1. HI July Exercise and Muon DQM preparation Mihee Jo 2010-09-011Mihee Jo / Lab meeting

2. Contents 1.July exercise 1.Introduction 2.Procedure and summary of results 3.Double peak in hydjet MC 2.Muon DQM preparation 1.Introduction 2.Progress on the muon POG DQM checking 3.Summary and plan 2010-09-012Mihee Jo / Lab meeting

3. Introduction of July Exercise Prepare and practice real HI data analysis –With RECO MC data, do analysis like real analysis –To know what is missing, what is needed, how to do something, and how to communicate each other and co-work tightly together In di-lepton group –We will focus on the Z0 analysis –Analysis tasks Data processing (RAW → RECO → Skim0) Check (di)muons in the data Signal extraction Acceptance and efficiency correction Yield and cross section 2010-09-01Mihee Jo / Lab meeting3 July Exercise

4. Basic Info and Data Processing July exercise dataset –AMPT Minbias –AMPT Minbias + Z0 embedded –MC for di-lepton group : HYDJET Minbias + Z0 embedded Data processing –At first, RAW data is delivered from the runs –Reconstruct RAW and it gives RECO data –Skim RECO to select effective event and reduce data size For different physics interests, different skimming is applied. Skim0 for di-lepton group : Take a event if it has at least 1 muon In the Minbias case, skim0 reduces # of events about 53% TWiki : https://twiki.cern.ch/twiki/bin/view/CMS/DileptonJulyExercise 2010-09-01Mihee Jo / Lab meeting4 July Exercise

5. Single Muon Distributions For di-lepton PInG, I took the jobs that –Improve “DimuonAnalyzer” which is common analysis tool for di-lepton PInG –Make distributions of muons with July exercise data Single muon distribution with new DimuonAnalyzer 2010-09-01Mihee Jo / Lab meeting5 July Exercise

6. Di-muon Distributions In AMPT (July exercise data), clear Z0 peak is shown, but hydjet isn’t. –Second peak at 60~80 GeV/c 2 becomes dominated at higher pt, because of pythia setting 2010-09-01Mihee Jo / Lab meeting6 July Exercise Pt > 12 GeV/c

7. Double peak in Hydjet Sometimes very energetic gamma is decayed from muon In the pgun only data, it also doesn’t have double peak like AMPT Now, we are suspecting the generator → try to find out exact reason now 2010-09-01Mihee Jo / Lab meeting7 July Exercise

8. Selection and Signal Extraction Analysis on global muons only –Also looked at Stand ‐ alone muons. First Z was combination of STA muons but that data sample had wrong vertices. Signal counting is done by fitting –Pol1 + Gaussian : Simple counting above pol1 (central method) –Pol1 + Relativistic Breit ‐ Wigner We had no background (bb, Drell ‐ Yan...) to subtract 2010-09-01Mihee Jo / Lab meeting8 July Exercise

9. Mass Plot vs. P t 2010-09-01Mihee Jo / Lab meeting9 July Exercise

10. Mass Plot vs. Rapidity 2010-09-01Mihee Jo / Lab meeting10 July Exercise

11. Mass Plot vs. Centrality 2010-09-01Mihee Jo / Lab meeting11 July Exercise

12. Integrated Mass Plot 2010-09-01Mihee Jo / Lab meeting12 July Exercise

13. Acceptance x Efficiency The number of reconstructed Z0 was calculated after Gauss + Pol1 fitting (same as signal extraction) Count number of Z0 for every p t, rapidity, centrality bins 2010-09-01Mihee Jo / Lab meeting13 July Exercise

14. Total Yield and Cross Section In principle we would quote –dN/dy (|y Z |<2.4) and subset of these –then correct for luminosity to get a cross section Systematic uncertainties not estimated bin by bin, but should be ~ 10% 2010-09-01Mihee Jo / Lab meeting14 July Exercise

15. Muon DQM preparation Purpose –Investigate the existing pp DQM histograms, and decide on a reasonable number for HI –We have very short HI run, so commissioning should be done very quickly and correctly –With efficient DQM histograms, it is easier to select good runs Work with muon POG (Physics Object Group) and Physics DQM –Those histograms are independent to detector DQM –Setting up cuts/thresholds of detector DQM could be done each DPG and we can help them if there is a problem during HI data taking 2010-09-01Mihee Jo / Lab meeting15 HI muon DQM

16. To Do To do list (Done, On going) –Check existing DQM histograms with Heavy Ion MC sample –For muon related histograms, compare Heavy Ion MC sample results to pp collision data –Add/modify appropriate configurations/cuts for HI data if we need –Add histograms for HI data GlobalMuon, StandAloneMuon, hiSelectedTracks as a function of centrality Dimuon unlike sign dqm Z yield / prescale, Z yield / lumi –Those histograms have also other di-muon object version (J/psi, Υ) TWiki: https://twiki.cern.ch/twiki/bin/view/Main/HIDQMMuon 2010-09-01Mihee Jo / Lab meeting16 HI muon DQM

17. Example Histograms 2010-09-01Mihee Jo / Lab meeting17 HI muon DQM

18. Too Few Global Muons We expect more global muons! –Is this a problem of HI muon reconstruction? It seems lots of tracker muon – standalone muon matching is failed 2010-09-01Mihee Jo / Lab meeting18 HI muon DQM

19. Summary and Plan We are preparing heavy ion data taking and analysis in various ways –July exercise was great opportunity to learn lots of basics Also efficient teamwork! A couple of problems came out and we are investigating on them –Muon DQM isn’t need modification too much But number of global muons should be investigated because this could affect on the DQM histograms Co-work with pp DQM experts to make di-muon object DQM histograms 2010-09-01Mihee Jo / Lab meeting19 HI muon DQM