Search for Squarks and Gluinos in MET+Jets, Internal Page

Search for Squarks and Gluinos in MET+Jets, Internal Page

We are reporting on the search for squarks and gluinos with a sample of 254 pb^-1. The cuts are optimized for the experimental signature of multijets and missing Et (MET) (R-parity conservation is assumed in this analysis). We basically require at least three jets with Et>25 GeV and |eta| < 2.0 (using cone algorithm with R=0.7) and some specific cuts to remove backgrounds. The analysis is performed defining a blind box for MET > 165 GeV and HT > 350 GeV (HT is the scalar sum of the Et of the three leading jets). The signal is generated in mSUGRA scenario using ISAJET and normalized to NLO with PROSPINO. The main backgrounds are QCD, Z/W+jets, WW and top. QCD is normalized by measuring the factor between data and MC in a region where only QCD is dominant. W's and Z's are normalized to NLO with MCFM program and top is normalized to the theoretical cross section. We are applying specific cuts to reduce their contributions. At the very end we are expecting 4.08 +- 0.57 events of background. When opening the blind box, we find 3 events.
Currently we are working on stablishing new limits in the squark-gluino plane.

Authors: Xavier Portell, Mario Martínez and Carlos Sánchez
Blessed: April 14th, 2005
Data: Run II, 254 pb^-1
Public: Note in progress

Blessed Plots and Tables:

Basic cuts
	Data before and after applying the 3 jets requirement and the rest of the basic cuts to reduce beam and muon backgrounds. EPS or GIF.
After opening the Blind Box
	Data and all backgrounds after applying all the cuts except the MET cut. Notice that each background is the sum of the previous. EPS or GIF.
	Data and all backgrounds after applying all the cuts except the HT cut. Notice that each background is the sum of the previous. EPS or GIF.
	XY view of one of the events found inside the blind box. EPS or GIF.
	Lego plot of the same event found inside the blind box. EPS or GIF.
QCD measurement
	QCD data and MC in a region where only QCD is dominant. EPS or GIF.
	Fraction of QCD data and MC in a region where only QCD is dominant. The factor is close to one. EPS or GIF.

Table of expected events and significancies
	Expected number of events for the three points in study and for the background. It is also shown the different expectations for the signal after the cuts and the signficancies per each of the points. EPS or GIF.

Page page: http://www-cdf.fnal.gov/internal/physics/exotic/physics/r2a/00000000.template/index.html was last updated October 6th, 2004 by Stephan Lammel.
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