Inclusive SUSY Reach of CMS during Early LHC Running in the Jets + MET + N Leptons topology

1. Inclusive SUSY Reach of CMS during Early LHC Running in the Jets + MET + N Leptons topology Bobby Scurlock Darin Acosta Richard Cavanaugh University of Florida

2. Overview • Motivation • Phase 1 : Prelude • Establish “full-chain” • Verify CMS Note 98-073 with “full-chain” • Phase 2 : Main emphasis • Study systematic effects on reach • Establish reach scenarios • Phase 3 • Write contributions for Physics TDR • Defend PhD !

3. Our Interest • Extend earlier Florida JetMET BSM analysis efforts from CDF to CMS • Collaborate with other CMS members: • Florida Colleagues on SS 2μ Inclusive SUSY Reach Analysis: • A.Drozdetski, Y.Pakhotin, P.Bartalini, D.Acosta, G.Mitselmakher • JetMET Group: • Haifeng Pi, Arno Heister, Rob Harris, et al. • UF SUSY/BSM Theorists: • P. Ramond, R. Field, and K. Matchev • Focus on early (~10 fb-1) LHC physics • Establish realistic reach expectations • Study systematic effects • Consider “What if…” scenarios • Probe quasi-model-independent reaches

4. Earlier CMS Work Abdullin & Charles (CMS Note 98-073) • Used Fast Sim. (CMSJET) of CMS detector • Established reasonable criteria for signal selection & background rejection, and sensible expectations for signal & background distributions • Studied some simple systematics • Signal & Background variations • Pile-up effects • QCD background was (remains) a serious challenge • DAQ TDR Gives idea of Level-1 Trigger and HLT requirements for good efficiency for SUSY events over several representative points in mSUGRA space

5. What if… …we assume a well understood detector? • 0 leptons + Jets + MET has most significant reach …we assume, e.g., that calorimeter responses are not well understood? • Would n muons + Jets + MET be more significant? • If so, at what level of jet energy scale uncertainty? Abdullin & Charles (CMS Note 98-073)

6. Establish “full-chain” analysis CMKIN 3+ OSCAR 3+ ORCA 8+ Develop RootMaker Defining our own currently Investigating JetMET ntuple Run on Digis (baseline) Run on DSTs (when stable) “Full-chain” important for systematic studies ! Modify physics process Perturb detector response Change reconstruction RecCollections minbias DST Digis,Assocs Stream signal Phase 1 : Analysis set-up OSCAR CMKIN Simulation Generation MCinfo,G4 Vtx, Tk SimHits HEPEVTNtuple MC generator Production ORCA Analysis or Calibration Reconstruction Digitization RecReader SimReader RecReader Histo/Tree Histo/Tree RecColl, Digis Histo/Tree Digis Histo/Tree RecColl, Digis User Production RootMaker Tree

7. Phase 1 : Digi Datasets - Signal Need more signal !

8. Phase-1 : Digi Datasets – EW Background Z+jets lagging a bit !

9. Phase-1 : Digi Datasets – QCD Background Need inclusive TTbar ! Need more high PT QCD !

10. Phase 1 : Digi Datasets - Higher order EW Background Location of inclusive WW, ZW ?

11. Phase 1 : Confirm Abdullin & Charles • Examine distributions after full simulation: • Jet multiplicity, ET, ETMiss, Δφ(ETjet1, ETMiss), etc… • Simple optimised cut set based on significance = Ns / √(Ns+Nb) • Try/use initial selection criteria from Abdullin & Charles • Produce preliminary expected reach in m0 vs m1/2 plane • 10 fb-1 • 100 fb-1 • Ultimately, would like to limit number of cut sets used, by carving out regions in mSUGRA space rather than optimizing cuts for each particular point – this reduces systematics…

12. N = (εSσS + εBσB) L Estimate uncertainties in cross-section σB Treat QCD differently from EW K-Factors Guess at uncertainties in Luminosity L Estimate uncertainties in efficiencies εS , εB MC statistics Detector Effects Reconstruction Effects JetMET Muon Electron Theory Examine uncertainties on backgrounds in control regions Phase 2 : Systematics: The main emphasis of this work

13. Phase 2 : Systematics – Triggers • Jet Corrections at L1? • Trigger Efficiencies: • Jet+ETMiss • Muons • Electrons • Inclusive SUSY

14. Phase 2 : Systematics – Reconstruction of Physics Objects • Jets: • E/HCAL Calibration • Tracking Uncertainties • ET vs. h • ETMiss: • Calibration • Fake Rates • Azimuthal Isolation • Muons • B-Field • Detector Alignment • Brem • Electrons • B-Field • ECAL Calibration • Brem

15. Phase 2 : Significance Estimator • Estimate reach at 95% CL using likelihood • Include systematic effects via convolution Likelihood for SUSY Signal hypothesis, given Experimental Data and assuming knowledge of Standard Model Background Systematic Gaussian PDFs Statistical Poisson PDF

16. Phase 2 : Quasi-model-independent studies • “What if…” mSUGRA is not the SUSY breaking model realised in Nature? • Investigate more model independent approaches for setting reaches • Physical squark and gluino masses • Cross-section x BRs • Validate against several different SUSY models at generator level

17. Potentially very useful for: mSUGRA parameter sweeps Estimates of systematic effects which are otherwise to costly Investigate Distributions of Physics Objects: JetMET: ET of leading jet, ET of next leading jet, MET of event, Jet multiplicity, etc… Muons: PT of leading muon, PT of next leading muon, Muon isolation, etc… Electron: ET of leading electron, ET of next leading electron, Electron isolation, etc... Phase 2 : FAMOS

18. Synergy with Inclusive SS 2μ SUSY Reach • Authors: • Alexei Drozdetski (see today’s talk), Yuriy Pakhotin, Paolo Bartalini, Darin Acosta, Guenakh Mitselmakher • Many systematics are the same (or similar) for both analyses • Division of labor • Agree on a common Root Tree • Etc…

19. Conclusions • Interested in conducting inclusive SUSY search in the Jets + MET + Leptons topology to establish realistic reach expectations • In process of mastering analysis chain and crating analysis tools • Will conduct sanity checks against previous studies • Consider various “What if …” scenarios, and systematic effects • Would like to evolve to a model independent study