branching ratio into a top quark and either a Standard Model Higgs boson or a Z boson is presented. The same analysis is also used to search for four-top-quark production in several new physics scenarios. The search is based on a dataset of pp collisions at root s = 13TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider and corresponds to an integrated luminosity of 36.1 fb(-1). Data are analysed in the lepton+jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets, as well as the jets+E-T(miss) final state, characterised by multiple jets and large missing transverse momentum. The search exploits the high multiplicity of jets identified as originating from b-quarks, and the presence of boosted, hadronically decaying top quarks and Higgs bosons reconstructed as large-radius jets, characteristic of signal events. No significant excess above the Standard Model expectation is observed, and 95% CL upper limits are set on the production cross sections for the different signal processes considered. These cross-section limits are used to derive lower limits on the mass of a vector-like T quark under several branching ratio hypotheses assuming contributions from T -> Wb, Zt, Ht decays. The 95% CL observed lower limits on the T quark mass range between 0.99TeV and 1.43TeV for all possible values of the branching ratios into the three decay modes considered, significantly extending the reach beyond that of previous searches. Additionally, upper limits on anomalous four-top-quark production are set in the context of an effective field theory model, as well as in an universal extra dimensions model.en_US
dc.fullTextLevelFull Texten_US
dc.identifier.doi10.1007/JHEP07(2018)089en_US
dc.identifier.issn1029-8479
dc.identifier.scopus2-s2.0-85050096235en_US
dc.identifier.urihttps://hdl.handle.net/11411/2274
dc.identifier.urihttps://doi.org/10.1007/JHEP07(2018)089
dc.identifier.wosWOS:000438622000007en_US
dc.identifier.wosqualityQ1en_US
dc.indekslendigikaynakWeb of Scienceen_US
dc.indekslendigikaynakScopusen_US
dc.issue7en_US
dc.language.isoenen_US
dc.nationalInternationalen_US
dc.numberofauthors500+en_US
dc.publisherSPRINGERen_US
dc.relation.ispartofJOURNAL OF HIGH ENERGY PHYSICSen_US
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanıen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectBeyond Standard Modelen_US
dc.subjectHadron-Hadron scattering (experiments)en_US
dc.subjectvector-like quarksen_US
dc.titleSearch for pair production of up-type vector-like quarks and for four-top-quark events in final states with multiple b-jets with the ATLAS detectoren_US
dc.typeArticleen_US

Dosyalar

Orijinal paket
Listeleniyor 1 - 1 / 1
Yükleniyor...
Küçük Resim
İsim:
2018WoSÇetin76.pdf
Boyut:
1.42 MB
Biçim:
Adobe Portable Document Format
Açıklama:
Lisans paketi
Listeleniyor 1 - 1 / 1
Küçük Resim Yok
İsim:
license.txt
Boyut:
1.71 KB
Biçim:
Item-specific license agreed upon to submission
Açıklama: