Search for supersymetric particles desintegrant itself in R-parite violee (coupling lambda_121) in a final state has three leptons

Thesis/Dissertation · Tue Jul 12 00:00:00 EDT 2005

DOI:https://doi.org/10.2172/875527· OSTI ID:875527

Magnan, Anne-Marie ^[1]

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1. Univ. Joseph Fourier Grenoble (France)

This thesis is dedicated to the study of the first data taken by the D0 detector during the Run II of the Tevatron. Supersymmetric particles have been search for in proton-antiproton collisions, with a center of mass energy of 1.96 TeV. In the framework of supersymmetry with R-parity violation, I have studied the pair production of Gauginos, leading to a pair of LSP (Χ$$0\atop{1}$$), each one decaying into eev_μ or eμv_e with a λ₁₂₁ coupling. The final state contains at least two electrons: I have thus paid special attention in this work to the methods concerning identification and mis-identification of electromagnetic particles, as well as reconstruction, triggering, and correction (of the reconstructed energy). In a selection of trileptons, with at least two electrons, and some transverse missing energy, we observed 0 event in the 350 pb^-1 of analyzed data, for 0,4$$+0,35\atop{0,05}$$(stat) ± 0,16 (sys) expected from the Standard Model contributions. In the signal considered in this analysis, the selection efficiency is around 12%. Results have been studied in two models: mSUGRA and MSSM. In mSUGRA model, limits on m_1/2 and lightest gauginos's masses have been obtained, with tanβ = 5, A₀ = 0, m₀ = 100 and 1000 GeV.c^-2 and both signs of μ. In MSSM, with the hypothesis of massive sfermions (1000 GeV.c^-2), we can exclude, at 95% Confidence Level, the region m_X1± < 200 GeV.c^-2, for all masses of Χ$$0\atop{1}$$ LSP.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 875527
• Report Number(s): FERMILAB-THESIS-2005-53; TRN: US0604992
• Country of Publication: United States
• Language: French

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
A CENTERS
EFFICIENCY
ELECTRONS
FERMILAB TEVATRON
HYPOTHESIS
LEPTONS
PAIR PRODUCTION
SPARTICLES
STANDARD MODEL
SUPERSYMMETRY
accelerators
D0
Run II
supersymmetry
R-parity violation
susygen
gamma121 coupling
electron identification
geometrical corrections