Search for new physics with same-sign isolated dilepton events with jets and missing energy

Abstract

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.

Link to the 1 fb-1 study PAS CMS-PAS-SUS-11-010

Link to the 4.98 fb-1 study, CMS-SUS-11-010, arXiv:1205.6615, Submitted to PRL

Approved Tables and Plots from SUS-11-010 with 4.98 fb-1 ( click on plot to get .pdf )

Table	Abbreviated Caption
	Table 1: Observed number of events in data compared to the predicted background yields for the considered search regions. The uncertainties include the statistical and systematic components added in quadrature. Signal uncertainty of 20% is assumed for the upper limits on the event yields.

Figure	Abbreviated Caption
	Figure 1 : Selected SS di-lepton events in the various search regions displayed in HT -MET plane.
	Figure 2 : Summary of background predictions and observed yields in the various search regions. The shaded bands represent the total uncertainty on the background predictions.
	Figure 3 : Exclusion region in the CMSSM corresponding to the observed upper limits on the number events from new physics. The result of the previous analysis is shown to illustrate the improvement since

Approved Tables and Plots from SUS-11-010 as part of additional materials ( click on plot to get .pdf )

Figure	Abbreviated Caption
	Figure 1 : Exclusion contour (95% C.L.) in m( g)-m(χ0 ) plane for simplified model pp -> gluino gluino; gluino -> 2 q tau nu chi10
	Figure 2 : Tight-to-loose ratios using method for the non-prompt lepton control region for electrons
	Figure 3 : Tight-to-loose ratios using method for the non-prompt lepton control region for electrons
	Figure 4 : Tight-to-loose ratios using method for the non-prompt lepton control region for muons
	Figure 5 : Tight-to-loose ratios using method for the non-prompt lepton control region for muons
	Figure 6 : Tight-to-loose ratios using method for leptons from Z decays in the prompt lepton control region, for electrons, as a function of their transverse momenta
	Figure 7 : Tight-to-loose ratios using method for leptons from Z decays in the prompt lepton control region, for muons, as a function of their transverse momenta
	Figure 8 : Predicted and observed event yields as a function of HT for high pT leptons
	Figure 9 : Predicted and observed event yields as a function of HT for high pT leptons
	Figure 10 : Predicted and observed event yields as a function of MET for high pT leptons
	Figure 11 : Predicted and observed event yields as a function of MET for high pT leptons
	Figure 12 : Comparison of predicted and observed yields in the baseline selection of HT > 80 GeV, MET > 30 GeV for high pT leptons
	Figure 13 : Comparison of predicted and observed yields in the baseline selection of HT > 80 GeV, MET > 120 GeV for high pT leptons
	Figure 14 : Comparison of predicted and observed yields in the baseline selection of HT > 450 GeV, MET > 0 GeV for high pT leptons
	Figure 15 : Comparison of predicted and observed yields in the baseline selection of HT > 450 GeV, MET > 50 GeV for high pT leptons
	Figure 16 : Comparison of predicted and observed yields in the baseline selection of HT > 450 GeV, MET > 120 GeV for high pT leptons
	Figure 17 : Charge misreconstruction probability for electrons projected on eta measured in simulated events
	Figure 18 : Lepton selection efficiency as a function of pT , estimated in simulation for the LM6 SUSY benchmark point and corrected for simulation-to-data scale factors, for electrons and muons
	Figure 19 : Lepton selection efficiency as a function of pT , estimated in simulation for the LM6 SUSY benchmark point and corrected for simulation-to-data scale factors, for taus
	Figure 20 : Efficiency for an event to pass a given reconstructed MET threshold as a function of generator level MET
	Figure 21 : Efficiency for an event to pass a given reconstructed HT threshold as a function of generator level HT
	Figure 22 : Efficiency of the isolation requirement as a function of the cut value in electron muon final state
	Figure 23 : Efficiency of the isolation requirement as a function of the cut value in di-electron final state
	Figure 24 : Efficiency of the isolation requirement as a function of the cut value in di-muon final state
	Figure 25 : Efficiency of the isolation requirement (< 0.15) as a function of the cut value on MET for muons (red) and electrons (blue)
	Figure 26 : Isolation templates for electrons used for the prediction of single-fake lepton backgrounds in the Btag-and-Probe method
	Figure 27 : Isolation templates for muons used for the prediction of single-fake lepton backgrounds in the Btag-and-Probe method
	Figure 28 : Comparison of predicted and observed yields in the baseline selection of HT > 80 GeV, MET > 30 GeV for high pT leptons
	Figure 29 : Comparison of predicted and observed yields in the baseline selection of HT > 200 GeV, MET > 30 GeV for low pT leptons

-- SanjayPadhi - 25-Feb-2012