Search for pair-produced third-generation squarks decaying via charm quarks or in compressed supersymmetric scenarios in pp collisions at √s=8 TeV with the ATLAS detector

Agustoni, Marco; Beck, Hans Peter; Cervelli, Alberto; Ereditato, Antonio; Gallo, Valentina; Haug, Sigve; Kruker, Tobias; Marti, Lukas; Meloni, Federico; Schneider, Basil; Sciacca, Gianfranco; Stramaglia, Maria; Stucci, Stefania Antonia; Weber, Michael (2014). Search for pair-produced third-generation squarks decaying via charm quarks or in compressed supersymmetric scenarios in pp collisions at √s=8 TeV with the ATLAS detector. Physical review. D - particles, fields, gravitation, and cosmology, D90(5), 052008. Melville, N.Y.: American Physical Society 10.1103/PhysRevD.90.052008

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Results of a search for supersymmetry via direct production of third-generation squarks are reported, using 20.3  fb −1 of proton-proton collision data at √s =8  TeV recorded by the ATLAS experiment at the LHC in 2012. Two different analysis strategies based on monojetlike and c -tagged event selections are carried out to optimize the sensitivity for direct top squark-pair production in the decay channel to a charm quark and the lightest neutralino (t 1 →c+χ ˜ 0 1 ) across the top squark–neutralino mass parameter space. No excess above the Standard Model background expectation is observed. The results are interpreted in the context of direct pair production of top squarks and presented in terms of exclusion limits in the m ˜t 1, m ˜ X0 1 ) parameter space. A top squark of mass up to about 240 GeV is excluded at 95% confidence level for arbitrary neutralino masses, within the kinematic boundaries. Top squark masses up to 270 GeV are excluded for a neutralino mass of 200 GeV. In a scenario where the top squark and the lightest neutralino are nearly degenerate in mass, top squark masses up to 260 GeV are excluded. The results from the monojetlike analysis are also interpreted in terms of compressed scenarios for top squark-pair production in the decay channel t ˜ 1 →b+ff ′ +χ ˜ 0 1 and sbottom pair production with b ˜ 1 →b+χ ˜ 0 1 , leading to a similar exclusion for nearly mass-degenerate third-generation squarks and the lightest neutralino. The results in this paper significantly extend previous results at colliders.

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:

Agustoni, Marco; Beck, Hans Peter; Cervelli, Alberto; Ereditato, Antonio; Gallo, Valentina; Haug, Sigve; Kruker, Tobias; Marti, Lukas; Meloni, Federico; Schneider, Basil; Sciacca, Gianfranco; Stramaglia, Maria; Stucci, Stefania Antonia and Weber, Michael

Subjects:

500 Science > 530 Physics

ISSN:

1550-7998

Publisher:

American Physical Society

Language:

English

Submitter:

Jan Dirk Brinksma-Albrecht

Date Deposited:

10 Jun 2015 10:11

Last Modified:

10 Jun 2015 10:11

Publisher DOI:

10.1103/PhysRevD.90.052008

Additional Information:

Kollaboration - Es sind nur die Berner Autoren namentlich erwähnt.

BORIS DOI:

10.7892/boris.68680

URI:

https://boris.unibe.ch/id/eprint/68680

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