Artículo
A search for ttbar resonances in the lepton plus jets final state with ATLAS using 4.7 fb-1 of pp collisions at √s = 7 TeV
Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Alonso, Francisco
; Anduaga, Xabier Sebastian
; Dova, Maria Teresa
; González Silva, María Laura
; Monticelli, Fernando Gabriel
; Otero y Garzon, Gustavo Javier
; Piegaia, Ricardo Nestor
; Romeo, Gaston Leonardo
; Tripiana, Martin Fernando
; Zhuang, X.; Zhuravlov, V.; Zieminska, D.; Zimin, N. I.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Živković, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zutshi, V.; Zwalinski, L.
Fecha de publicación:
07/2013
Editorial:
American Physical Society
Revista:
Physical Review D: Particles, Fields, Gravitation and Cosmology
ISSN:
1550-7998
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
A search for new particles that decay into top quark pairs (ttbar) is performed with the ATLAS experiment at the LHC using an integrated luminosity of 4.7 fb^-1 of proton-proton (pp) collision data collected at a center-of-mass energy sqrt(s)=7 TeV. In the ttbar --> WbWb decay, the lepton plus jets final state is used, where one W boson decays leptonically and the other hadronically. The ttbar system is reconstructed using both small-radius and large-radius jets, the latter being supplemented by a jet substructure analysis. A search for local excesses in the number of data events compared to the Standard Model expectation in the ttbar invariant mass spectrum is performed. No evidence for a ttbar resonance is found and 95% credibility-level limits on the production rate are determined for massive states predicted in two benchmark models. The upper limits on the cross section times branching ratio of a narrow Z' resonance range from 5.1 pb for a boson mass of 0.5 TeV to 0.03 pb for a mass of 3 TeV. A narrow leptophobic topcolor Z' resonance with a mass below 1.74 TeV is excluded. Limits are also derived for a broad color-octet resonance with Gamma/m = 15.3%. A Kaluza-Klein excitation of the gluon in a Randall-Sundrum model is excluded for masses below 2.07 TeV.
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Articulos de INST.DE FISICA LA PLATA
Articulos de INST.DE FISICA LA PLATA
Citación
Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; et al.; A search for ttbar resonances in the lepton plus jets final state with ATLAS using 4.7 fb-1 of pp collisions at √s = 7 TeV; American Physical Society; Physical Review D: Particles, Fields, Gravitation and Cosmology; 88; 1; 7-2013; 12004-12024
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