Search for the Standard Model Higgs boson produced in association with top quarks and decaying into bb ¯ in pp collisions at √s = 8 TeV with the ATLAS detector

ATLAS, Collaboration; Beck, Hans Peter; Cervelli, Alberto; Ereditato, Antonio; Haug, Sigve; Kabana, Sonja; Meloni, Federico; Mullier, Geoffrey André Adrien; Pretzl, Klaus-Peter; Stramaglia, Maria Elena; Stucci, Stefania; Weber, Michael (2015). Search for the Standard Model Higgs boson produced in association with top quarks and decaying into bb ¯ in pp collisions at √s = 8 TeV with the ATLAS detector. European physical journal. C - particles and fields, C75(7), p. 349. EDP Sciences 10.1140/epjc/s10052-015-3543-1

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A search for the Standard Model Higgs boson produced in association with a pair of top quarks, tt ¯ H , is presented. The analysis uses 20.3 fb¯¹ of pp collision data at √s = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H to bb ¯ decay mode and uses events containing one or two electrons or muons. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities. A neural network is used to discriminate between signal and background events, the latter being dominated by tt ¯ +jets production. In the single-lepton channel, variables calculated using a matrix element method are included as inputs to the neural network to improve discrimination of the irreducible tt ¯ +bb ¯ background. No significant excess of events above the background expectation is found and an observed (expected) limit of 3.4 (2.2) times the Standard Model cross section is obtained at 95% confidence level. The ratio of the measured tt ¯ H signal cross section to the Standard Model expectation is found to be μ = 1.5 ± 1.1 assuming a Higgs boson mass of 125 GeV.

Item Type:

Journal Article (Original Article)

Division/Institute:

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

UniBE Contributor:

Beck, Hans Peter; Cervelli, Alberto; Ereditato, Antonio; Haug, Sigve; Meloni, Federico; Mullier, Geoffrey André Adrien; Pretzl, Klaus-Peter; Stramaglia, Maria Elena; Stucci, Stefania and Weber, Michael

Subjects:

500 Science > 530 Physics

ISSN:

1434-6044

Publisher:

EDP Sciences

Language:

English

Submitter:

Annette Krebs-Wegenast

Date Deposited:

07 Sep 2016 15:28

Last Modified:

11 Sep 2016 02:12

Publisher DOI:

10.1140/epjc/s10052-015-3543-1

ArXiv ID:

1503.05066

Additional Information:

Kollaboration - Es sind nur die Berner Autoren namentlich erwähnt

BORIS DOI:

10.7892/boris.87644

URI:

https://boris.unibe.ch/id/eprint/87644

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