A search for ttbar resonances in the lepton plus jets final state with ATLAS using 4.7 fb⁻¹ of collisions at sqrt(s) = 7 TeV

ATLAS, Collaboration; Agustoni, Marco; Ancu, Lucian; Battaglia, Andreas; Beck, Hans Peter; Borer, Claudia; Cervelli, Alberto; Ereditato, Antonio; Gallo, Valentina; Haug, Sigve; Kabana, Sonja; Kruker, Tobias; Marti, Lukas; Pretzl, Klaus-Peter; Schneider, Basil; Sciacca, Gianfranco; Weber, Michael (2013). A search for ttbar resonances in the lepton plus jets final state with ATLAS using 4.7 fb⁻¹ of collisions at sqrt(s) = 7 TeV. Physical review. D - particles, fields, gravitation, and cosmology, 88(1), 012004. Melville, N.Y.: American Physical Society 10.1103/PhysRevD.88.012004

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A search for new particles that decay into top quark pairs (t (t) over bar) 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 root s = 7 TeV. In the t (t) over bar) -> WbWb decay, the lepton plus jets final state is used, where one W boson decays leptonically and the other hadronically. The t (t) over bar) 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 t (t) over bar) invariant mass spectrum is performed. No evidence for a t (t) over bar) 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 m 15.3%. A Kaluza-Klein excitation of the gluon in a Randall-Sundrum model is excluded for masses below 2.07 TeV.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP)
10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)

UniBE Contributor:

Agustoni, Marco; Ancu, Lucian; Battaglia, Andreas; Beck, Hans Peter; Borer, Claudia; Cervelli, Alberto; Ereditato, Antonio; Gallo, Valentina; Haug, Sigve; Kruker, Tobias; Marti, Lukas; Pretzl, Klaus-Peter; Schneider, Basil; Sciacca, Gianfranco and Weber, Michael

Subjects:

500 Science > 530 Physics

ISSN:

1550-7998

Publisher:

American Physical Society

Language:

English

Submitter:

Andrea Stettler

Date Deposited:

11 Sep 2014 09:34

Last Modified:

31 Aug 2015 09:49

Publisher DOI:

10.1103/PhysRevD.88.012004

Web of Science ID:

000322145600002

ArXiv ID:

1305.2756v2

Additional Information:

Kollaboration - Es sind nur die Berner Autoren namentlich erwähnt.

BORIS DOI:

10.7892/boris.58438

URI:

https://boris.unibe.ch/id/eprint/58438

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