Search for pair production of scalar top quarks decaying to aτ lepton and a b quark in 1.96 TeV p$$\bar{p}$$ collisions

Thesis/Dissertation · Thu May 01 00:00:00 EDT 2008

DOI:https://doi.org/10.2172/927939· OSTI ID:927939

Vadim Khotilovich

I present the results of a search for pair production of scalar top quarks ($$\tilde{t}$$₁) in an R-parity violating supersymmetric scenario using 322 pb^-1 of p{bar p} collisions at √s = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. I assume each $$\tilde{t}$$₁ decays into a {tau} lepton and a b quark, with branching ratio {beta}, and search for final states containing either an electron or a muon from a leptonic τ decay, a hadronically decaying τ lepton, and two or more jets. Two candidate events pass my final selection criteria, consistent with the expectation from standard model processes. I present upper limits on the cross section times branching ratio squared σ($$\tilde{t}$$₁$$\tilde{t}$$₁) x β² as a function of the stop mass m($$\tilde{t}$$₁). Assuming β = 1, I set a 95% confidence level limit m($$\tilde{t}$$₁) > 153 GeV=c². These limits are also fully applicable to the case of a pair produced third generation scalar leptoquark that decays into a τ lepton and a b quark.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 927939
• Report Number(s): FERMILAB-THESIS-2008-05; TRN: US0804753
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
B QUARKS
BRANCHING RATIO
CROSS SECTIONS
DECAY
ELECTRONS
FERMILAB COLLIDER DETECTOR
LEPTONS
MUONS
PAIR PRODUCTION
SCALARS
STANDARD MODEL
T QUARKS
TAU PARTICLES
Experiment-HEP