Abstract: In this analysis, we study the production of Standard Model processes from p ¯ p collisions at √s=1.96 TeV in the CDF II detector at Fermilab, in particular the content of the high pT dilepton events. The main processes considered are t¯ t, W W and Z → τ τ while the background processes are W + j ets, W γ , W Z , Z Z , Z/γ ∗ → ee, Z/γ ∗ → µµ. In the ﬁnal state of these processes, we require an electron and muon dilepton pair, and the other objects we expect to exist are neutrinos, which give our / ET (Missing Transverse Energy) variable, and jets, from hadronizing quarks.
Therefore, we plot these events in two 2-D phase spaces / ET vs. Nj ets and the / ET vs. ET (jets), which provide a nice separation of our main processes. We are then able to ﬁt our Monte Carlo simulated events to the data and extract the t¯ t, W W and Z → τ τ cross sections, as well as develop a quantitative likelihood for the consistency of the data to the SM hypothesis in this parameter space.
In using this method for the extraction of cross sections, our measurements us- ing 3.0fb−1 of eµ data are: σt¯ t = 8.20+1.17 −1.07 pb, σW W = 12.28 +2.05 −1.87 pb, and σZ →τ τ = 1513+173 −159 pb.
The results of quantifying the consistency of the data to the SM hypothesis yield no signiﬁcant deviations from SM expectations. Although not done in this iteration of the analysis, this technique could also be used to search for speciﬁc new physics dilepton signatures.The complete thesis is available here: Smith Thesis