1 / 19

SPS8 Diphoton Analysis Update

SPS8 Diphoton Analysis Update. Daniel Damiani 29 April 2010. Full Simulation SPS8 Point. There is now a full simulation/official production SPS8 point available on the grid mc09_7TeV.114007.SPS8_110_jimmy_susy.merge.AOD.e530_s765_s767_r1207_r1210

esben
Télécharger la présentation

SPS8 Diphoton Analysis Update

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SPS8 Diphoton Analysis Update Daniel Damiani 29 April 2010

  2. Full Simulation SPS8 Point • There is now a full simulation/official production SPS8 point available on the grid • mc09_7TeV.114007.SPS8_110_jimmy_susy.merge.AOD.e530_s765_s767_r1207_r1210 • Different simulation/geometry and reconstruction than the fast sim samples I have generated – still it reveals a problem with Atlfast II that effects this analysis

  3. 7 TeV MC Samples • Most of the 7 TeVmontecarlo has now been redone with the same new simulation and reconstruction version as the full simulation SPS8 point • Some of the old 7 TeV datasets have been deleted, some have not

  4. Object Selections (egamma) • Photons • PT> 20 GeV, eta < 2.5, isem – PhotonTight • Duplicate cluster removal – detlaR < 0.01 • A PT>40 GeV was also tried • Electrons • PT > 20 GeV, eta < 2.5, isem – ElectronLoose • Duplicate cluster removal – detlaR < 0.01

  5. Other Object Selections • Jets • AntiKt4H1TopoJets, Et > 20 GeV, and eta < 2.5 • Muons • isCombinedMuon() • 0<=matchChi2<=100 • pt > 10 GeV && |eta| < 2.5 • Overlap removal • Photons conversions removed from electrons (deltaR – 0.2) • Photons plus electrons of at least loose quality removed from jets (deltaR - 0.4)

  6. Other Definitions • HT is scalar sum of the et of the selected photons, leptons, and jets • NO missing et included • SumET – variable is taken directly from the missing et container in the AOD • The Sum ET variable was used instead of HT (which was used previously) in the following analysis

  7. SumET versus HT

  8. Photon Isolation • Different types of isolation being looked at for the analysis • None • ‘Historical’ - etcone20/et < 0.1 • Official egamma (isem bit 29) • Similar etcone20/et < some value and ptcone20/pt < some other value where those values vary as a function of photon pt and eta • SPS8 Λ=110 Signal efficiency (requiring 2 photons) • No isolation – 51% • ‘Historical isolation – 47% • Egamma isolation – 41% • Looking at several of the background samples the egamma isolation is not always more severe than the historical one

  9. Significances for 100pb-1

  10. Conclusions/Fast Sim Issues • This significance is much lower than previously quoted. This appears to be due to an issue that we discovered with the fast simulation. • Significance for the ‘historical’ iso cut option decreased from 4.1 to 2.7 • The fast sim appears to have an issue with jets in terms of number/pt spectrum which affects the HT variable • The fast sim sample has ~2 times as many jets. • The pt spectrum of the jets in the fast sim is harder • The scalar sum of the et in the jets is not consistent with the sumet in the fast sim (it is in the full sim). • Oddly the sum_et variable is consistent between the fast and full simulation. While the HT is not. • The full HT and sum_et are consistent with each other while for the fast sim the HT is consistently higher

  11. Fast/Full Comparison Plots • Following plots are comparing variables in the fast sim versus full SPS8 Λ=110 TeV point • Looking at the objects in the containers with no cuts applied • MetRef_Finaland AntiKt4H1TopoJets containers were used • Missing ET and photon number and pt spectrum seem consistent between fast and full sim

  12. Jet Number Comparison --- Atlfast II --- Full sim

  13. Jet Pt Spectrum Comparison Normalized to same number of jets --- Atlfast II --- Full sim pt [MeV]

  14. Missing ET Comparison --- Atlfast II --- Full sim MET [MeV]

  15. Sum ET Comparison --- Atlfast II --- Full sim Sum ET [MeV]

  16. Photon PT Comparison --- Atlfast II --- Full sim pt [MeV]

  17. Further Issues • Looking at the fast sim about 13% of the events have a scalar sum of the et of jets that exceeds the sum et • Sum by more than 50 GeV! • For the full simulation only 4 events out of 9987 events have a scalar sum of the jets et that is higher than the sum et variable • Exceeds by ~10 GeV or less • This talk: http://indico.cern.ch/conferenceDisplay.py?confId=89746 seems to show issues with the jets in the fast sim as well

  18. Conclusions • Exclusions above the Tevatron limit are still possible with ~100pb-1 • There appears to be issues with Atlfast II and jets that lead us to previous over-estimate the signal when using the jets to calculate HT • Using cuts based on jets with Atlfast II does not appear safe without validation (note - these Atlfast II samples were made in 15.6.3.6)

  19. Backup

More Related