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

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

We are reporting on the search for squarks and gluinos in a mSUGRA scenario assuming R-parity conservation with a sample of 371 pb^-1 of CDF Run II data. The analysis is optimized for three jets and missing transverse energy (MET) signature. Three different set of cuts are defined to increase sensitivity in different zones with increasing gluino mass. The thresholds for the transverse energy (ET) of the jets, the MET and the scalar sum of the ET of the three main jets (HT) are quoted below:

Type Zone A: ET1 > 95 GeV ; ET2 > 55 GeV ; ET3 > 25 GeV ; MET > 75 GeV ; HT > 230 GeV
Type Zone B: ET1 > 120 GeV ; ET2 > 70 GeV ; ET3 > 25 GeV ; MET > 90 GeV ; HT > 280 GeV
Type Zone C: ET1 > 140 GeV ; ET2 > 100 GeV ; ET3 > 25 GeV ; MET > 120 GeV ; HT > 330 GeV

No excess with respect to Standard Model predictions is found. A preliminary 95% C.L. exclusion plane has been produced where masses below 380 GeV/c^2 are excluded in the region where gluino and squark masses are similar.

Authors: Xavier Portell, Mario Martínez and Carlos Sánchez
Blessed: April 20th, 2006
Data: Run II, 371 pb^-1
Documentation:
- Webpage of the previous blessing of 250pb^-1

Blessed Plots:

Results
	CDF Run II exclusion limits at 95% C.L. The green area is the observed limit and the dashed line corresponds to the MC expected limit. EPS or GIF.
	CDF Run II and D0 Run II exclusion limits at 95% C.L. EPS or GIF.
	Signal cross section as a function of squark mass when the gluino mass is ~235 GeV/c^2. 95% C.L. lines and theoretical uncertainties are also shown. EPS or GIF.
	Signal cross section as a function of squark mass when the gluino mass is ~255 GeV/c^2. 95% C.L. lines and theoretical uncertainties are also shown. EPS or GIF.
	Signal cross section as a function of the gluino mass when the squark and gluino masses are similar. 95% C.L. lines and theoretical uncertainties are also shown. EPS or GIF.

Data and Different MC Contributions
	MET distribution for data and SM backgrounds after applying all the cuts (Type Zone A). The MET cut is marked with an arrow. EPS or GIF.
	HT distribution for data and SM backgrounds after applying all the cuts (Type Zone A). The HT cut is marked with an arrow. EPS or GIF.
	MET distribution for data and SM backgrounds after applying all the cuts (Type Zone B). The MET cut is marked with an arrow. EPS or GIF.
	HT distribution for data and SM backgrounds after applying all the cuts (Type Zone B). The HT cut is marked with an arrow. EPS or GIF.
	MET distribution for data and SM backgrounds after applying all the cuts (Type Zone C). The MET cut is marked with an arrow. EPS or GIF.
	HT distribution for data and SM backgrounds after applying all the cuts (Type Zone C). The HT cut is marked with an arrow. EPS or GIF.

Data and MC Comparisons
	MET distribution for data and all backgrounds with the statistic and systematic uncertainties after all the cuts (Type Zone A). The MET cut is marked with an arrow. The non-QCD contribution is also shown together with the signal distribution for Msquark ~ Mgluino ~ 252 GeV/c^2. EPS or GIF.
	HT distribution for data and all backgrounds with the statistic and systematic uncertainties after all the cuts (Type Zone A). The HT cut is marked with an arrow. The non-QCD contribution is also shown together with the signal distribution for Msquark ~ Mgluino ~ 252 GeV/c^2. EPS or GIF.
Data and MC Reversing QCD Rejection Cuts
	MET distribution for data and all backgrounds with statistic plus systematic uncertainties (Type Zone A). The cut to reject QCD has been reverted in order to enhance this background contribution. The rest of cuts have been applied except the MET cut. The non-QCD contribution is also shown together with the signal distribution for Msquark ~ Mgluino ~ 252 GeV/c^2. EPS or GIF.
	HT distribution for data and all backgrounds with statistic plus systematic uncertainties (Type Zone A). The cut to reject QCD has been reverted in order to enhance this background contribution. The rest of cuts have been applied except the HT cut. The non-QCD contribution is also shown together with the signal distribution for Msquark ~ Mgluino ~ 252 GeV/c^2. EPS or GIF.
Data and MC Reversing Electron Rejection Cuts
	MET distribution for data and all backgrounds with statistic plus systematic uncertainties (Type Zone A). The cut to reject electrons has been reverted in order to enhance this type of background contribution. The rest of cuts have been applied except the MET cut. The non-QCD contribution is also shown together with a representative point from this zone. EPS or GIF.
	HT distribution for data and all backgrounds with statistic and systematic uncertainties (Type Zone A). The cut to reject electrons has been reverted in order to enhance this type of background contribution. The rest of cuts have been applied except the HT cut. The non-QCD contribution is also shown together with a representative point from this zone. EPS or GIF.
Data and MC Reversing Muon Rejection Cuts
	MET distribution for data and all backgrounds with statistic plus systematic uncertainties (Type Zone A). The cut to reject muons has been reverted, by asking at least one isolated track, in order to enhance this type of background contribution. The rest of cuts have been applied except for the MET cut. The non-QCD contribution is also shown together with a representative point from this zone. EPS or GIF.
	HT distribution for data and all backgrounds with statistic plus systematic uncertainties (Type Zone A). The cut to reject muons has been reverted, by asking at least one isolated track, in order to enhance this type of background contribution. The rest of cuts have been applied except for the HT cut. The non-QCD contribution is also shown together with a representative point from this zone. EPS or GIF.
Data and MC After Pre-Selection Cuts Only
	MET distribution for data and all backgrounds with statistic plus systematic uncertainties after the pre-selection cuts only. EPS or GIF.
	HT distribution for data and all backgrounds with statistic plus systematic uncertainties after the pre-selection cuts only EPS or GIF.
	Number of isolated tracks distribution for data and all backgrounds with the statistical plus systematic band after the pre-selection cuts only. EPS or GIF.

Other Supporting Blessed Plots and Tables:

Signal Plane
	Signal Generation Plane. EPS or GIF.
Optimization examples
	HT distribution for Signal (S), Background (B) and S+B for Mgluino ~ Msquark ~ 295 GeV/c^2. The arrow indicates the result of the threshold optimization. EPS or GIF.
	HT distribution for Signal (S), Background (B) and S+B for Mgluino ~ 295 GeV/c^2 and Msquark ~ 420 GeV/c^2. The arrow indicates the result of the threshold optimization. EPS or GIF.
	Significance for different HT thresholds for Mgluino ~ Msquark ~ 295 GeV/c^2. The arrow indicates the result of the threshold optimization. EPS or GIF.
	Significance for different HT thresholds for Mgluino ~ 295 GeV/c^2 and Msquark ~ 420 GeV/c^2. The arrow indicates the result of the threshold optimization. EPS or GIF.
Final Background contributions
	Background relative contributions after all cuts have been applied for Zone A. EPS or GIF.
	Background relative contributions after all cuts have been applied for Zone B. EPS or GIF.
	Background relative contributions after all cuts have been applied for Zone C. EPS or GIF.

Table of data and expected background events
	Data and expected background events for the three cut thresholds in study. Uncertainties are statistical and systematics. EPS or GIF.