Search for New Physics in the Missing Transverse Energy + Dijet Channel at CDF

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 2009

DOI:https://doi.org/10.2172/1128077· OSTI ID:1128077

MacQueen, Daniel ^[1]

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1. Univ. of Toronto, ON (Canada)

This thesis presents the results of a signature-based search for new physics using the exclusive dijet plus missing transverse energy data sample from 2 fb^-1 p$$\bar{p}$$ collisions at √s = 1.96 TeV collected from the Collider Detector at Fermilab (CDF). A study is made of the production of events with two high energy jets and large missing transverse energy (missing E_T, or E_T) in a kinematic regime requiring the scalar sum of the E_T of the two jets (referred to here as H_T) to be greater than 125 GeV and the event E_T to be above 80 GeV. A second kinematic region is also examined, with the E_T cut increased to 100 GeV and the H_T cut increased to 225 GeV. The number of events observed in the data is within 0.43 standard deviations of the expected number of background events in the low kinematic region, and with 0.34 standard deviations in the high kinematic region. Based on these results, 95% C.L. lower mass limits for scalar leptoquarks are extracted: 190 GeV/ c² for 1st generation, 190 GeV/ c² for 2nd generation, and 178 GeV/ c² for 3rd generation production. The results are also interpreted in terms of cross-section limits on generic minimal supersymmetric (MSSM) models.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1128077
• Report Number(s): FERMILAB-THESIS-2009-68
• Country of Publication: United States
• Language: English

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