Dissertation/Thesis Abstract

Search for Direct Gaugino Production Decaying to Two Leptons and Missing Transverse Momentum at ATLAS with Center of Mass Energy = 7 TeV
by Toggerson, Brokk, Ph.D., University of California, Irvine, 2012, 174; 3540399
Abstract (Summary)

A search for the electroweak production of gauginos decaying into two leptons and missing transverse momentum, [special characters omitted], is presented using pp collisions at [special characters omitted] = 7 TeV produced by the LHC and recorded by the ATLAS detector corresponding to an integrated luminosity of 4.7 fb−1. Standard Model backgrounds are estimated using a combination of semi-data-driven techniques where possible, and Monte Carlo simulation. No significant excess in data with respect to the Standard Model prediction is observed in any of the four signal regions: opposite-sign dileptons with a jet veto and [special characters omitted], same-sign dileptons with a jet veto and [special characters omitted], opposite-sign dileptons in association with jets, or a signal region requiring opposite sign dileptons and using kinematic properties of the event to remove tt¯ and WW backgrounds. In addition to model-independent limits, limits are set in both simplified models and in the context of the phenomenological Minimally Supersymmetric Standard Model. Using the simplified model paradigm, wino-based charginos, decaying through an intermediate on-shell slepton or sneutrino to a stable 10 GeV neutralino, are excluded for chargino masses between 110 and 340 GeV. For the case of associatively produced mass-degenerate charginos and neutralinos both decaying via on-shell sleptons or sneutrinos to stable 10 GeV neutralinos, the chargino and neutralino masses of 80-260 GeV are excluded.

Indexing (document details)
Advisor: Taffard, Agnes C.
Commitee: Rajaraman, Arvind, Whiteson, Daniel
School: University of California, Irvine
Department: Physics - Ph.D.
School Location: United States -- California
Source: DAI-B 74/02(E), Dissertation Abstracts International
Subjects: Particle physics
Keywords: Dilepton, Gauginos, Large Hadron Collider, Missing transverse momentum, Supersymmetry
Publication Number: 3540399
ISBN: 978-1-267-65238-6
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