Search for the Supersymmetric Partner of the Top Quark in Dilepton Events, Internal Page

• Authors: Alexei Sedov and Virgil Barnes Alvin Laasanen Oscar González
• Blessed: March 19-th, 2009
• Godparents: none
  
  
• Data: Run II, 1 fb^-1
• Documentation: CDF note 9666
• Author's Analysis Web Page
• Public: Note PS, PDF,   and Web Page

Blessed Plots and Tables:

Results :
95% CL Bayesian exclusion limits EPS or GIF	Cross-section upper limits EPS or GIF	Exclusion limit w/o DØ EPS or GIF
Tables:
Pre-Signal definition/# of events EPS or GIF	Cuts for different Groups EPS or GIF
Pre-Signal clean up cut : any object (both leptons and jet) should be 20° away in φ from MET.
(N-1) Corlim expected upper limit vs Cut value plots for cut group d: (stop mass 170 GeV/c2 / sneutrino mass 60 GeV/c2) (Vertical lines show the cut values used for that particular cut group and are optimized for the entire cut group. Final cuts in each cut region are a compromise among tuning points.)
Met EPS or GIF	Ht EPS or GIF
PhiMet EPS or GIF	Pt2 EPS or GIF
Expected/observed plots: (blue dots are excluded, red squares are not excluded, green stars used for tuning cuts.)
Groups in stop/snu mass plane EPS or GIF	Expected (with group lines) EPS or GIF	Observed (with MC) EPS or GIF
Tables: Number of events after all cuts for different cut groups.
Groups a & d EPS or GIF	Groups b & c EPS or GIF
Met plots for pre-signal region :
ee EPS or GIF	eμ EPS or GIF
μμ EPS or GIF	All EPS or GIF
(N-1) Met Plots for cut group a :
ee EPS or GIF	eμ EPS or GIF
μμ EPS or GIF	All EPS or GIF
(N-1) Met Plots for cut group b :
ee EPS or GIF	eμ EPS or GIF
μμ EPS or GIF	All EPS or GIF
(N-1) Met Plots for cut group c :
ee EPS or GIF	eμ EPS or GIF
μμ EPS or GIF	All EPS or GIF
(N-1) Met Plots for cut group d :
ee EPS or GIF	eμ EPS or GIF
μμ EPS or GIF	All EPS or GIF
DY plots :
ee EPS or GIF Exp. 12335±63±923 Obs 12461	μμ EPS or GIF Exp. 6946±43±550 Obs 7111
Heavy flavor background is estimated from data, and is used for our control region comparisons but note that no HF(data) events survive our final analysis cuts . We define a "scaling region" with Dilepton Mass between [15,35] GeV/c2 where all MC-generated SM backgrounds are found to be negligible, except for DY, and for lepton+fake_lepton events estimated from data. Dilepton data are routinely required to have small impact parameter ("d0") to remove as much bb and cc as possible. Dilepton data in the above mass interval still show an excess over the sum of DY + "fakes". We attribute this excess to un-removed bb and cc events. We also attribute events failing these cleanup cuts, so-called "inverse d0 cut events" to bb and cc, and for each dilepton flavor combination, calculate the scale factor = "excess"/"inverse d0" (listed within each of the HF plots). We assume that the scale factor for a given flavor combination applies universally to events of that dilepton flavor, and model HF in any kinematic region by scaling the "inverse d0" events in that region. Similar plots exist for the remaining 657 pb-1 (two more data periods).
ee EPS or GIF	eμ EPS or GIF	μμ EPS or GIF
Definitions of Control Regions used in the analysis (y axis - Δφ between leptons) :
0 jets EPS or GIF	≥1 jet EPS or GIF
Z peak (ee, μμ with InvM∈(76,106), plots) is removed from the rest.
MET plots for Control regions with at least one jet: (Dashed lines represent uncertainties of background sums)
CR B1 ee EPS or GIF	CR B1 eμ EPS or GIF	CR B1 μμ EPS or GIF
CR C1 ee EPS or GIF	CR C1 eμ EPS or GIF	CR C1 μμ EPS or GIF