Status of GMSB photons analysis Shilei Zang Bernadette Heyburn, Uriel Nauenberg University of Colorado, Boulder SUSYBSM WG3/WG4 meeting, 24 Aug. 2007

2 Outline Photonic GMSB sample Generator studies for signal events, and comparison with ORCA results Reconstructed objects Signal efficiency and background study Summary and next to do

3 Photonic GMSB Sample Bob Hirosky’s GMSB sample (prompt photon). Gen-Sim: CMSSW_1_4_6; Dig-Rec: CMSSW_1_5_3. About 8250 events (I used 7999 evts for this report). Lmd=100TeV; M_mess=2Lmd; N=1; tanBeta=15; sig(mu)=+1; M_top=175GeV; C_grav=1. (ctau=0.115mm, or ctau=0?) MSEL=0 and MSUB(244)=1, only gg  ~g~g generated. (xSection~0.492pb)  Francesco’s GMSB sample (prompt photon). CMKIN  OSCAR  ORCA  Same GMSB parameters as above Bob’s.  MSEL=39, all SUSY processes included. xSection(total SUSY)~0.439pb; xSection(gg  ~g~g)~0.05pb.  All the plots on Francesco’s sample are provided by Francesco.

4 GMSB photons high pT photons large MET due to gravitinos multi-jets Experimental signature

5 Generator studies for signal events Number of generator photons P T and Eta of generator photons MET from gravitinos and from gen Quarks from SUSY particle Neutralino’s vertex and flight distance Start from generator level in order to check the GMSB sample, compare with ORCA results, and define the selection criteria for the future analysis.

6 Number of generator photons Photons from neutralino decay: BR of neutralino from Isajet: 2 photons ~90.14% 1 photon ~9.58% 0 photon ~0.29% BR(LSP+photon)~95% BR(LSP+Z0)~3% BR(LSP+ e+e-)~2% BR(LSP+H0)~10 -4 % 95%*95%=90.25% 2*5%*95%=9.5% 5%*5%=0.25% Number of photons from NLSP decay per event

7 P T of generator photons P T (peak)~100GeVP T (peak)~40GeV 1 st photon CMSSW 2 nd photon CMSSW 71.7% P T >90GeV79.5% P T >30GeV 1 st photon ORCA 2 nd photon ORCA PTPT PTPT

8 Eta of generator photons ~89% in barrel ~78% in barrel Barrel: |eta|< st photon CMSSW 2 nd photon CMSSW 1 st photon ORCA 2 nd photon ORCA Eta

9 MET from gravitinos and from gen MET from neutrinos and gravitinos. peak~100GeVpeak~140GeV CMSSW ORCA

10 MET from gravitinos vs from gen CMSSW

11 Quarks from SUSY particle Mother of selected quarks is a SUSY particle. Sample includes only gg  ~g~g process, and BR(~g  SUSY+qqbar)~98.6%, and 98.6%*98.6%=97.2%. quarks(4,6,8,10)~97% Number of quarks from SUSY decay Type of quarks (pid) d u s c b 4 quarks ~91.7% 2 quarks ~3.1% 0 quark ~0.025% 6 quarks ~4.5% 8 quarks ~0.64% qbar 10 quarks ~0.038%

12 Number of quarks per event CMSSW result: Sample includes only gg  ~g~g process ORCA result: Sample includes all SUSY processes CMSSWORCA Number of quarks from SUSY particle

13 P T and Eta of quarks P T (peak)~160GeV CMSSW Eta PTPT 87.9% P T >100GeV ORCA PTPT PTPT

14 Neutralino’s Vertex Vetex smeared with Gauss (sigX=sigY=0.0015cm, sigZ=5.3cm) Gravitino’s vetex minus Neutralino’s vetex equals exactly zero. So ctau=0 exactly? (ctau should equal mm?) VxVy Vz

15 Reconstructed objects Use SusyAnalyzer under CMSSW_1_5_3 The reconstructed objects are filtered, cleaned, and driven by SusyAnalyzer. SusyAnalyzer’s default parameters (cuts) are used: photonEtaMax=2.5; photonPtMin=20GeV; jetPtMin=30GeV. Multiplicity of jets and photons P T and eta of jets and photons MET from Calorimeter and Recoil

16 Multiplicity of jets/photons and Pt of jets Number of jets Number of photons 62.9% >=2 phorons P T of the1 st jet P T of the 2 nd jet

17 P T and Eta of photons P T (peak)~100GeVP T (peak)~45GeV 1 st photon 2 nd photon PTPT PTPT Eta

18 MET from Calorimeter, Recoil, and Gen MetCaloMetRecoil MetRecoil/MetCaloMetRecoil/MetGen peak~110GeVpeak~120GeV mean~1.02mean~0.81

19 Signal efficiency Francesco’s 2 gamma selection: P T (1 st gamma)>90GeV P T (2 nd gamma)>30GeV Abs(eta)<1.479 for both of the gamma (barrel) events selected with Francesco’s 2 gamma selection. Further require MetRecoil>130GeV  1796 events. Signal efficiency= 1796/7210 =24.9%

20 MET distribution after Francesco’s 2 gamma selection Final MET of signal sample

21 Background study QCD: 1) qcd jets (0<pT_hat<4000GeV) 2) gamma jet (pT_hat>40GeV) EW background 1) W+jets and Z+jets (0<pT_hat<2200GeV) 2) ttbar inclusive Others 1) W+gamma 2) Z+gamma 3) WW, ZZ, WZ Francesco listed the following bkg need to analyze: First test with PhotonJets_Pt_300_500. xSection(bkg)=8.2pb. xSection(GMSB)=0.492pb. Scale factor: 7999/(100000*0.492/8.2)=1.33

22 MET of GMSB and Bkg MET of PhotonJets_Pt_ 300_500 (scaled) MET of GMSB Further require MetRecoil>130GeV  Signal efficiency=24.9%; Bkg(PhotonJets) efficiency = 0.189%

23 Summary and next to do Generator signal events studied to test the sample and compare with ORCA results. CMSSW results are similar as ORCA’s. Reconstructed objects simply analyzed to understand them and SusyAnalyzer Tried a background analysis With Francesco’s cuts, give the efficiency of the signal and of the background sample. Summary Next to do Further analyze the reconstructed objects after matching with generator particles. Find a set of analysis variables to select 2 gamma, and determine the cuts Generate some GMSB second vertex (not prompt) photons samples. Establish our analysis strategy for GMSB second vertex photons analysis.

24 Thank you!