The results of a search for top squark (stop) pair production in final states with one isolated lepton, jets, and missing transverse momentum are reported. The analysis is performed with proton-proton collision data at ps = 8TeV collected with the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of 20 fb−1. The lightest supersymmetric particle (LSP) is taken to be the lightest neutralino which only interacts weakly and is assumed to be stable. The stop decay modes considered are those to a top quark and the LSP as well as to a bottom quark and the lightest chargino, where the chargino decays to the LSP by emitting a W boson. A wide range of scenarios with different mass splittings between the stop, the lightest neutralino and the lightest chargino are considered, including cases where the W bosons or the top quarks are off-shell. Decay modes involving the heavier charginos and neutralinos are addressed using a set of phenomenological models of supersymmetry. No significant excess over the Standard Model prediction is observed. A stop with a mass between 210 and 640GeV decaying directly to a top quark and a massless LSP is excluded at 95% confidence level, and in models where the mass of the lightest chargino is twice that of the LSP, stops are excluded at 95% confidence level up to a mass of 500 GeV for an LSP mass in the range of 100 to 150 GeV. Stringent exclusion limits are also derived for all other stop decay modes considered, and model-independent upper limits are set on the visible cross-section for processes beyond the Standard Model.

Search for top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in (Formula presented.)= 8 TeV pp collisions with the ATLAS detector

CONTA, CLAUDIO;DONDERO, PAOLO;FRATERNALI, MARCO;LIVAN, MICHELE;NEGRI, ANDREA;REBUZZI, DANIELA MARCELLA;RIMOLDI, ADELE;
2014-01-01

Abstract

The results of a search for top squark (stop) pair production in final states with one isolated lepton, jets, and missing transverse momentum are reported. The analysis is performed with proton-proton collision data at ps = 8TeV collected with the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of 20 fb−1. The lightest supersymmetric particle (LSP) is taken to be the lightest neutralino which only interacts weakly and is assumed to be stable. The stop decay modes considered are those to a top quark and the LSP as well as to a bottom quark and the lightest chargino, where the chargino decays to the LSP by emitting a W boson. A wide range of scenarios with different mass splittings between the stop, the lightest neutralino and the lightest chargino are considered, including cases where the W bosons or the top quarks are off-shell. Decay modes involving the heavier charginos and neutralinos are addressed using a set of phenomenological models of supersymmetry. No significant excess over the Standard Model prediction is observed. A stop with a mass between 210 and 640GeV decaying directly to a top quark and a massless LSP is excluded at 95% confidence level, and in models where the mass of the lightest chargino is twice that of the LSP, stops are excluded at 95% confidence level up to a mass of 500 GeV for an LSP mass in the range of 100 to 150 GeV. Stringent exclusion limits are also derived for all other stop decay modes considered, and model-independent upper limits are set on the visible cross-section for processes beyond the Standard Model.
2014
The Physics category includes resources of a broad, general nature that contain materials from all areas of physics, The category also includes resources specifically concerned with the following physics sub-fields: mathematical physics, particle and nuclear physics, physics of fluids and plasmas, quantum physics, and theoretical physics.
Esperti anonimi
Inglese
Internazionale
ELETTRONICO
2014
11
1
87
87
Hadron-Hadron Scattering; proton-proton scattering; supersymmetry; top squark; Nuclear and High Energy Physics
http://link.springer.com/journal/13130
2892
info:eu-repo/semantics/article
262
The ATLAS collaboration, Null; Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; Abouzeid, O. S.; Abra...espandi
1 Contributo su Rivista::1.1 Articolo in rivista
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/1107589
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