Search for charginos nearly mass degenerate with the lightest neutralino based on a disappearing-track signature in pp collisions at (√s)=8 TeV with the ATLAS detector

Allison, Lee and Barton, Adam and Borissov, Guennadi and Bouhova-Thacker, Eva and Catmore, James and Chilingarov, Alexandre and Dearnaley, William and Fox, Harald and Grimm, Kathryn and Henderson, Robert and Hughes, Gareth and Jones, Roger William Lewis and Kartvelishvili, Vakhtang and Long, Robin and Love, Peter and Maddocks, Harvey and Smizanska, Maria and Walder, James (2013) Search for charginos nearly mass degenerate with the lightest neutralino based on a disappearing-track signature in pp collisions at (√s)=8  TeV with the ATLAS detector. Physical Review D, 88 (11). ISSN 1550-7998

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Abstract

A search is presented for direct chargino production based on a disappearing-track signature using 20.3  fb−1 of proton-proton collisions at s√=8  TeV collected with the ATLAS experiment at the LHC. In anomaly-mediated supersymmetry breaking (AMSB) models, the lightest chargino is nearly mass degenerate with the lightest neutralino and its lifetime is long enough to be detected in the tracking detectors by identifying decays that result in tracks with no associated hits in the outer region of the tracking system. Some models with supersymmetry also predict charginos with a significant lifetime. This analysis attains sensitivity for charginos with a lifetime between 0.1 and 10 ns, and significantly surpasses the reach of the LEP experiments. No significant excess above the background expectation is observed for candidate tracks with large transverse momentum, and constraints on chargino properties are obtained. In the AMSB scenarios, a chargino mass below 270 GeV is excluded at 95% confidence level.

Item Type:
Journal Article
Journal or Publication Title:
Physical Review D
Additional Information:
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. © 2013 CERN, for the ATLAS Collaboration
ID Code:
68345
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Deposited On:
24 Jan 2014 05:54
Refereed?:
Yes
Published?:
Published
Last Modified:
31 Mar 2020 02:59