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SUSY Searches with One Photon at CMS

FSP-CMS Meeting 1-2 October 2012 DESY Zeuthen. SUSY Searches with One Photon at CMS. Valentina Sola ( Universität Hamburg ). GMSB and GGM Photon S earches at CMS Results and Limits. GMSB and GGM.  Gauge-Mediated SUSY Breaking (GMSB)

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SUSY Searches with One Photon at CMS

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  1. FSP-CMS Meeting 1-2 October 2012 DESY Zeuthen SUSY Searches with One Photon at CMS Valentina Sola (UniversitätHamburg) • GMSB and GGM • PhotonSearches at CMS • Results and Limits

  2. GMSB and GGM  Gauge-Mediated SUSY Breaking (GMSB) [ G. Giudice and R. Rattazzi, arXiv:hep-ph/9801271 ] = SUSY couples to normal matter through gauge interactions = Gravitino: LSP  General Gauge Mediation (GGM) [ P. Meade, N. Seiberg, D. Shih, arXiv:0801.3278 ] = neutralino NLSP a mixture of Bino, Wino and Higgsino = photon/Z+Gravitino or W+Gravitino final states -> one (or two) photon(s) + MET = focus on strong production: many jets LHC Physics Discussion - 10/9/2012

  3. GGM Phenomenology @ the LHC Neutralino NLSP mixture of Bino, Wino and Higgsino Bino-like NLSP:  Wino-like (co-)NLSP: Bino-Higgsino-like NLSP: R-parity is conserved -> 2 LSPs per event ★ MET is defining signature [ J. Ruderman, D. Shih, arXiv:1103.6083 ] LHC Physics Discussion - 10/9/2012

  4. GGM with One Photon at CMS • Final states with at least one photon • γ+Jets+MET • It includes the case of • Bino-Higgsino-like NSLP • γ + h + MET Results presented in ICHEP 2012 ∫Ldt = 4.04 fb-1 2012 Data @ √s = 8 TeV [ CMS Collaboration, PAS-12-018; AN-2012-154 ] LHC Physics Discussion - 10/9/2012

  5. Trigger Efficiency Analysis trigger: HLT_Photon70_CaloIdXL_PFHT400 Baseline triggers: HLT_Photon50_CaloIdVL (prescale = 900) HLT_Photon75_CaloIdVL (prescale = 150) HLT_PFHT350 (prescale = 1000) Trigger is fully efficient within an uncertainty of 4% LHC Physics Discussion - 10/9/2012

  6. Event Selection Photons ≥ 1 ET > 80 GeV Eiso(∆R<0.3) < 6 GeV |η| < 1.442 Jets ≥ 2 pT > 30 GeV |η| < 2.6 HT > 450 GeV MET > 100 GeV Jets = particle flow jets, anti-kT (R=0.5), photon rejected HT = scalar sum of pT of all jets with pT>40 GeV and |η|<3, no photon rejection LHC Physics Discussion - 10/9/2012

  7. Standard Model Backgrounds LHC Physics Discussion - 10/9/2012

  8. QCD Background Mis-measurement of MET in QCD processes -> direct di-photon, photon+jets, and multijet production with jets mimicking photons ✓ looser γ isolation requirements (γjet) orthogonal to signal selection ✓pT spectra reweighted in low MET region (MET<100 GeV) ✓ systematic uncertainty of 10% assigned LHC Physics Discussion - 10/9/2012

  9. Standard Model Backgrounds LHC Physics Discussion - 10/9/2012

  10. EWK Background • Events with true MET and an electron misidentified as a photon • -> compare Z→ee events to Z→eγ to obtain e→γ fake rate • Ratio of signal used to estimate fake rate fe→γ • pT > 80 GeV: fe→γ = 0.011 ± 0.002 (stat) ± 0.001 (syst) • Inclusive electron spectrum scaled by fe→γ to obtain EWK bkg LHC Physics Discussion - 10/9/2012

  11. Standard Model Backgrounds LHC Physics Discussion - 10/9/2012

  12. Standard Model Backgrounds MadGraph 50% uncertainty on the Xsec LHC Physics Discussion - 10/9/2012

  13. Single Photon MET Spectrum No excess observed over SM expectations Six bins in MET > 100 GeV used to set limits [100, 120, 160, 200, 270, 350, ∞) LHC Physics Discussion - 10/9/2012

  14. Single Photon Event Display LHC Physics Discussion - 10/9/2012

  15. Limit Calculation  Systematic errors = Uncertainty on trigger efficiency 4% = Theory errors: scale and PDF errors combined at each point and cross section varied by 1σ  Limit calculation = CLS method with likelihood-ratio test statistics at 95% = full propagation of errors = GGM Signal Monte Carlo (grid scan) Prospino used for NLO cross section LHC Physics Discussion - 10/9/2012

  16. Interpretation: Bino-like NLSP Bino-like GGM scan mχ0 = 375 GeV, msquark,gluino = 400-2000 GeV (step 80 GeV) sleptons and all gauginos except NLSP @ 3.5 TeV γ + ≥2 jets + MET γ + ≥2 jets + MET LHC Physics Discussion - 10/9/2012

  17. Interpretation: Wino-like NLSP Wino-like GGM scan mχ0 = 375 GeV, msquark,gluino = 400-2000 GeV (step 80 GeV) sleptons and all gauginos except NLSP @ 3.5 TeV γ + ≥2 jets + MET γ + ≥2 jets + MET LHC Physics Discussion - 10/9/2012

  18. Updated MET Spectrum Json: 27Aug ∫Ldt = 9.4 fb-1 CMSSW: 532patch1 LHC Physics Discussion - 10/9/2012

  19. Summary and Outlook  CMS analysis designed to cover a broad range of final state SUSY GMSB scenarios = Preliminary results with 4 fb-1 of 8 TeV data collected in 2012 = data-driven background estimate for QCD/EWK sources = no excesses seen over SM predictions  Exclusion limits set in bino- and wino-like neutralino NLSP = Bino like: msquark < 1.2 TeV, mgluino < 1.1 TeV excluded = Wino like: msquark < 900 GeV, mgluino < 800 GeV excluded  Results with full 2012 statistics foreseen in Moriond2013 = increased statistics = optimised analysis = b-tagging and angle variable investigation will be included LHC Physics Discussion - 10/9/2012

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