Search for top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in √<i>s</i>=8 TeV <i>pp</i> collisions with the ATLAS detector



Aad, G, Abbott, B, Abdallah, J, Khalek, S Abdel, Abdinov, O, Aben, R, Abi, B, Abolins, M, AbouZeid, OS, Abramowicz, H
et al (show 2880 more authors) (2014) Search for top squark pair production in final states with one isolated lepton, jets, and missing transverse momentum in √<i>s</i>=8 TeV <i>pp</i> collisions with the ATLAS detector. JOURNAL OF HIGH ENERGY PHYSICS, 11 (11). 118-.

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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 $\sqrt{s} = 8$ TeV 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 $640$ GeV 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.

Item Type: Article
Additional Information: 71 pages plus author list + cover page (94 pages total), 25 figures, 20 tables, submitted to JHEP, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2013-15/
Uncontrolled Keywords: Hadron-Hadron Scattering, proton-proton scattering, supersymmetry, top squark
Subjects: ?? QC ??
Depositing User: Symplectic Admin
Date Deposited: 31 Mar 2016 10:09
Last Modified: 16 Mar 2024 00:22
DOI: 10.1007/JHEP11(2014)118
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/2022512